To see the other types of publications on this topic, follow the link: Controlled released.
Journal articles on the topic 'Controlled released'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Controlled released.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Broschat, Timothy K. "Release Rates of Controlled-Release and Soluble Magnesium Fertilizers." HortTechnology 7, no. 1 (1997): 58–60. http://dx.doi.org/10.21273/horttech.7.1.58.
Full textAbstract:
Release rates at 21 °C were determined in sand columns for 12 commercially available soluble and controlled-release Mg fertilizers. Lutz Mg spikes, K2SO4, MgSO4, MgSO4·H2O, and MgSO4·7H2O released their Mg within 2 to 3 weeks. Within the first 6 weeks, MgO·MgSO4 released its soluble Mg fraction, but little release occurred thereafter. Dolomite and MgO released <5% of their Mg over 2 years while MagAmp released <20% of its Mg. Florikan 1N-0P-26K-4Mg types 100 and 180 exhibited typical controlled-release fertilizer characteristics, with most of their Mg release occurring during the first 15 weeks.
2
Zhao, Xin, Baolin Zhang, Sancai Liu, and Xiushi Yang. "Evaluation of efficiency of controlled-release N fertiliser on tartary buckwheat production." Plant, Soil and Environment 67, No. 7 (2021): 399–407. http://dx.doi.org/10.17221/32/2021-pse.
Full textAbstract:
To provide reference for scientific management of nitrogen (N) fertiliser on tartary buckwheat, the effects of the mixed application of controlled-release N fertiliser (a kind of thermoplastic polymer-coated urea types that are characterised by a semi-permeable membrane) and common urea was studied in the main tartary buckwheat production area in China. In 2018 and 2019, a two-year field experiment was conducted a randomised block design with five treatments: (1) no nitrogen fertilisation (CK); (2) 100% N from common urea (T1); (3) 15% N from controlled-released urea fertiliser (plastic coated) + 85% N from common urea (T2); (4) 30% N from controlled-released fertiliser + 70% N from urea (T3); (5) 45% N from controlled-released fertiliser + 55% N of urea (T4). The N fertilisation rate was 90 kg N/ha in all fertilisation treatments. The results showed: (1) the mixed application of controlled-release N fertiliser and common urea was conductive to enhance the yield, dry mass, N uptake and apparent N fertiliser efficiency (NFE), compared with a single application of common urea. In two seasons, NFE was 38.6% (T1), 48.6% (T2), 53.6% (T3) and 53% (T4), separately; (2) the mixed application of controlled-release N fertiliser and common urea could significantly increase the soil inorganic N content in the soil surface layer and decreased the leaching loss of N; (3) with the increasing ration of controlled-release N fertiliser, the tendency of increasing N content of crop uptake and soil residual and decreasing rate of N loss and N surplus was visible. Overall, considered the indicators of grain yield, input cost, N utilisation and N balance, the suitable N fertilisation mode for tartary buckwheat production is the mixed application of 30% controlled-release N fertiliser and 70% common urea when 90 kg N/ha is applied.
3
Broschat, Timothy K. "Release Rates of Soluble and Controlled-release Boron Fertilizers." HortTechnology 18, no. 3 (2008): 471–74. http://dx.doi.org/10.21273/horttech.18.3.471.
Full textAbstract:
The relative release rates of boron (B) from nine soluble and controlled-release B fertilizer sources were determined in sand leaching columns at 21 °C. Solubor was almost completely leached from the sand within 5 weeks. Boric oxide released the majority of its B within 7 weeks, whereas Dehybor provided B for up to 13 weeks. Granubor release rates were linear through ≈12 weeks. The five products containing calcium or sodium calcium borates released B much more slowly, with probertite and ulexite being the most rapid followed by B32 G, colemanite, and B38 G. B38 G released only ≈40% of its B content during the 104-week leaching study. The rapid release and high B concentrations associated with Solubor suggest a greater potential for phytotoxicity with this source than other slower-release sources.
4
BUONOCORE, G. G., M. SINIGAGLIA, M. R. CORBO, A. BEVILACQUA, E. LA NOTTE, and M. A. DEL NOBILE. "Controlled Release of Antimicrobial Compounds from Highly Swellable Polymers." Journal of Food Protection 67, no. 6 (2004): 1190–94. http://dx.doi.org/10.4315/0362-028x-67.6.1190.
Full textAbstract:
The suitability of antimicrobial release films made from highly swellable polymers for use in food packaging was evaluated. The possibility of modulating the release kinetics of active compounds either by regulating the degree of cross-link of the polymer matrix or by using multilayer structures was addressed. The release kinetics of lysozyme, nisin, and sodium benzoate (active compounds with different molecular weights) were determined at ambient temperature (25°C). The effectiveness of the proposed active films in inhibiting microbial growth was addressed by determining the antimicrobial efficiency of the released active compounds. Micrococcus lysodeikticus, Alicyclobacillus acidoterrestris, and Saccharomycescerevisiaewere used to test the antimicrobial efficiency of released lysozyme, nisin, and sodium benzoate, respectively. Results indicate that the release kinetics of both lysozyme and nisin can be modulated through the degree of cross-link of the polymer matrix, whereas multilayer structures need to be used to control the release kinetics of sodium benzoate. All the active compounds released from the investigated active films were effective in inhibiting microbial growth.
5
Mutagond, Chetankumar, Vinod M R, Vijapure V M, et al. "Formulation and Evaluation of Spray Dried Microspheres of Controlled Release Ramipril." International Journal of Pharmaceutical Sciences and Nanotechnology 11, no. 2 (2018): 4059–66. http://dx.doi.org/10.37285/ijpsn.2018.11.2.8.
Full textAbstract:
The present study sought to develop and evaluate spray-dried microspheres of chitosan and xanthan gum for controlled release of ramipril, a widely used antihypertensive drug. The prepared microspheres were characterized by particle size analysis, scanning electron microscopic studies, differential scanning calorimetric analysis, Fourier transform infrared spectroscopy analysis, X-ray diffraction studies, drug entrapment efficiency, and in-vitro drug release study. The prepared microspheres were spherical in shape and freely flowing. The size of the microspheres was in the range of 25.7 to 47.4 µm and the drug entrapment efficiency was in the range of 74.68% to 90.44%. TheDSC analysis and X-ray diffraction studies indicated that the drug was uniformly dispersed in amorphous state in the microspheres. The in-vitro drug release indicated that the spray-dried microspheres prepared with chitosan alone were not suitable for controlled released delivery of drug as maximum amount of drug was released within 5 hrs. Whereas microspheres prepared by xanthan gum released small amount of drug within 5 hrs and more amount of drug was controlled released that fit the therapeutic needs. Drug release mechanism followed non-Fickian transport. These suggest the formulation potential of chitosan and xanthan gum for spray-dried microspheres for controlled release of ramipril
6
Reddy, Shiv K. "A Novel Test for Evaluation of Controlled-release Fertilizers." HortScience 31, no. 4 (1996): 675b—675. http://dx.doi.org/10.21273/hortsci.31.4.675b.
Full textAbstract:
Various methods are used to evaluate the release characteristics of coated, controlled-release fertilizers. These methods include measuring the nutrients released into water or remaining in the prills or measuring the growth and nutrient content of the plants grown. Such methods do not show the release mechanism of the fertilizers. A simple test was developed that actually shows how nutrients are released from coated fertilizer prills that contain potassium. When prills of commercial products were placed in 1.5% aqueous solution of sodium tetraphenyl boron, potassium released from the prills combined with sodium tetraphenyl boron and formed a white precipitate. The precipitate patterns revealed that some new prills had large cracks or imperfect coating, thus releasing their nutrients instantly and prematurely. Over time, individual prills within the same fertilizer showed different release behaviors—from no release to release through tiny holes in the coating to release by rupture or bursting of the coating. This test is particularly useful for detecting coating defects during manufacture or subsequent damage to coating, as during incorporation of the prills into growing media. (Provisional patent application filed for this method.)
7
Liu, Lu, Tianlin Shen, Yuechao Yang, et al. "Bio-based Large Tablet Controlled-Release Urea: Synthesis, Characterization, and Controlled-Released Mechanisms." Journal of Agricultural and Food Chemistry 66, no. 43 (2018): 11265–72. http://dx.doi.org/10.1021/acs.jafc.8b04042.
Full text
8
Chen, Lei, Robert Nixon, and Guillaume De Bo. "Force-controlled release of small molecules with a rotaxane actuator." Nature 628, no. 8007 (2024): 320–25. http://dx.doi.org/10.1038/s41586-024-07154-0.
Full textAbstract:
AbstractForce-controlled release of small molecules offers great promise for the delivery of drugs and the release of healing or reporting agents in a medical or materials context1–3. In polymer mechanochemistry, polymers are used as actuators to stretch mechanosensitive molecules (mechanophores)4. This technique has enabled the release of molecular cargo by rearrangement, as a direct5,6 or indirect7–10 consequence of bond scission in a mechanophore, or by dissociation of cage11, supramolecular12 or metal complexes13,14, and even by ‘flex activation’15,16. However, the systems described so far are limited in the diversity and/or quantity of the molecules released per stretching event1,2. This is due to the difficulty in iteratively activating scissile mechanophores, as the actuating polymers will dissociate after the first activation. Physical encapsulation strategies can be used to deliver a larger cargo load, but these are often subject to non-specific (that is, non-mechanical) release3. Here we show that a rotaxane (an interlocked molecule in which a macrocycle is trapped on a stoppered axle) acts as an efficient actuator to trigger the release of cargo molecules appended to its axle. The release of up to five cargo molecules per rotaxane actuator was demonstrated in solution, by ultrasonication, and in bulk, by compression, achieving a release efficiency of up to 71% and 30%, respectively, which places this rotaxane device among the most efficient release systems achieved so far1. We also demonstrate the release of three representative functional molecules (a drug, a fluorescent tag and an organocatalyst), and we anticipate that a large variety of cargo molecules could be released with this device. This rotaxane actuator provides a versatile platform for various force-controlled release applications.
9
Sunil, Songa Ambedkar, Meka Venkata Srikanth, Nali Sreenivasa Rao, Sakamuri Balaji, and Kolapalli Venkata Ramana Murthy. "Design and evaluation of lornoxicam bilayered tablets for biphasic release." Brazilian Journal of Pharmaceutical Sciences 48, no. 4 (2012): 609–19. http://dx.doi.org/10.1590/s1984-82502012000400004.
Full textAbstract:
The objective of the present investigation was to develop bilayered tablets of lornoxicam to achieve biphasic release pattern. A bilayered tablet, consisting of an immediate and controlled release layer, was prepared by direct compression technique. The controlled release effect was achieved by using various hydrophilic natural, semi synthetic and synthetic controlled release polymers such as xanthan gum, hydroxypropyl methylcellulose (HPMC) and polyethylene oxide (PEO) to modulate the release of the drug. The in vitro drug release profiles showed the biphasic release behavior in which the immediate release (IR) layer containing the lornoxicam was released within 15 minutes, whereas the controlled release (CR) layer controlled the drug release for up to 24 h. All the bilayered tablets formulated have followed the zero order release with non-Fickian diffusion controlled release mechanism after the initial burst release. FTIR studies revealed that there was no interaction between the drug and polymers used in the study. Statistical analysis (ANOVA) showed no significant difference in the cumulative amount of drug release after 15 min, but significant difference (p < 0.05) in the amount of drug released after 24 h from optimized formulations was observed. Based on the release kinetic parameters obtained, it can be concluded that xanthan gum polymer was suitable for providing a biphasic release of lornoxicam.
10
Muharam, Salih, Afria Fitri, Lela Mukmilah Yuningsih, Yulia Mariana Tessa Ayudia Putri, and Isnaini Rahmawati. "Synthesis and Characterization of Controlled-Release Urea Fertilizer from Superabsorbent Hydrogels." Indonesian Journal of Chemistry 20, no. 3 (2020): 616. http://dx.doi.org/10.22146/ijc.44230.
Full textAbstract:
It is very important to develop controlled-release fertilizers to ensure efficiency and environmental protection. This study aims to make a superabsorbent hydrogel-based controlled-release urea fertilizer. Superabsorbent hydrogels were prepared from the cellulose of corn cobs cross-linking with epichlorohydrin, and then an amount of urea as a fertilizer was stored inside the hydrogels (GEL-A). The GEL-A functionalization with carboxy-methyl was also carried out in this study to improve the hydrophilicity of hydrogels (GEL-B). GEL-A and GEL-B were immersed in water at a certain pH and temperature range and the urea concentration released from the hydrogels was monitored by a spectrophotometer. The results showed that the urea released by GEL-A and GEL-B was not much different. Respectively, the urea efficiency of GEL-A and GEL-Bwas around 5.29% and 5.56% for 180 min. The urea released from both hydrogels was not significantly affected by changes in the temperature of the solution. Urea release was influenced by pH, and the rate of urea release of GEL-B was faster than GEL-A, so pH control was needed in the application of this slow-release fertilizer.
11
Wang, An Na, Li Gen Wu, Lin Lu Jia, Xiu Ling Li, and Yu Dan Sun. "Alginate-Chitosan Microspheres for Controlled Release of Tea Polyphenol." Advanced Materials Research 152-153 (October 2010): 1726–29. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.1726.
Full textAbstract:
Tea polyphenol loaded alginate-chitosan microspheres were prepared by ionic gelation method for controlling tea polyphenol release by using various combinations of chitosn and Ca2+ as cation and alginate as anion.Scanning electron microscopy were used to investigate the surface characteristics of tea polyphenol loaded microspheres. These microencapsulated beads were evaluated as a pH-sensitive system for delivery of tea polyphenol. The main advantage of this system is that all procedures used were performed in aqueous medium which may preserve the tea polyphenol bioactivity. At pH7.4, the amounts of tea polyphenol released increased significantly as compared to those released at pH1.2. It is evident that the rate of tea polyphenol release could be controlled by changing the chitosan and the calcium chloride concentrations.
12
Sandomierski, Mariusz, Martyna Chojnacka, Maria Długosz, et al. "Mesoporous Silica Modified with Polydopamine and Zinc Ions as a Potential Carrier in the Controlled Release of Mercaptopurine." Materials 16, no. 12 (2023): 4358. http://dx.doi.org/10.3390/ma16124358.
Full textAbstract:
Mercaptopurine is one of the drugs used in the treatment of acute lymphoblastic leukemia. A problem with mercaptopurine therapy is its low bioavailability. This problem can be solved by preparing the carrier that releases the drug in lower doses but over a longer period of time. In this work, polydopamine-modified mesoporous silica with adsorbed zinc ions was used as a drug carrier. SEM images confirm the synthesis of spherical carrier particles. The particle size is close to 200 nm, allowing for its use in intravenous delivery. The zeta potential values for the drug carrier indicate that it is not prone to agglomeration. The effectiveness of drug sorption is indicated by a decrease in the zeta potential and new bands in the FT-IR spectra. The drug was released from the carrier for 15 h, so all of the drug can be released during circulation in the bloodstream. The release of the drug from the carrier was sustained, and no ‘burst release’ was observed. The material also released small amounts of zinc, which are important in the treatment of the disease because these ions can prevent some of the adverse effects of chemotherapy. The results obtained are promising and have great application potential.
13
Ari, Betul, Mehtap Sahiner, Selin Sagbas Suner, Sahin Demirci, and Nurettin Sahiner. "Super-Macroporous Pulluan Cryogels as Controlled Active Delivery Systems with Controlled Degradability." Micromachines 14, no. 7 (2023): 1323. http://dx.doi.org/10.3390/mi14071323.
Full textAbstract:
Here, super-macroporous cryogel from a natural polysaccharide, pullulan was synthesized using a cryo-crosslinking technique with divinyl sulfone (DVS) as a crosslinker. The hydrolytic degradation of the pullulan cryogel in various simulated body fluids (pH 1.0, 7.4, and 9.0 buffer solutions) was evaluated. It was observed that the pullulan cryogel degradation was much faster in the pH 9 buffer solution than the pH 1.0 and 7.4 buffer solutions in the same time period. The weight loss of the pullulan cryogel at pH 9.0 within 28 days was determined as 31% ± 2%. To demonstrate the controllable drug delivery potential of pullulan cryogels via degradation, an antibiotic, ciprofloxacin, was loaded into pullulan cryogels (pullulan-cipro), and the loading amount of drug was calculated as 105.40 ± 2.6 µg/mg. The release of ciprofloxacin from the pullulan-cipro cryogel was investigated in vitro at 37.5 °C in physiological conditions (pH 7.4). The amount of drug released within 24 h was determined as 39.26 ± 3.78 µg/mg, which is equal to 41.38% ± 3.58% of the loaded drug. Only 0.1 mg of pullulan-cipro cryogel was found to inhibit half of the growing Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) colonies for 10 min and totally eradicated within 2 h by the release of the loaded antibiotic. No significant toxicity was determined on L929 fibroblast cells for 0.1 mg drug-loaded pullulan cryogel. In contrast, even 1 mg of drug-loaded pullulan cryogel revealed slight toxicity (e.g., 66% ± 9% cell viability) because of the high concentration of released drug.
14
Kumar, Vipan, Vidhi Jain, and Manmeet Singh Saluja. "Optimization of Spirapril Controlled Release Floating Tablet Using 32 Central Composite Design." Journal of Biomedical and Pharmaceutical Research 12, no. 1 (2023): 49–56. http://dx.doi.org/10.32553/jbpr.v12i1.957.
Full textAbstract:
The aim of present investigation was to develop efficient controlled release floating tablet (CRFT) of Spirapril. Floating dosage form for gastric retention has potential to use as controlled-release drug delivery systems which providing opportunity for both local and systemic drug action. The tablets were prepared by using wet granulation techniques using PVP K 30, SFG and Acrypol 934. A 32 full factorial design (CCD) was applied to optimize two independent variables at three different levels by varied response variables. Two independent variables i.e. amount of SFG (i.e., polymer X1) and amount of Acrypol 934 (i.e., polymer X2) were varied at three different levels that was coded for low, medium and high (-1, 0, 1 respectively). The response variables T6 (cumulative % amount of drug released in 6 hr) (Y1), T12 (cumulative % amount of drug released in 12 hr) (Y2), Q50 (time in minutes required to 50 % of drug released) (Y3), FLT (Y4), TFT (Y5), and Swelling Index after 12 hr (Y6) were selected for present study. ANOVA study was also employed to optimize for best fitted quadratic model. Compressed matrices exhibited Super case-II transport drug release kinetics approaching zero- order, as the value of release rate exponent (n) varied between 0.9430 and 1.0133. Formulation A4 was the optimized best formulation from the response surface plot and contour plot of all the formulation.
15
Lorenzon, Mauro, Alberto Pozzebon, and Carlo Duso. "Biological control of spider mites in North-Italian vineyards using pesticide resistant predatory mites." Acarologia 58, Suppl (2018): 98–118. http://dx.doi.org/10.24349/acarologia/20184277.
Full textAbstract:
The success of phytoseiid mite releases to control spider mites [Eotetranychus carpini (Oudemans) and Panonychus ulmi (Koch)] on grapevines can be influenced by pesticide use and competition with local predatory mites. In field experiments we evaluated the effect of the release of Kampimodromus aberrans (Oudemans) and Typhlodromus pyri Scheuten strains showing field resistance to organophosphates and dithiocarbamates. Predatory mites were released in two vineyards infested by spider mites despite the occurrence of Amblyseius andersoni (Chant) and/or Phytoseius finitimus Ribaga. Single or mixed releases were planned. Spider mite populations were not effectively controlled by local predatory mites while successful control was achieved by released species. The effects of releases were higher in the second experimental year. In most cases A. andersoni densities were reduced by T. pyri and K. aberrans releases. Ph. finitimus suffered less than A. andersoni from intraguild predation. Among released species, the effect of the presence of a competitor was higher on T. pyri than on K. aberrans. Results suggest that the outcome of intraguild predation is prey-mediated. The equilibrium level between K. aberrans and T. pyri may depend on which spider mite species is the shared prey. The implications in management of spider mites on grapevines are discussed.
16
Nanda, Himansu Sekhar, Shangwu Chen, Qin Zhang, Naoki Kawazoe, and Guoping Chen. "Collagen Scaffolds with Controlled Insulin Release and Controlled Pore Structure for Cartilage Tissue Engineering." BioMed Research International 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/623805.
Full textAbstract:
Controlled and local release of growth factors and nutrients from porous scaffolds is important for maintenance of cell survival, proliferation, and promotion of tissue regeneration. The purpose of the present research was to design a controlled release porous collagen-microbead hybrid scaffold with controlled pore structure capable of releasing insulin for application to cartilage tissue regeneration. Collagen-microbead hybrid scaffold was prepared by hybridization of insulin loaded PLGA microbeads with collagen using a freeze-drying technique. The pore structure of the hybrid scaffold was controlled by using preprepared ice particulates having a diameter range of 150–250 μm. Hybrid scaffold had a controlled pore structure with pore size equivalent to ice particulates and good interconnection. The microbeads showed an even spatial distribution throughout the pore walls.In vitroinsulin release profile from the hybrid scaffold exhibited a zero order release kinetics up to a period of 4 weeks without initial burst release. Culture of bovine articular chondrocytes in the hybrid scaffold demonstrated high bioactivity of the released insulin. The hybrid scaffold facilitated cell seeding and spatial cell distribution and promoted cell proliferation.
17
Gao, Qiang, Zong Wei Chen, Jun Xu, and Yao Xu. "pH-Controlled Drug Release from Mesoporous Silica Spheres with Switchable Gates." Advanced Materials Research 236-238 (May 2011): 2142–45. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.2142.
Full textAbstract:
Mesoporous silica sphere (MSS) with switchable gates was prepared by the graft of pH-sensitive propyldiethylenetriamine groups (multiamine chains) around mesopore outlets. The textural parameters of the resultant material had been analyzed. In the following test of in vitrodrug release, the gated mesoporous material showed high response to solution pH. At high pH (pH 7.5), ibuprofen (IBU) that loaded in this carrier released rapidly and completely (within 2 h); at low pH (pH 4.0 or 5.0), only a small part of the IBU (13 wt%) was slowly released from this carrier and the most of IBU was effectively confined in mesopores.
18
Medina, L. Carolina, Jerry B. Sartain, Thomas A. Obreza, William L. Hall, and Nancy J. Thiex. "Evaluation of a Soil Incubation Method to Characterize Nitrogen Release Patterns of Slow- and Controlled-Release Fertilizers." Journal of AOAC INTERNATIONAL 97, no. 3 (2014): 643–60. http://dx.doi.org/10.5740/jaoacint.13-065.
Full textAbstract:
Abstract Several technologies have been proposed to characterize the nutrient release patterns of slow- release fertilizers (SRF) and controlled-release fertilizers (CRF) during the last few decades. These technologies have been developed mainly by manufacturers, and are product-specific, based on the regulation and analysis of each SRF and CRF product. Despite previous efforts to characterize SRF and CRF materials, no standardized, validated method exists to assess their nutrient release patterns. However, the increased production and distribution of these materials in specialty and nonspecialty markets requires an appropriate method to verify product claims and material performance. A soil incubation column leaching procedure was evaluated to determine its suitability as a standard method to estimate nitrogen (N) release patterns of SRFs and CRFs during 180 days. The influence of three soil/sand ratios, three incubation temperatures, and four soils on method behavior was assessed using five SRFs and three CRFs. In general, the highest soil/sand ratio increased the N release rate of all materials, but this effect was more marked for the SRFs. Temperature had the greatest influence on N release rates. For CRFs, the initial N release rates and the percentage N released/day increased as temperature increased. For SRFs, raising the temperature from 25 to 35°C increased initial N release rate and the total cumulative N released, and almost doubled the percentage released/day. The percentage N released/day from all products generally increased as the texture of the soil changed from sandy to loamy (Iowa&gt;California&gt;Pennsylvania&gt;Florida). The soil incubation technique was demonstrated to be robust and reliable for characterizing N release patterns from SRFs and CRFs. The method was reproducible, and variations in soil/sand ratio, temperature, and soil had little effect on the results.
19
Fan, Zhaofei, James A. Moore, Bahman Shafii, and Harold L. Osborne. "Three-Year Response of Ponderosa Pine Seedlings to Controlled-Release Fertilizer Applied at Planting." Western Journal of Applied Forestry 17, no. 3 (2002): 154–64. http://dx.doi.org/10.1093/wjaf/17.3.154.
Full textAbstract:
Abstract Four controlled-release fertilizers (fast release [FR], moderate release [MR], slow release [SR] and slow release with micronutrients extended [ME]) were applied, at rates of 0, 5, 15 and 30 g/seedling, to ponderosa pine seedlings (Pinus ponderosa Doug. ex Laws) immediately after planting. Compared to the controls, the 5 and15 g/seedling of FR or ME fertilizer produced significantly greater caliper growth and the 5 and 15 g/seedling of ME fertilizer and 15 and 30 g of FR fertilizer produced significantly greater height growth after 3 yr. Mortality occurred mainly during the first growing season and varied substantially with fertilizer types and dosage. High dosage (30 g/seedling) generally caused more mortality than other dosage levels. Seventy-eight, 54, 51, and 36% of total nutrients had been released from the FR, MR, SR and ME products, respectively, by late August of the first growing season. Early in the second growing season, the FR product had released 98% of its total nutrients, and the MR, SR, and ME products had released over 90% of their nutrients. The best fertilizer treatment, 15 g of the ME product, produced a 21% diameter increase and a 30% height increase 3 yr after treatment. The relative magnitude of the growth responses is similar to those observed from other adjacent placement, controlled-release, seedling fertilization studies in the Northwest. West. J. Appl. For. 17(3):154–164.
20
Ge, Chunling, Johan S. Basuki, Jacinta White, et al. "Photothermal triggered protein release from an injectable polycaprolactone-based microspherical depot." Journal of Materials Chemistry B 5, no. 20 (2017): 3634–39. http://dx.doi.org/10.1039/c7tb00837f.
Full text
21
Wang, Ruibin, Ming Li, Margaret Anne Brennan, Don Kulasiri, Boli Guo, and Charles Stephen Brennan. "Phenolic Release during In Vitro Digestion of Cold and Hot Extruded Noodles Supplemented with Starch and Phenolic Extracts." Nutrients 14, no. 18 (2022): 3864. http://dx.doi.org/10.3390/nu14183864.
Full textAbstract:
Dietary phenolic compounds must be released from the food matrix in the gastrointestinal tract to play a bioactive role, the release of which is interfered with by food structure. The release of phenolics (unbound and bound) of cold and hot extruded noodles enriched with phenolics (2.0%) during simulated in vitro gastrointestinal digestion was investigated. Bound phenolic content and X-ray diffraction (XRD) analysis were utilized to characterize the intensity and manner of starch-phenolic complexation during the preparation of extruded noodles. Hot extrusion induced the formation of more complexes, especially the V-type inclusion complexes, with a higher proportion of bound phenolics than cold extrusion, contributing to a more controlled release of phenolics along with slower starch digestion. For instance, during simulated small intestinal digestion, less unbound phenolics (59.4%) were released from hot extruded phenolic-enhanced noodles than from the corresponding cold extruded noodles (68.2%). This is similar to the release behavior of bound phenolics, that cold extruded noodles released more bound phenolics (56.5%) than hot extruded noodles (41.9%). For noodles extruded with rutin, the release of unbound rutin from hot extruded noodles and cold extruded noodles was 63.6% and 79.0%, respectively, in the small intestine phase, and bound rutin was released at a much lower amount from the hot extruded noodles (55.8%) than from the cold extruded noodles (89.7%). Hot extrusion may allow more potential bioaccessible phenolics (such as rutin), further improving the development of starchy foods enriched with controlled phenolics.
22
Fehim, Korać, and Muratović Dinka. "Controlled release of ranitidine from conductive polypyrrole films." Technologica Acta 11, no. 2 (2019): 25–32. https://doi.org/10.5281/zenodo.2563064.
Full textAbstract:
Incorporation and controlled release of active substances from the conductive polypyrrole films by electric stimulation were investigated. Change of the redox state of the conductive polymer was induced by this stimulation, which allowed the incorporation and release of the drug at different rates. Polymerization of pyrrol on a stainless steel substrate was performed by cycling the potential 40 times in predetermined potential window, after which uniform polymeric film was formed and used as a medium for incorporation and release of the active substance. Stability of obtained films, as well as the electrochemical behaviour of ranitidine hydrochloride was investigated by cycling the potential of the film electrode in 0.9 % NaCl in the same potential window used for the polymerization. Uptake and release of the active substance was performed at constant potential and monitored by chronoamperometry. Although incorporation of the ranitidine hydrochloride was not obvious from the measured infrared spectra, incorporation and release was confirmed and quantified by monitoring the concentration of the active substance in the electrolyte. It was determined that maximum reversible uptake was 351 μg cm-2. However, successive potential stimuli did not result in the equal released quantity, as expected for the ideal controlled-release system based on conducting polymers.
23
Dutcher, James D. "Impact of Predatory Mite Releases on the Abundance of Pecan Leaf Scorch Mite (Acari: Tetranychidae)." Journal of Entomological Science 42, no. 4 (2007): 517–24. http://dx.doi.org/10.18474/0749-8004-42.4.517.
Full textAbstract:
Release of the predatory mites, Galendromus occidentalis (Nesbitt) and Phytoseuilis persimilis Athias-Henriot, suppressed or controlled populations of pecan leaf scorch mite (Eotetranychus hicoriae McGregor [Acari:Tetranychidae]) in an 18-yr-old ‘Desirable’ pecan orchard. Predators controlled a low population (4.4 pecan leaf scorch mites and eggs per leaf in untreated trees) of pecan leaf scorch mites in the 2002 season at 28 days after the release date. In 2003, both species of predatory mites were released at 500 and 1000 mites per tree in the center tree of a 25-tree, square plot (0.41 ha). Untreated trees had 63, 240, and 38 pecan leaf scorch mites and eggs per leaf at 6, 10, and 24 d postrelease, respectively. Pecan leaf scorch mites were controlled at this high population density in the release area 24 d after the release. Release of the mites at 500 and 1000 G. occidentalis mites per tree reduced the pecan leaf scorch mite infestation by 67 and 91%, respectively. Release of 500 and 1000 P. persimilis mites per tree reduced the pecan leaf scorch mite infestation by 90 and 98%, respectively. Predatory mite releases appear to provide an effective management tactic for pecan leaf scorch mite for pecan producers in Georgia.
24
Mizrahi, Limor, Rotem Kelman, Efrat Shtriker, et al. "Controlled Release of Hydrophilic Active Agent from Textile Using Crosslinked Polyvinyl Alcohol Coatings." Journal of Functional Biomaterials 16, no. 6 (2025): 216. https://doi.org/10.3390/jfb16060216.
Full textAbstract:
Functional fabrics embedded with active materials that can be released in a controlled manner upon external triggering have been explored for biomedical and cosmetic applications. This study introduces a method for the fabrication of nonwoven fabrics coated with crosslinked polyvinyl alcohol (PVA) for in situ encapsulation and controlled release of hydrophilic active agent, allantoin. Two types of crosslinked coatings were examined using citric acid (CA) or polyacrylic acid (PAA) as crosslinkers. Based on gel content, differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) analyses PVA:CA coatings exhibited a higher crosslinking density compared to PVA:PAA systems. Swelling behavior was measured at 62% after 30 min for PVA:PAA 7:3 films and 36% after 60 min for PVA:CA 7:3 crosslinked films. The release of allantoin from the coated fabrics was influenced by the coating thickness (250–330 µm), the formulation viscosity (8–250 cP), allantoin content (1.2–4.2 mg) and the molecular weight between crosslinks (MC) 1,000,000–494 g/mol. PVA:CA 7:3 coating allowed the controlled release of 97% allantoin over 8 h, whereas PVA:PAA 7:3 coating exhibited a more prolonged release profile, with 96% of allantoin released over 20 h. Kinetic analyses of the release profiles revealed a good agreement with zero-order release.
25
Reczkowski, Jakub, Maria Długosz, Maria Ratajczak, Adam Voelkel, and Mariusz Sandomierski. "Gelatin–Zinc Carrier as a New Method of Targeted and Controlled Release of Risedronate." Materials 17, no. 11 (2024): 2473. http://dx.doi.org/10.3390/ma17112473.
Full textAbstract:
The essence of drug delivery is to use an appropriate carrier that delivers the active substance to the appropriate pathogenic site at a specific time. This study aims to develop a novel drug carrier characterized by the controlled and targeted release of risedronate (RSD). The search for new routes to deliver RSD is important because oral delivery has many disadvantages. The carrier proposed in this work is composed of gelatin, polyphosphates, and zinc. The zinc contained in the carrier is responsible for coordinating the drug. The resulting material releases RSD in a controlled manner. The rate of delivery of the substance to the body depends on the pH of the environment. This study investigated the delivery of RSD in a neutral environment, where the process exhibited a prolonged and consistent release rate. This process has also been studied in an acidic environment, which accelerates the release of the drug. Mixed-environment studies were also conducted. Initially, the drug was released in a neutral environment, and then the conditions rapidly changed to acidic. In this case, the carrier demonstrated high stability and controlled release, adapting the rate of drug release to the prevailing environmental conditions. The presented results indicate the great potential of the new gelatin-based carrier in the delivery of risedronate.
26
Wang, Ruo-Mei, Qian Liu, Yu Zhang, Zhangyong Hong, and He-Fang Wang. "A thermo- and pH-responsive poly(N-isopropylacrylamide)–Mn–ZnS nanocomposite for controlled release and real-time photoluminescence tracking of doxorubicin." RSC Advances 6, no. 56 (2016): 50985–92. http://dx.doi.org/10.1039/c6ra10395b.
Full textAbstract:
A novel multifunctional poly(N-isopropylacrylamide)–Mn–ZnS (PMZS) nanocomposite was developed as a smart drug carrier for thermo- and pH-controlled release of doxorubicin (Dox) and real-time photoluminescence tracking of the released Dox.
27
Chou, Joshua, Tomoko Ito, Makoto Otsuka, Besim Ben-Nissan, and Bruce Milthorpe. "The Controlled Release of Simvastatin from Biomimetic Macrospheres." Key Engineering Materials 529-530 (November 2012): 461–64. http://dx.doi.org/10.4028/www.scientific.net/kem.529-530.461.
Full textAbstract:
Simvastatin has been shown to succesfully stimulate bone regeneration and attention has being focussed on developing appropriate delivery carriers for its release. The challenge of deliverying therapeutic concentration of pharmaceutical compunds has being the centre of focus in drug delivery developments. This study examines the in-vivo effects of simvastatin released from β-TCP macrospheres derived from coral exoxskeletons. The results indicates that the controlled release of simvastatin can promote bone formation comparable with direct injection. Furthermore the results showed that the release of simvastatin delivery rates can be controlled by additional coating of an apatite coating. Analysis by CT scans, SEM, amount of new bone formed and mechanical strength tests, showed that by controlling the release of simvastatin bone formation can be stimulated to a therapeutic level.
28
Nechifor, Gheorghe, Alexandra Raluca Grosu, Andreea Ferencz (Dinu), et al. "Simultaneous Release of Silver Ions and 10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles Impregnated Membranes." Membranes 12, no. 6 (2022): 557. http://dx.doi.org/10.3390/membranes12060557.
Full textAbstract:
The bio-medical benefits of silver ions and 10–undecenoic acid in various chemical-pharmaceutical preparations are indisputable, thus justifying numerous research studies on delayed and/or controlled release. This paper presents the effect of the polymer matrix in the simultaneous release of silver ions and 10–undecenoic acid in an aqueous medium of controlled pH and ionic strength. The study took into consideration polymeric matrices consisting of cellulose acetate (CA) and polysulfone (PSf), which were impregnated with oxide nanoparticles containing silver and 10–undecenoic acid. The studied oxide nanoparticles are nanoparticles of iron and silver oxides obtained by an accessible electrochemical method. The obtained results show that silver can be released, simultaneously with 10–undecenoic acid, from an impregnated polymeric membrane, at concentrations that ensure the biocidal and fungicidal capacity. Concentrations of active substances can be controlled by choosing the polymer matrix or, in some cases, by changing the pH of the target medium. In the studied case, higher concentrations of silver ions are released from the polysulfone matrix, while higher concentrations of 10–undecenoic acid are released from the cellulose acetate matrix. The results of the study show that a correlation can be established between the two released target substances, which is dependent on the solubility of the organic compound in the aqueous medium and the interaction of this compound with the silver ions. The ability of 10–undecenoic acid to interact with the silver ion, both through the carboxyl and alkene groups, contributes to the increase in the content of the silver ions transported in the aqueous medium.
29
Nakanishi, Ko, Yosuke Bando, Tomohiko Katsurayama, et al. "Controlled Ion Release Property of Glass Ionomer Cement Containing Nanoporous Silica Particles." Key Engineering Materials 720 (November 2016): 17–20. http://dx.doi.org/10.4028/www.scientific.net/kem.720.17.
Full textAbstract:
Controlled ion release property of nanoporous silica particles (NPS) were investigated using cationic fluorescent dye, rhodamine B. The dye was charged into a glass ionomer cements (GIC) pellet containing the particles and then the pellet were immersed into distilled water. The dye-release behavior was observed using a UV-vis. spectrophotometer. GIC containing NPS can release the dye for a couple of weeks, where as other samples released it only a few days. This result suggests that NPS has excellent sustained dye-release property.
30
Mohamed, Asmaa Abdelaziz, Noor Zuhair Kbah, and Osama N. Wennas. "Poly (lactic-co-glycolic acid) nanoparticles for drug delivery of rupatadine fumarate: development and evaluation." Pharmacia 70, no. (4) (2023): 1257–64. https://doi.org/10.3897/pharmacia.70.e110191.
Full textAbstract:
This study aimed to consolidate rupatadine fumarate (RF) into nanoparticles to control its release. Ten RF nanoparticles were developed by nanoprecipitation using poly (lactic-co-glycolic acid) (PLGA) , polyvinyl alcohol (PVA), and Poloxamer 407 (Kolliphor P 407) in different percentages. A valid reverse-phase HPLC method was developed to assess RF in the formulated nanoparticles. The RF nanoparticles were tested chemically and morphologically. RF nanoparticles containing PLGA and PVA and Kolliphor P 407 have zeta potentials ranging from -24.4 mV±0.24 to -26.7 mV±0.05, higher than other formulations, and their release profiles were optimised. The formula (RPX3) had the best zeta potential (-26.7 mV±0.05), released about 86% of RF after 8 h and extended for 24 h. In summary, the formulation (RPX3), including 2:10:3:1.5 ratios of the drug PLGA: PVA: Kolliphor P 407 was the optimised RF-loaded nanoparticles formulation.
31
Wan, Q., R. K. Xu, and X. H. Li. "Proton release by tea plant (Camellia sinensis L.) roots as affected by nutrient solution concentration and pH." Plant, Soil and Environment 58, No. 9 (2012): 429–34. http://dx.doi.org/10.17221/326/2012-pse.
Full textAbstract:
Solution culture experiments were conducted and the protons released were measured with an automatic titration system to determine the main factors affecting proton release by tea roots. Results indicated that the higher were the cation concentrations, the more protons were released from the roots, suggesting that tea roots took up a large amount of cations during growth, and then released protons to maintain charge balance of the plant body. The amount of protons released from tea roots at controlled pH was much higher than that in the treatments with uncontrolled pH. Stepwise multiple linear regression analysis showed that both NH<sub>4</sub><sup>+</sup>&nbsp;and Al(III) played distinct roles in proton release by tea plant roots. The uptake of Al(III) and NH<sub>4</sub><sup>+</sup>&nbsp;and subsequent release of protons may be an important mechanism for soil acidification in tea gardens.
32
Kocaaga, Banu, Ozge Kurkcuoglu, Melkon Tatlier, Gizem Dinler-Doganay, Saime Batirel, and Fatma Seniha Güner. "Pectin–Zeolite-Based Wound Dressings with Controlled Albumin Release." Polymers 14, no. 3 (2022): 460. http://dx.doi.org/10.3390/polym14030460.
Full textAbstract:
Hypoalbuminemia can lead to poor and delayed wound healing, while it is also associated with acute myocardial infarction, heart failure, malignancies, and COVID-19. In elective surgery, patients with low albumin have high risks of postoperative wound complications. Here, we propose a novel cost-effective wound dressing material based on low-methoxy pectin and NaA-zeolite particles with controlled albumin release properties. We focused on both albumin adsorption and release phenomena for wounds with excess exudate. Firstly, we investigated albumin dynamics and calculated electrostatic surfaces at experimental pH values in water by using molecular dynamics methods. Then, we studied in detail pectin–zeolite hydrogels with both adsorption and diffusion into membrane methods using different pH values and albumin concentrations. To understand if uploaded albumin molecules preserved their secondary conformation in different formulations, we monitored the effect of pH and albumin concentration on the conformational changes in albumin after it was released from the hydrogels by using CD-UV spectroscopy analyses. Our results indicate that at pH 6.4, BSA-containing films preserved the protein’s folded structure while the protein was being released to the external buffer solutions. In vitro wound healing assay indicated that albumin-loaded hydrogels showed no toxic effects on the fibroblast cells.
33
Sempeho, Siafu Ibahati, Hee Taik Kim, Egid Mubofu, Alexander Pogrebnoi, Godlisten Shao, and Askwar Hilonga. "Encapsulated Urea-Kaolinite Nanocomposite for Controlled Release Fertilizer Formulations." Journal of Chemistry 2015 (2015): 1–17. http://dx.doi.org/10.1155/2015/237397.
Full textAbstract:
Urea controlled release fertilizer (CRF) was prepared via kaolinite intercalation followed by gum arabic encapsulation in an attempt to reduce its severe losses associated with dissolution, hydrolysis, and diffusion. Following the beneficiation, the nonkaolinite fraction decreased from 39.58% to 0.36% whereas the kaolinite fraction increased from 60.42% to 99.64%. The X-ray diffractions showed that kaolinite was a major phase with FCC Bravais crystal lattice with particle sizes ranging between 14.6 nm and 92.5 nm. The particle size varied with intercalation ratios with methanol intercalated kaolinite > DMSO-kaolinite > urea-kaolinite (KPDMU). Following intercalation, SEM analysis revealed a change of order from thick compact overlapping euhedral pseudohexagonal platelets to irregular booklets which later transformed to vermiform morphology and dispersed euhedral pseudohexagonal platelets. Besides, dispersed euhedral pseudohexagonal platelets were seen to coexist with blocky-vermicular booklets. In addition, a unique brain-form agglomeration which transformed into roundish particles mart was observed after encapsulation. The nanocomposites decomposed between 48 and 600°C. Release profiles showed that 100% of urea was released in 97 hours from KPDMU while 87% was released in 150 hours from the encapsulated nanocomposite. The findings established that it is possible to use Pugu kaolinite and gum arabic biopolymer to prepare urea CRF formulations.
34
O'Hair, Stephen K., and Tiangen Wang. "In Situ Measurement of the Rate of NO-3 Release from Controlled-release Fertilizers." HortScience 32, no. 4 (1997): 592G—593. http://dx.doi.org/10.21273/hortsci.32.4.592g.
Full textAbstract:
Controlled-Released Fertilizer (CRF) has a great potential for applications in the nursery container industry. However, the specific mechanisms of the control are proprietary. The longevity claimed by manufacturers are unclear. The longevity of one CRF is claimed to be 2 to 3 months at 80 °F, resulting in a deviation of 30%. Thus, the actual release rate will have a 30% deviation from the claimed longevity. A preliminary study was conducted to test the longevity of two types of RCFs. 1.00 g (7.7% NO-3-N, fast release) and 1.30 g (5.9% NO-3-N slow release) of CRF was added to 500 ml distilled water in separate flasks and stirred continuously at a low speed during measurement period. A nitrate electrode and a reference electrode were set in the solution. The nitrate electrode responded to the increase in nitrate concentration caused by nitrate release from he CRFs. The response analog signal from the nitrate sensor was input to a 16-bit analog/digital converter with 1-minute interval for each measurement. The results indicated that 9% of the nitrate from the fast CRF (2- to 3-month longevity) was released in 10 hours. About 11.5% of the nitrate from the slow CRF (8- to 9-month longevity) was released in 260 hours. Based on the observed release rates, a 2- to 3-month longevity CRF will last about 111 hours in the stirred distilled water at room temperature. A CRF with 8 to 9 month longevity will last about 94.2 days. Even though field conditions are different from the experimental conditions, the real longevity of CRF in the fields may have to be further investigated. In the tropical southern Florida climate, the release rates of nutrients from CRFs are likely to be enhanced.
35
Peptu, Catalina, Marcel Popa, and Sophia G. Antimisiaris. "Release of Liposome-Encapsulated Calcein from Liposome Entrapping Gelatin-Carboxymethylcellulose Films: A Presentation of Different Possibilities." Journal of Nanoscience and Nanotechnology 8, no. 5 (2008): 2249–58. http://dx.doi.org/10.1166/jnn.2008.169.
Full textAbstract:
Liposome entrapment in films consisting of gelatin (GEL) or GEL/sodium carboxymethylcellulose (NaCMC) mixtures, as a method to alter drug release kinetics from polymeric films and/or incorporate sensitive bioactive molecules in solid films, was investigated. Bulk or thin complex (liposome trapping) films were formed by crosslinking (with glutaraldehyde) solutions of GEL or GEL/NaCMC in presence of calcein-encapsulating or rhodamine-labeled liposomes (Rho-Lip). Rho-Lip were observed by confocal microscopy to be homogenously distributed in the films. Calcein release from films was evaluated for periods up to 25 d, and it was found that several possibilities, concerning the release of the liposome-encapsulated molecule from the films, are offered; (i) Release can be sustained, if large liposomes are entrapped in the films. In this case the liposome-encapsulated molecules are released from the films only after they have been released from the vesicles, and the release can be controlled by modifying the film composition, the network density and/or the film geometry. (ii) Intact small unilamellar liposomes (SUV) can be released from the polymeric films depending on their swelling degree. The later can be controlled by modulating the film composition and amount of crosslinker. Film composition also affects the integrity of the film-entrapped liposomes during the crosslinking process, possibly due its effect on the density of the polymeric network of the film.
36
Naeimi, Shakiba, and Hossein Faghihian. "Controlled Release of Doxycycline by Magnetized Microporous MIL53(Fe); Focus on Magnetization and Drug Loading." Current Drug Delivery 16, no. 1 (2018): 42–50. http://dx.doi.org/10.2174/1567201815666180926120525.
Full textAbstract:
Background: In this research, MIL-53(Fe) was magnetized and the performance of the magnetized material as a drug delivery system for doxycycline was studied. Objectives: The experiments were designed to load the magnetic delivery compounds with different amount of the drug. Methods: The in vitro release rate of doxycycline from magnetic MIL-53(Fe) with different drug content into saline buffered fluid (SBF, pH=7.4) and phosphate buffered saline (PBS, pH=3) was then studied. Results: The results showed that the releasing process of the drug in PBS media achieved the equilibration within 48h with 98% of releasing efficiency, while the releasing process in SBF media (pH=7.4) was slower and the equilibrium was established within 264 h with the releasing efficiency of 95%. The amount of the released doxycycline from the samples with different drug content was measured at various time intervals. Conclusion: It was concluded that in PBS media after 75 h, 85, 95 and 98% of loaded doxycycline released, respectively, from the sample containing 22, 32 and 35% of the drug. In SBF media, the release was slower and after 350 h, 82, 91 and 95% of loaded doxycycline released from the samples, respectively, containing 22, 32 and 35 % of the drug. The results of this study indicated that by use of drugreleasing profile and selecting appropriate carrier dose, the released amount of the drug into the patient body can be controlled.
37
Anuchiracheewa, W., P. Pavasant, and Sorada Kanokpanont. "Gelatin/Fibroin Hydrogel for Controlled Release of Human Dentin Matrix Extract." Advanced Materials Research 506 (April 2012): 505–8. http://dx.doi.org/10.4028/www.scientific.net/amr.506.505.
Full textAbstract:
Dentin matrix extract (DME) was reported to induce differentiation of bone cell line MC3T3-E1, since it contained a number of growth factors. Human DME was prepared from human teeth milled under liquid nitrogen. The resulted powder was demineralized in 0.5M EDTA and the crude proteins were separated using dialysis. DME contained proteins with molecular weight in the range of 55-72 kDa and had Zeta-potential value at-10.53 ± 0.12 mV, and-13.53 ± 0.12 mV, in PBS (pH 7.5), and in deionized water (pH 5.5), respectively. Three types of hydrogel carriers were fabricated from gelatin and Thai silk fibroin (G:SF) at the weight ratio of 100:0, 70:30, and 50:50. Glutaraldehyde was used as crosslinker. The carriers had water absorption 90.43 ± 0.29 %, 87.73 ± 0.29 %, 86.60 ± 0.76 % by weight respectively.In vitrorelease experiment of DME from these carriers showed controlled-release mechanism. The G:SF 100:0 released the highest DME content within 48 h, while the G:SF 50:50 hardly released DME within 2 days. These results shows the G:SF system can be used for controlled-release for DME.
38
Nagella, Sivagangi Reddy, Soojeong Choi, Soo-Yong Park, et al. "Depolymerized Chitosan-g-[Poly(MMA-co-HEMA-cl-EGDMA)] Based Nanogels for Controlled Local Release of Bupivacaine." International Journal of Molecular Sciences 24, no. 22 (2023): 16470. http://dx.doi.org/10.3390/ijms242216470.
Full textAbstract:
This study is designed to formulate and characterize chitosan-based nanogels that provide the controlled delivery of anesthetic drugs, such as bupivacaine (BPV), for effective postoperative pain management over prolonged periods of time. Drug carriers of chitosan/poly (MMA-co-HEMA-cl-EGDMA) (CsPMH) nanogels were prepared by varying the composition of comonomers such as MMA, HEMA, and redox initiator CAN. The nanogels were then characterized using FTIR, TGA, SEM, and TEM. The CsPMH nanogels showed greater encapsulation efficiencies from 43.20–91.77%. Computational studies were also conducted to evaluate the interaction between the drug and CsPMH nanoparticles. Finally, BPV-loaded nanoparticles were used to examine their in vitro release behavior. At pH 7.4, all the drug carriers displayed the “n” value around 0.7, thus the BPV release follows anomalous diffusion. Drug carrier 7 demonstrated a steady and sustained release of BPV for approximately 24 h and released about 91% of BPV, following the K-P mechanism of drug release. On the other hand, drug carrier 6 exhibited controlled release for approximately 12 h and released only 62% of BPV.
39
Park, Seok, Min Kim, Seung-Ki Baek, Jung-Hwan Park, and Seong-O. Choi. "Spray-Formed Layered Polymer Microneedles for Controlled Biphasic Drug Delivery." Polymers 11, no. 2 (2019): 369. http://dx.doi.org/10.3390/polym11020369.
Full textAbstract:
In this study we present polymeric microneedles composed of multiple layers to control drug release kinetics. Layered microneedles were fabricated by spraying poly(lactic-co-glycolic acid) (PLGA) and polyvinylpyrrolidone (PVP) in sequence, and were characterized by mechanical testing and ex vivo skin insertion tests. The compression test demonstrated that no noticeable layer separation occurred, indicating good adhesion between PLGA and PVP layers. Histological examination confirmed that the microneedles were successfully inserted into the skin and indicated biphasic release of dyes incorporated within microneedle matrices. Structural changes of a model protein drug, bovine serum albumin (BSA), in PLGA and PVP matrices were examined by circular dichroism (CD) and fluorescence spectroscopy. The results showed that the tertiary structure of BSA was well maintained in both PLGA and PVP layers while the secondary structures were slightly changed during microneedle fabrication. In vitro release studies showed that over 60% of BSA in the PLGA layer was released within 1 h, followed by continuous slow release over the course of the experiments (7 days), while BSA in the PVP layer was completely released within 0.5 h. The initial burst of BSA from PLGA was further controlled by depositing a blank PLGA layer prior to forming the PLGA layer containing BSA. The blank PLGA layer acted as a diffusion barrier, resulting in a reduced initial burst. The formation of the PLGA diffusion barrier was visualized using confocal microscopy. Our results suggest that the spray-formed multilayer microneedles could be an attractive transdermal drug delivery system that is capable of modulating a drug release profile.
40
Yang, Shun, Najun Li, Zhuang Liu, et al. "Amphiphilic copolymer coated upconversion nanoparticles for near-infrared light-triggered dual anticancer treatment." Nanoscale 6, no. 24 (2014): 14903–10. http://dx.doi.org/10.1039/c4nr05305b.
Full textAbstract:
The light-triggered controlled release of anticancer drugs accompanied with NIR-responsive photodynamic therapy was performed via a self-assembly process. Under 980 nm laser, the cancer cells could be effectively inhibited by released drugs and singlet oxygen simultaneously.
41
Sánchez-Orozco, Jorge Luis, Héctor Iván Meléndez-Ortiz, Bertha Alicia Puente-Urbina, Oliverio Santiago Rodríguez-Fernández, Antonia Martínez-Luévanos, and Luis Alfonso García-Cerda. "Synthesis and Characterization of a pH- and Temperature-Sensitive Fe3O4-SiO2-Poly(NVCL-co-MAA) Nanocomposite for Controlled Delivery of Doxorubicin Anticancer Drug." Polymers 15, no. 4 (2023): 968. http://dx.doi.org/10.3390/polym15040968.
Full textAbstract:
This work reports the synthesis, characterization, and in vitro release studies of pH- and temperature-sensitive Fe3O4-SiO2-poly(NVCL-co-MAA) nanocomposite. Fe3O4 nanoparticles were prepared by chemical coprecipitation, coated with SiO2 by the Stöber method, and functionalized with vinyl groups. The copolymer poly(N-vinylcaprolactam-co-methacrylic acid) (poly(NVCL-co-MAA)) was grafted onto the functionalized Fe3O4-SiO2 nanoparticles by free radical polymerization. XRD, FTIR, TGA, VSM, and TEM techniques were performed to characterize the nanocomposite. The release behavior of Doxorubicin (DOX) loaded in the nanocomposite at pH 5.8 and 7.4, and two temperatures, 25 and 37 °C, was studied. According to the release studies, approximately 55% of DOX is released in 72 h at pH 7.4, regardless of temperature. At pH 5.8, 78% of DOX was released in 48 h at 25 °C, and when increasing the temperature to 37 °C, more than 95 % of DOX was released in 24 h. The DOX release data treated with Zero-order, first-order, Higuchi, and Korsmeyer–Peppas models showed that Higuchi’s model best fits the data, indicating that the DOX is released by diffusion. The findings suggest that the synthesized nanocomposite may be useful as a DOX carrier in biomedical applications.
42
Nalbadis, Anastasios, Marie-Luise Trutschel, Henrike Lucas, Jana Luetzkendorf, Annette Meister, and Karsten Mäder. "Selection and Incorporation of siRNA Carrying Non-Viral Vector for Sustained Delivery from Gellan Gum Hydrogels." Pharmaceutics 13, no. 10 (2021): 1546. http://dx.doi.org/10.3390/pharmaceutics13101546.
Full textAbstract:
The local controlled release of siRNA is an attractive and rational strategy to enhance and extend the effectiveness of gene therapy. Since naked and unmodified siRNA has a limited cell uptake and knockdown efficiency, the complexation of siRNA with non-viral carriers is often necessary for the delivery of bioactive RNA. We evaluated the performance of three different non-viral siRNA carriers, including DOTAP lipoplexes (DL), chitosan polyplexes (CP), and solid lipid complexes (SLC). The physicochemical properties of the siRNA-nanocarriers were characterized by dynamic light scattering and gel electrophoresis. After in vitro characterization, the carrier with the most appropriate properties was found to be the DL suspension, which was subsequently loaded into a gellan gum hydrogel matrix and examined for its drug load, stability, and homogeneity. The hydrogels microstructure was investigated by rheology to assess the impact of the rheological properties on the release of the siRNA nanocarriers. A controlled release of complexed siRNA over 60 days in vitro was observed. By comparing the results from fluorescence imaging with data received from HPLC measurements, fluorescence imaging was found to be an appropriate tool to measure the release of siRNA complexes. Finally, the bioactivity of the siRNA released from hydrogel was tested and compared to free DL for its ability to knockdown the GFP expression in a DLD1 colon cancer cell model. The results indicate controlled release properties and activity of the released siRNA. In conclusion, the developed formulation is a promising system to provide local controlled release of siRNA over several weeks.
43
TUNA, ŞEYMA, ASLI BEYLER-ÇIĞIL, and SERAP DEMIR. ""PREPARATION AND CHARACTERIZATION OF HYBRID NANOMATERIALS CONTAINING MAGNETIC FE3O4 NANOPARTICLES AS DRUG DELIVERY SYSTEM "." Cellulose Chemistry and Technology 56, no. 7-8 (2022): 795–805. http://dx.doi.org/10.35812/cellulosechemtechnol.2022.56.71.
Full textAbstract:
In this study, magnetic Fe3O4 nanoparticles were synthesized and the magnetic surfaces of the nanoparticles were modified with thiol groups. The chitosan polymer was modified with allyl groups and then bound to magnetic nanoparticles by the thiol-en click reaction. The drugs paclitaxel (PTX) and doxorubicin (DOX) were loaded separately and together into this prepared hybrid material, and then drug releases from the hybrid material were studied. The aim of this paper is to present the results on the controlled release of DOX and PPT cancer drugs from chitosan-Fe3O4 nanoparticles at two different pH values (5.0 and 7.4). PTX was effectively loaded into chitosan-Fe3O4 nanoparticles and slowly released up to 72.66% at pH 5 and 41.45% at pH 7.4 after 48 hours. DOX was effectively loaded into chitosan-Fe3O4 nanoparticles and slowly released up to 30.5% at pH 5 and 23.3% at pH 7.4 after 48 hours.
44
Passarelli, Gianna V., Patricio Doldan, Camila Metz-Zumaran, Yagmur Keser, Steeve Boulant, and Megan L. Stanifer. "Rotavirus Spreads in a Spatially Controlled Manner." Cells 14, no. 4 (2025): 313. https://doi.org/10.3390/cells14040313.
Full textAbstract:
Rotavirus is an enteric virus that leads to 200,000 deaths worldwide every year. The live-cell imaging evaluating rotavirus infection of MA104 cells revealed that rotavirus replication and spread occurs in a spatially controlled manner. Specifically, following initial rotavirus infection, the infected cells die, and the second round of infection occurs in the restricted area surrounding the initially infected cell. Interestingly, we found that the time required to establish the secondary infection is shorter compared to the time required for the initial infection. To determine if this increase in the kinetic of secondary infection was due to the early release of viruses or priming of the cells that are infected during the secondary infection, we used a combination of live-cell microscopy, trypsin neutralization assays, and the pharmacological inhibition of calcium signaling. Together, our results show that the second round of infection required rotavirus to be released and accessible to extracellular proteases. In addition, we found that the calcium wave induced upon rotavirus infection was critical for initial infection but did not play a role in the establishment of a secondary infection. Finally, we uncovered that high viral titers released from the initial infection were sufficient to accelerate the rate of the secondary infection.
45
Alderman, Stephen C., Darrin L. Walenta, Philip B. Hamm, Ruth C. Martin, Jeremiah Dung, and Evsey Kosman. "Afternoon Ascospore Release in Claviceps purpurea Optimizes Perennial Ryegrass Infection." Plant Disease 99, no. 10 (2015): 1410–15. http://dx.doi.org/10.1094/pdis-09-14-0978-re.
Full textAbstract:
In Kentucky bluegrass (Poa pratensis), Claviceps purpurea, the causal agent of ergot, typically releases ascospores during the early-morning hours, between about midnight and 10:00 a.m., corresponding to time of flowering, when the unfertilized ovaries are most susceptible to infection. During aeromycology studies of C. purpurea in perennial ryegrass (Lolium perenne) in northeastern Oregon during 2008 to 2010 and 2013, a strain of C. purpurea was found that released ascospores in the afternoon, coinciding with flowering in perennial ryegrass. Under controlled environmental conditions, sclerotia from perennial ryegrass and Kentucky bluegrass released spores in the afternoon and morning, respectively, consistent with timing of spore release under field conditions. Internal transcribed spacer (ITS) sequences of single sclerotial isolates from Kentucky bluegrass and perennial ryegrass were consistent with C. purpurea, although minor variations in ITS sequences among isolates were noted. Differences between Kentucky bluegrass and perennial ryegrass isolates were observed in random amplified polymorphic DNA. Evidence is provided for adaptation of C. purpurea to perennial ryegrass by means of delayed spore release that coincides with afternoon flowering in perennial ryegrass.
46
Qin, Yan Ping, Lin Tao Dai, Zhi Jie Kong, Ya Jing Wang, Ai Min Huang, and Lin Ma. "Organobentonites for Controlled Release of Diazinon." Advanced Materials Research 941-944 (June 2014): 975–80. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.975.
Full textAbstract:
Organobentonites with dodecyltrimethylammonium chloride (DTMA) and hexadecyl trimethyl ammonium chloride (HTMA) were prepared and used as carrier of diazinon, with purpose to provide controlled release properties to the formulation containing diazinon. The structure of organobentonites was characterized by FTIR and XRD and the sorption towards diazinon was investigated, to reveal the effects of organobentonites on the release of diazinon. It was showed that organobentonites with quaternary alkylammonium were of excellent sorption capacity towards diazinon, in which hydrophobic interaction played a key roll. An enhancement of sorption could be achieved by increasing the alkyl chain length and the loading level of modifying agent. The release of diazinon was greatly reduced by organobentonites. The time taken for 50% of active ingredient to be released, T50, from organobentonites with DTMA loading of 75, 100 and 125% of the cation exchange capacity were 45.9, 40.2 and 38.0 times of the value for the formulation without organobentonites, respectively. Those for the release from organobentonites with HTMA of the same loading level were 73.2, 63.2 and 52.1 times. The difference of diazinon release may be related to the change in the structure of organobentonites and the interaction with diazinon. An increase in loading level of quaternary ammonium could produce a faster release of diazinon, while the extension of the alkyl chain slowed down the release.
47
Cao, Yang, Bochu Wang, Yazhou Wang, and Deshuai Lou. "Polymer-controlled core–shell nanoparticles: a novel strategy for sequential drug release." RSC Adv. 4, no. 57 (2014): 30430–39. http://dx.doi.org/10.1039/c4ra03610g.
Full textAbstract:
Immiscible and miscible liquids were utilized to fabricate PVP/PLGA and PCL/PLGA nanoparticles with a distinct core–shell structure by coaxial electrospray. Two different sequential drug release profiles from different nanoparticles were observed. The melanoma cells and endothelial cells can be sequentially targeted and killed by therapeutic agents released from nanoparticles.
48
Hamidi, Rashidah Mohamed, Ahmer Ali Siyal, Tero Luukkonen, Rashid M. Shamsuddin, and Muhammad Moniruzzaman. "Fly ash geopolymer as a coating material for controlled-release fertilizer based on granulated urea." RSC Advances 12, no. 51 (2022): 33187–99. http://dx.doi.org/10.1039/d2ra06056f.
Full textAbstract:
The effect of fly ash particle size and solid to liquid ratio on the performance of geopolymer as a coating material for controlled release urea was investigated. Geopolymer coated urea completely released in 132 minutes in water and 15 days in soil.
49
H., U. Itodo, A. Nnamonu L., and A. Wuana R. "Green Synthesis of Copper Chitosan Nanoparticles for Controlled Release of Pendimethalin." Asian Journal of Chemical Sciences 2, no. 3 (2017): 1–10. https://doi.org/10.9734/AJOCS/2017/32937.
Full textAbstract:
<strong>Aim:</strong> In a bid to reduce the environmental impact from the use of herbicides, chitosan was used for the synthesis of copper nanoparticles and the controlled release formulations (CRFs) of pendimethalin copper-chitosan nanoparticles (Pend-CuCtsNPs). <strong>Methodology:</strong> The synthesized nanoparticles were characterized using UV-visible spectroscopy, Fourier Transform Infra-Red (FT-IR), Powder X-ray diffraction (PXRD), Transmission electron microscopy (TEM) and Energy-dispersive x-ray (EDX). Average crystalline size of the nanoparticles was estimated from the Debye- Scherrer’s equation. <strong>Results:</strong> The yield of the synthesized CuCtsNPs increased linearly with the weight of the starting material with percentage yield of 93.8% for the 0.8% chitosan matrix. Encapsulation efficiency of the nano-formulation fell within 57.5 and 92.7%. The aqueous release studies of Pend-CuCtsNPs, monitored for 96 hours in a batch release mode were carried out in three different pH media and percentage herbicide released for all composites showed that the release in pH 5.5 (acidic) medium was higher and the lowest release was recorded for pH 7.0 (neutral) medium. There was a statistically significant difference between pH groups and time as determined by UNIANOVA (<em>p</em> < .005). <strong>Conclusion:</strong> Findings from this study however shows that there is a controlled release of pendimethalin using nano-formulation over the conventional herbicide application.
50
Jahn, Peter, James G. Ross, Vanessa Mander, and Laura E. Molles. "Post-translocation movements and ranging behaviour of roroa (great spotted kiwi, Apteryx maxima)." Notornis 69, no. 3 (2022): 135. https://doi.org/10.63172/629027twlhsn.
Full textAbstract:
Translocations are increasingly used in kiwi (Apteryx spp.) conservation management, and their outcome is largely influenced by post-release dispersal and survival. A translocation of roroa (great spotted kiwi, A. maxima) to the Nina Valley, near Lake Summer Forest Park, is the first reintroduction of the Arthur’s Pass roroa population. In 2015, eight wild-caught adults were translocated from Arthur’s Pass National Park, following the release of ten captive-hatched subadults during 2011–13. We monitored the translocated kiwi by radio telemetry during 2015–17. Dispersal was highly variable among the released wild birds. The straight-line distance from the release site to the last recorded location ranged 0.5–10.3 km. Seven of the wild birds remained in the Nina Valley and covered an area up to 1,700 ha (95% utilisation distribution). Releasing the wild birds had no measurable impact on the ranging behaviour of previously released subadults. The current population founder group comprises a maximum of 13 unrelated individuals, and therefore further releases are necessary for a genetically viable population. Additionally, expansion of the pest-controlled area is crucial for the long-term persistence of the reintroduced population in the Nina Valley.