Literatura científica selecionada sobre o tema "PLGA"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Consulte a lista de atuais artigos, livros, teses, anais de congressos e outras fontes científicas relevantes para o tema "PLGA".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Artigos de revistas sobre o assunto "PLGA"
1
Li, Qing, Yiling Zhang, Jingbing Li, Hao Wang, Hui Lu, Honghao Fan e Gang Zheng. "Stimulatory effects of poly-para-dioxanone, poly L-lactic acid, polycaprolactone, and poly(lactic-co-glycolic acid)/PLLA in rats". Materials Express 9, n.º 8 (1 de novembro de 2019): 962–69. http://dx.doi.org/10.1166/mex.2019.1582.
Texto completo da fonteResumo:
Numerous fillers are increasingly used for augmenting volume loss and ameliorating facial wrinkles. Collagen stimulants are the most recent next-generation dermal fillers capable of inducing neocollagenesis. To investigate biophysical characteristics, the safety and efficacy of the newly developed combination, poly(L-lactide) or polyl-lactic acid (PLLA) and poly(lactide-co-glycolide) (PLGA), were compared with those of poly-para-dioxanone (PPDO), poly-l-lactic acid (PLLA), and polycaprolactone (PCL) fillers. PPDO, PLLA, PCL, or PLGA/PLLA was injected into the dorsal skin of 8-week-old rats. Tissue samples were obtained 0, 2, and 4 weeks post treatment for Sirius Red-staining, polarized light microscopy, enzyme-linked immunosorbent assay (ELISA), real-time reverse transcription PCR (qRT-PCR), and western blotting. The MagBeads Total RNA Extraction Kit was used to isolate total cell RNA. The PLGA/PLLA filler demonstrated similar neocollagenesis and inflammatory response as other collagen stimulants, and showed better biodegradability than PPDO, PLLA and PCL fillers. Our data suggest that the newly developed collagen-stimulating PLGA/PLLA filler may be a safe and effective option for correcting volume loss and rejuvenating photoaging skin.
2
Jeong, Jieun, Sangsoo Yoon, Xin Yang e Young Jun Kim. "Super-Tough and Biodegradable Poly(lactide-co-glycolide) (PLGA) Transparent Thin Films Toughened by Star-Shaped PCL-b-PDLA Plasticizers". Polymers 15, n.º 12 (8 de junho de 2023): 2617. http://dx.doi.org/10.3390/polym15122617.
Texto completo da fonteResumo:
To obtain fully degradable and super-tough poly(lactide-co-glycolide) (PLGA) blends, biodegradable star-shaped PCL-b-PDLA plasticizers were synthesized using natural originated xylitol as initiator. These plasticizers were blended with PLGA to prepare transparent thin films. Effects of added star-shaped PCL-b-PDLA plasticizers on mechanical, morphological, and thermodynamic properties of PLGA/star-shaped PCL-b-PDLA blends were investigated. The stereocomplexation strong cross-linked network between PLLA segment and PDLA segment effectively enhanced interfacial adhesion between star-shaped PCL-b-PDLA plasticizers and PLGA matrix. With only 0.5 wt% addition of star-shaped PCL-b-PDLA (Mn = 5000 g/mol), elongation at break of the PLGA blend reached approximately 248%, without any considerable sacrifice over excellent mechanical strength and modulus of PLGA.
3
Taşkor Önel, Gülce. "Synthesis of L-ornithine- and L-glutamine-Linked PLGAs as Biodegradable Polymers". Polymers 15, n.º 19 (5 de outubro de 2023): 3998. http://dx.doi.org/10.3390/polym15193998.
Texto completo da fonteResumo:
L-ornithine and L-glutamine are amino acids used for ammonia and nitrogen transport in the human body. Novel biodegradable synthetic poly(lactic-co-glycolic acid) derivatives were synthesized via conjugation with L-ornithine or L-glutamine, which were selected due to their biological importance. L-ornithine or L-glutamine was integrated into a PLGA polymer with EDC coupling reactions as a structure developer after the synthesis of PLGA via the polycondensation and ring-opening polymerization of lactide and glycolide. The chemical, thermal, and degradation property–structure relationships of PLGA, PLGA-L-ornithine, and PLGA-L-glutamine were identified. The conjugation between PLGA and the amino acid was confirmed through observation of an increase in the number of carbonyl carbons in the range of 170–160 ppm in the 13C NMR spectrum and the signal of the amide carbonyl vibration at about 1698 cm−1 in the FTIR spectrum. The developed PLGA-L-ornithine and PLGA-L-glutamine derivatives were thermally stable and energetic materials. In addition, PLGA-L-ornithine and PLGA-L-glutamine, with their unique hydrophilic properties, had faster degradation times than PLGA in terms of surface-type erosion, which covers their requirements. L-ornithine- and L-glutamine-linked PLGAs are potential candidates for development into biodegradable PLGA-derived biopolymers that can be used as raw materials for biomaterials.
4
Denning, G. M. "IL-4 and IFN-gamma synergistically increase total polymeric IgA receptor levels in human intestinal epithelial cells. Role of protein tyrosine kinases." Journal of Immunology 156, n.º 12 (15 de junho de 1996): 4807–14. http://dx.doi.org/10.4049/jimmunol.156.12.4807.
Texto completo da fonteResumo:
Abstract IL-4 and IFN-gamma increase release of secretory component (SC), the polymeric IgA (plgA)-binding segment of the plgA receptor (plgAR), by the human intestinal epithelial cell line HT29. Moreover, these two cytokines synergistically increase plgA binding and cell surface staining for the receptor. To understand better the mechanism by which these cytokines regulate plgAR, we did quantitative immunoblotting using Abs against secretory component. We found that synergy occurs at the level of total cellular plgAR. Additionally, time course studies indicated that maximal receptor levels required >24-h incubation, that reaching maximal levels required at least 18 h of cytokine treatment, and that receptor levels remained elevated as long as cytokines were present. Conversely, if cytokines were removed, then cellular plgAR levels decreased with an approximate t1/2 of 20 h. Finally, synergy required the simultaneous presence of both cytokines throughout the treatment period. Direct measurement of second messengers and inhibitor studies suggest that Ca2+, cAMP, protein kinase A, and protein kinase C do not play major roles in regulating cellular plgAR levels by either cytokine, and do not contribute to the mechanism of synergy. In contrast, protein tyrosine kinase inhibitors potently inhibited all cytokine-dependent increases in total cellular plgAR. These results suggest that IL-4 and IFN-gamma increase cellular plgAR levels in HT29 cells predominantly by activating protein tyrosine kinase-dependent signaling pathways.
5
Rezende, Camila A. de, e Eliana Ap R. Duek. "Blendas de poli (ácido lático-co-ácido glicólico)/ poli (ácido lático): degradação in vitro". Polímeros 13, n.º 1 (janeiro de 2003): 36–44. http://dx.doi.org/10.1590/s0104-14282003000100009.
Texto completo da fonteResumo:
Placas de copolímero de poli(ácido lactico-co-glicólico) têm sido produzidas e usadas como implantes que degradam e são absorvidos pelo organismo. Implantes que podem ser absorvidos apresentam vantagens em relação aos implantes metálicos. Nesse trabalho, foram obtidas placas a partir de blendas de poli(ácido lactico-co-glicólico)/ poli(ácido lático), (PLGA/PLLA) e caracterizadas durante o processo de degradação in vitro. Verificou-se que as blendas são imiscíveis e a estabilidade térmica das mesmas aumenta com a proporção de PLLA. O grau de cristalinidade também aumenta com a proporção de PLLA na amostra e com o tempo de degradação. Além disso, verificou-se que o PLGA degrada rapidamente e sua presença e quantidade modifica nitidamente a morfologia das blendas.
6
Cardoso, M. Margarida, Inês N. Peca, Telma Lopes, Rui Gardner e A. Bicho. "Double-Walled Poly-(D,L-lactide-co-glycolide) (PLGA) and Poly(L-lactide) (PLLA) Nanoparticles for the Sustained Release of Doxorubicin". Polymers 13, n.º 19 (23 de setembro de 2021): 3230. http://dx.doi.org/10.3390/polym13193230.
Texto completo da fonteResumo:
Double-walled nanoparticles (DWNPs), containing doxorubicin as a model drug, were produced using poly-(D,L-lactide-co-glycolide) (PLGA) and poly(L-lactide) (PLLA) by the solvent evaporation technique. Double-walled microparticles containing doxorubicin were also produced to make possible the examination of the inner morphology and drug distribution using optical and fluorescence microscopy. The produced microparticles present a double-walled structure with doxorubicin solubilized in the PLGA-rich phase. The DWNPs produced present very low initial burst values and a sustained DOX release for at least 90 days with release rates decreasing with the increase in the PLLA amount. Zero-order release kinetics were obtained after day 15. The results support that the PLLA layer acts as a rate control barrier and that the diffusion of doxorubicin from the drug-loaded inner PLGA core can be retarded by an increase in the thickness of the unloaded outer layer. The unloaded double-walled nanoparticles produced were used in in vitro tests with CHO cells and demonstrate that they are nontoxic, while the double-walled nanoparticles loaded with doxorubicin caused a great cellular viability and decreased when tested in vitro.
7
K., Prakash Raj, Kathiresan K. e Pandian P. "A Review on Poly-Lactic-Co-Glycolic Acid as a Unique Carrier for Controlled and Targeted Delivery Drugs". Journal of Evolution of Medical and Dental Sciences 10, n.º 27 (5 de julho de 2021): 2034–41. http://dx.doi.org/10.14260/jemds/2021/416.
Texto completo da fonteResumo:
In regulated and targeted drug distribution, biodegradable polymers have played a significant portion. Poly-lactic-co-glycolic acid (PLGA) has been an important desirable polymer in tissue engineering to meet a new drug delivery system. PLGAs, show a broad spectrum of erosion cycles and have tuning mechanical characteristics. Poly-lactic-co-glycolic acid (PLGA) has been the most successful polymeric biomaterial for use in controlled drug delivery systems. PLGA has been extensively studied, in particular, in the production of equipment for controlled distribution in industrial and research applications of small molecules, protein, and other macromolecules. PLGA is biocompatible and biodegradable, exhibits a wide range of erosion times, has tunable mechanical properties and most importantly, is a FDA approved polymer. PLGA has many properties such as controlled and sustained release, low cancerinducing, long-standing biomedical applications, biocompatibility with tissues and cells, and prolonged residence time. It is otherwise called as 'Smart Polymer' because improvements are fragile to conduct PLGA that has been widely examined in industrial and academic applications to produce instruments for the target delivery of tiny molecular drugs, proteins, and other large molecules. An introduction about the chemistry, physicochemical properties, manufacturing techniques of the devices, toxicity, and the reason influencing their decrease and release of the drug was given in the present study. Mathematical modelling is a useful tool for identifying, characterizing, and predicting the mechanisms of controlled release. Mathematical modelling applied against the target from PLGA – the devices has been clarified by discussing in the review, by explaining the underlying mathematical models and how this is used. KEY WORDS Biodegradable Polymers, PLGA, Biodegradability, Macromolecules
8
Pek, Y. Shona, Pemakorn Pitukmanorom e Jackie Y. Ying. "Sustained release of bupivacaine for post-surgical pain relief using core–shell microspheres". J. Mater. Chem. B 2, n.º 46 (2014): 8194–200. http://dx.doi.org/10.1039/c4tb00948g.
Texto completo da fonte
9
Dutta, D., C. Fauer, K. Hickey, M. Salifu e S. E. Stabenfeldt. "Tunable delayed controlled release profile from layered polymeric microparticles". Journal of Materials Chemistry B 5, n.º 23 (2017): 4487–98. http://dx.doi.org/10.1039/c7tb00138j.
Texto completo da fonte
10
Wen, He, Litian Qu, Yu Zhang, Beilei Xu, Shiqi Ling, Xiaochun Liu, Yang Luo, Da Huo, Wei Li e Xu Yao. "A Dendritic Cells-Targeting Nano-Vaccine by Coupling Polylactic-Co-Glycolic Acid-Encapsulated Allergen with Mannan Induces Regulatory T Cells". International Archives of Allergy and Immunology 182, n.º 9 (2021): 777–87. http://dx.doi.org/10.1159/000512872.
Texto completo da fonteResumo:
<b><i>Background:</i></b> The efficacy of allergen-specific immunotherapy (AIT) is mainly depended on the tolerogenic immune responses elicited. Properly conjugated nano-vaccine has the advantages of both specific targeting and continuous and on-demand release of allergen. <b><i>Objectives:</i></b> The aim of this study is to investigate the effects of a dendritic cells (DCs)-targeting nano-vaccine for AIT. <b><i>Methods:</i></b> The nano-vaccine was produced by coupling polylactic-co-glycolic acid (PLGA)-encapsulated ovalbumin (OVA) with mannan. Allergen capture, human monocytes-derived DCs (hMoDCs) activation, and T cells responses were assessed by flow cytometry, confocal microscopy, quantitative real-time PCR, ELISA, and Cytometric Bead Array. Balb/c mice were immunized with the nano-vaccines, and the immune responses were analyzed. <b><i>Results:</i></b> OVA-PLGA nanoparticle (NP) displayed favorable safety profile. OVA-mannan-PLGA NP was captured more efficiently by hMoDCs than OVA-PLGA NP, which was mediated mainly through DC-specific intercellular adhesion molecule 3-grabbing nonintegrin. A tolerogenic phenotype of hMoDCs was induced by OVA-mannan-PLGA NP, but not OVA-PLGA NP, and increased number of regulatory T (Treg) cells was generated subsequently in in vitro coculture. Immunization of Balb/c mice with OVA-mannan-PLGA NP resulted in lower serum level of OVA-specific immunoglobulins and less production of pro-inflammatory cytokines in splenocytes culture than the mice immunized with OVA-PLAG NP, PLGA NP, or OVA, while the number of splenic Treg cells was higher in OVA-mannan-PLGA group than in other groups. Moreover, preimmunization with OVA-mannan-PLGA NP significantly inhibited the Th2 immune response induced by OVA sensitization. <b><i>Conclusions:</i></b> The biocompatible PLGA-encapsulated OVA coupling with mannan has augmented ability for tolerance induction and could be developed as a novel vaccine for AIT.
Teses / dissertações sobre o assunto "PLGA"
1
Moura, Renata Kely de Paulo. "Avaliação in vitro das características de liberação de indometacina a partir de dispositivos oculares implantáveis". Universidade Federal da Paraíba, 2010. http://tede.biblioteca.ufpb.br:8080/handle/tede/6857.
Texto completo da fonteResumo:
Made available in DSpace on 2015-05-14T13:00:14Z (GMT). No. of bitstreams: 1
arquivototal.pdf: 1937147 bytes, checksum: c7c7a7218440d8aec73885dba794fe24 (MD5)
Previous issue date: 2010-08-31Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The anatomy and physiology of the eye, together with its protective barriers represent challenges to effective ocular drug delivery systems. The pharmacological treatment of eye diseases had been limited to conventional drug formulations, which are not satisfactory for diseases affecting the posterior segment of the eye. The delivery of therapeutic doses at tissues from the posterior segment in order to minimize adverse systemic and regional effects is the main goal in the treatment of ocular diseases. With this aim, several studies have been conducted to develop new ocular drug delivery systems, such as those involving ocular implants. These implants are prepared using a variety of different polymers that can be either biodegradable or non-biodegradable. Polymers derived from lactic and glycolic acid have revealed to be promising materials for the formulation of ocular implants, mainly due to their biocompatibility and biodegradability. In this study, two different biodegradable indomethacin implants formulated based on a copolymer of lactic/glicolic acid (PLGA 50:50) and D,L-lactic acid (D,L-PLA) were characterized by differential scanning calorimetry (DSC), in vitro release using dissolution apparatus and scleral diffusion (from rabit´s eye) using Franz chambers. The study was done in collaboration with 3T Biopolymers (São Paulo, Brazil) that provided samples of the polymers and implants for analyses. The results of the validation of the HPLC method for indomethacin quantification were within the limits set forth by Brazilian legislation (RE 899, 2003, ANVISA). The results of DSC analysis revealed absence of any evidence of physico-chemical interactions between the drug and polymer. The suppression of the indomethacin melting peak is probably due to changes from the crystalline to the amorphous state of the drug following lyophilization or by dilution effects. Preliminary in vitro release data revealed a triphasic profile for indomethacin release from the PLGA-based implants and a biphasic one for the PLA implants. The implants formulated with PLGA promoted a faster release of indomethacin (103.64%) compared with implants formulated with PLA (49.9%) during the thirty days of the experiment. The release profile of indomethacin was determined by the rate of degradation of polymers, which also determined the scleral diffusion of indomethacin from PLGA and PLA (1.7 x 10-5 cm / s and 0.24 x 10-5 cm / s, respectively). The scleral diffusion experiments using Franz difusion chambers have shown that the rabit sclera is permeable to indomethacin and polarized light microscopy revealed that the structure of the scleral collagen fibers were not significantly altered during the diffusion experiments. The drug-release systems studied were able to release indomethacin in a sustained fashion, serving as a model for the formulation of indomethacin implants that could be used in the future for the treatment of ocular diseases such as the cystoid macular edema.
A anatomia e fisiologia do olho e suas barreiras protetoras representam um desafio para o desenvolvimento de sistemas de transporte de drogas oftálmicas efetivos. O tratamento farmacológico de doenças oculares tem se limitado às formas convencionais de administração que não são satisfatórias para o tratamento de doenças que acometem o segmento posterior do bulbo do olho. O transporte de doses terapêuticas para os tecidos do segmento posterior do olho, que minimize os efeitos colaterais sistêmicos e locais, é o principal objetivo no tratamento de doenças oculares. Visando atingir este objetivo, estudos têm sido feitos no sentido de desenvolver novos sistemas de liberação de fármacos para o olho, entre estes estão os implantes. Esses implantes são preparados a partir de diferentes polímeros, os quais podem ser biodegradáveis ou não biodegradáveis. Os polímeros derivados dos ácidos lático e glicólico têm se revelado bastante promissores devido, principalmente, às suas características de biocompatibilidade e biodegradabilidade. Neste trabalho, dois diferentes implantes de indometacina formulados a partir do copolímero ácido lático / ácido glicólico (PLGA 50:50) e do polímero derivado do ácido D,L-lático (PLA), através de liofilização da mistura polímero-fármaco, foram fornecidos pela empresa 3T Biopolímeros (São Paulo - SP) e avaliados através de DSC, estudos de liberação in vitro usando aparato de dissolução e estudos de difusão através de esclera de coelho utilizando câmaras de Franz. Os resultados da validação do método CLAE para quantificação da indometacina apresentaram-se dentro dos limites estabelecidos pela legislação brasileira (Resolução RE 899, 2003, ANVISA). As análises de DSC mostraram a ausência aparente de interações químicas e físicas entre o fármaco e os polímeros, sendo sugerido que o desaparecimento do pico de fusão da indometacina tenha ocorrido pela amorfização do fármaco durante o processo de liofilização ou pela diluição do fármaco no polímero. Os estudos preliminares de liberação in vitro demonstraram um perfil trifásico para os implantes formulados com PLGA e um perfil bifásico para àqueles formulados com PLA. Os implantes formulados com PLGA promoveram uma liberação mais rápida da indometacina (103,64%) quando comparado com os implantes formulados com PLA (49,9%) durante os trinta dias de experimento. O perfil de liberação da indometacina foi determinado pela velocidade de degradação dos polímeros, que também determinou a difusão escleral da indometacina a partir do PLGA e do PLA (1,7 x 10-5 cm/s e 0,24 x 10-5 cm/s, respectivamente). Os estudos de difusão escleral mostraram que a esclera de coelho é permeável à indometacina e a microscopia de luz polarizada mostrou que a estrutura das fibras colágenas da esclera não foram significativamente alteradas durante o estudo de difusão nas câmaras de Franz. Os sistemas de liberação de fármacos avaliados foram capazes de liberar a indometacina de forma prolongada, servindo como um modelo para formulação de implantes de indometacina que podem ser futuramente utilizados para tratamento de doenças como edema macular cistóide.
2
Banerjee, Abhishek. "Functionalizable Biodegradable Polyesters for Drug Delivery Applications". University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1335240206.
Texto completo da fonte
3
Friedrich, Nadja. "Integration dermaler Fibroblasten in PLGA-Scaffolds". Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-130943.
Texto completo da fonteResumo:
Die Wundheilung stellt einen physiologischen Vorgang zur Regeneration zerstörten Gewebes dar. Der reibungslose Ablauf der Heilung wird durch ein komplexes Zusammenspiel von Zellen und extrazellulären Komponenten gewährleistet. Durch vielfältige Faktoren kann dieser fein abgestimmte Prozess zum Erliegen kommen, so dass eine chronische Wundheilungsstörung resultiert. Trotz zahlreicher Behandlungsmöglichkeiten chronischer Wunden bleibt jedoch die erfolgreiche Heilung oftmals aus. Die Anwendung von biodegradierbaren Materialen (Biomaterialien) in der Wundheilung wurde in den vergangenen Jahren intensiv erforscht und teilweise erfolgreich am Patienten eingesetzt. An dem Ziel, ein Biomaterial herzustellen, welches alle funktionellen und strukturellen Fähigkeiten gesunder menschlicher Haut mit sich bringt, wird jedoch nach wie vor gearbeitet. In verschiedenen Studien konnte die gute Verträglichkeit und Biodegradierbarkeit des Biopolymers PLGA, bestehend aus Lactat und Glycolsäure, bereits gezeigt werden. In der vorliegenden Dissertation wurden dreidimensionale (3D)-Gerüste (Scaffolds) aus PLGA hinsichtlich ihrer Wechselwirkungen mit humanen dermalen Fibroblasten (Fb) untersucht. Dermale Fb leisten einen entscheidenden Beitrag zur erfolgreichen Wundheilung, da sie unter der Einwirkung diverser Wachstumsfaktoren zur Migration ins Wundgebiet sowie zur Neusynthese und Reorganisation extrazellulärer Matrix (ECM) befähigt sind. In den Untersuchungen wurden grundlegende Kenntnisse zum Verhalten der Zellen bezüglich Proliferation sowie Synthese nativer ECM in den PLGA-Scaffolds gewonnen und das Migrationsverhalten der Fb in das Biomaterial untersucht. Dabei zeigte sich, dass dermale Fb in den PLGA-Scaffolds nicht nur proliferieren sondern auch einen ausgeprägten Matrixstoffwechsel aufweisen. Sie sind in der Lage, Kollagen und Hyaluronsäure, wichtige Bestandteile der ECM, abzulagern. Zudem konnte mit Hilfe der Arbeit der Einfluss von Wachstumsfaktoren sowohl auf relevante ECM-Komponenten im 3D-Kultursystem als auch auf das Migrationsverhalten der Fb in das Biomaterial verdeutlicht werden. Aus den Ergebnissen geht hervor, dass 3D-PLGA-Scaffolds geeignete Substrate zur Kultivierung dermaler Fb darstellen. Die zukünftig geplante Weiterentwicklung und Funktionalisierung dieses Biopolymers für den Einsatz in der Wundheilung scheint somit viel versprechend.
4
Bode, Corinna. "PLGA implants for ocular drug delivery". Thesis, Lille 2, 2019. http://www.theses.fr/2019LIL2S008.
Texto completo da fonteResumo:
Jusqu'à aujourd'hui, le traitement des maladies oculaires postérieures, telles que la dégénérescence maculaire liée à l'âge, la rétinopathie diabétique et l'uvéite, reste difficile. L'œil avec ses différentes barrières oculaires est bien protégé des agressions extérieures. Ces barrières réduisent également la biodisponibilité des médicaments pour le vitré. Après une administration topique, seule une quantité limitée (0,001 - 0,0004 %) permet d'atteindre le vitreux. Ceci est causé par exemple par une dilution des larmes et une faible perméabilité cornéenne du médicament. Après une administration systémique ou orale, les barrières hémato-oculaires empêchent le médicament d'entrer et seulement environ 2 % du médicament administré se trouve dans le vitré. Afin d'atteindre des concentrations thérapeutiques, une dose élevée doit être administrée, ce qui augmente le risque d'effets secondaires. La façon la plus efficace de traiter les maladies postérieures restent l'injection intravitréenne. Cependant, de petites molécules lipophiles comme la dexaméthasone peuvent facilement se diffuser à travers la rétine et les barrières oculaires et ont donc une demi-vie limitée de quelques heures seulement. Étant donné que de nombreuses maladies postérieures sont chroniques, une injection intravitréenne fréquente serait nécessaire. Chaque injection comporte des risques de décollement de la rétine, d'hémorragie et d'autres effets secondaires. Les implants biodégradables pour administration intravitréenne peuvent prolonger la libération du médicament et en diminuer les effets secondaires. PLGA est un polymère largement utilisé qui est biocompatible et biodégradable. Il peut également soutenir la libération du médicament de quelques jours à plusieurs mois. Dans cette étude, les implants de formation in situ (ISFI) et les implants préformés préparés par extrusion à chaude ont été étudié en profondeur. L'objectif de ce travail était (i) d'étudier l'impact du volume du rejet (ii) évaluer le comportement de libération, de gonflement et de dégradation des implants préformés préparés avec différentes charges de médicament et différents types de polymères, (iii) visualiser la libération de médicament et l'absorption d'eau des implants préformés et de l'ISFI en utilisant des médicaments modèles colorés et (iv) étudier l'effet des quantités variables des différents additifs sur les caractéristiques essentielles de l'ISFI. Ces informations peuvent aider à fabriquer des implants avec différents profils de libération. Nos études montrent que l'ISFI est assez robuste en ce qui concerne les différents volumes de l'humeur vitreuse que l'on peut rencontrer in vivo. Cependant, le poids moléculaire et la concentration du polymère ont une forte influence sur la morphologie et le gonflement de l'implant. Par conséquent, la dégradation et la libération du médicament sont affectées. Pour les implants préformés, le gonflement "orchestre" la libération du médicament. Au début, seule une quantité limitée d'eau peut se diffuser dans les implants. Ainsi, seules des quantités insignifiantes du médicament sont dissoutes et peuvent être libérées. Lorsque le PLGA commence à se dégrader, le polymère devient plus hydrophile et de plus grandes quantités d'eau peuvent pénétrer. Ce gonflement du polymère facilite la dissolution et la diffusion du médicament et déclenche la libération du médicament. Les études utilisant des médicaments modèles colorés corroborent le rôle de la pénétration de l'eau et de la dissolution du médicament pour les implants préformés. En ce qui concerne l'ISFI, il a visualisé l'importance de la concentration du polymère sur la structure interne de l'implant qui en résulte et par conséquent l'absorption d'eau et la libération du médicament. Le comportement de gonflement et la morphologie de l'ISFI pourraient également être modifiés de manière significative en utilisant différents additifs. L'effet global sur la libération du médicament a été limitéUntil today, the treatment of posterior eye diseases, such as age-related macular degeneration, diabetic retinopathy and uveitis, remains challenging. The eye with its different ocular barriers is well protected from external factors. Those barriers also reduce the bioavailability of drugs to the vitreous. After a topical administration, only a limited amount (0.001 – 0.0004 %) reaches the vitreous. This is caused by for example reflexive blinking, tear dilution and a low corneal permeability of the drug. After a systemic or oral administration, the blood-aqueous and the blood-retinal barrier hinder the drug from entering and only around 2 % of the administered drug is found in the vitreous. In order to reach therapeutic concentrations, a high dose has to be given which in turn increases the risk for systemic side effects. The most efficient way to treat posterior diseases remains the intravitreal injection. However, small lipophilic molecules like dexamethasone can easily diffuse through the retina and the blood-ocular barriers and, thus, have a limited half-life of just a few hours. Since many of the posterior diseases are chronic, a frequent intravitreal injection would be necessary. Every intravitreal injection bears the risks for retinal detachment, hemorrhage, and other side effects. Biodegradable implants for intravi-treal administration can prolong the drug release and in turn decrease the side effects. Poly(lac-tic-co-glycolic acid) (PLGA) is a widely used polymer that is biocompatible and biodegrada-ble. It can also sustain the drug release from a few days up to several months. In this study, in-situ forming implants (ISFI) and pre-formed implants prepared via hot melt extrusion were studied in depth. The aim of this work was (i) to study the impact of the volume of the release medium, polymer type and concentration as well as drug content of different ISFI, (ii) to eval-uate the drug release, swelling and degradation behavior of pre-formed implants prepared with different drug loadings and polymer types, (iii) to visualize the drug release and water uptake of ISFI and pre-formed implants using colored model drugs and (iv) to investigate the effect of varying amounts of different additives on key features of ISFI. This knowledge can help to manufacture implants with different release profiles. Our studies show that ISFI are rather ro-bust regarding different volumes of the vitreous humor that could be encountered in vivo. How-ever, the polymer molecular weight and polymer concentration have a strong influence on the morphology and swelling behavior of the implants. Consequently, the degradation and drug release are affected. For pre-formed implants the swelling “orchestrates” the drug release. In the beginning only limited amounts of water can diffuse into the implants. Thus, only insignif-icant amounts of the drug are dissolved and can be released. When the PLGA starts to degrade, the polymer becomes more hydrophilic and bigger amounts of water can penetrate. This poly-mer swelling facilitates drug dissolution and diffusion and initiates the drug release. The studies using colored model drugs corroborate the role of water penetration and drug dissolution for pre-formed implants. Concerning ISFI, it visualized the importance of the polymer concentra-tion on the resulting inner implant structure and consequently the water uptake and drug release. The swelling behavior and morphology of ISFI could also be significantly altered using differ-ent additives. The overall effect on the drug release was limited
5
Li, Zhongxuan. "Co-delivery of Two Growth Factors From Combined PLGA and PLLA/PCL Microsphere Scaffolds for Spinal Cord Injury Repairs". Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31200.
Texto completo da fonteResumo:
The purpose of this study is to demonstrate the effectiveness of spheres-in-tube structured scaffolds to sequentially deliver two biomolecules during two phases of tissue regeneration following spinal cord injury (SCI). Scaffolds were synthesized of a poly (lactic-co-glycolic acid) (PLGA) base combined with Poly (L-lactic acid) / Poly (ε-caprolactone) (PLLA/PCL) microspheres.
The scaffolds are constructed by leveraging the different solubilities of PLGA, PLLA and PCL in super critical carbon dioxide and ethyl acetate during fabrication processes. Microspheres can reduce the pore size and porosity of PLGA scaffolds; this enhances their mechanical strength and enables them to provide long-term treatment without collapse.
The release of the epidermal growth factor (EGF) and basic fibroblast growth factor (FGF-b) are being used to study the release profiles of the designed scaffolds. The analysis shows that FGF-b is released from high porosity PLGA base as the first delivery vehicle and completes the release in the first week. PLLA or PCL microspheres, having the property of sustainably delivering encapsulated EGF in 36 days, are used as the second drug delivery vehicle.
FGF-b released within the first week can mimic biomolecules used to protect the surviving neurons and promote the development of sprout axons. The sustained release of EGF from microspheres is used for long-term therapy to differentiate multipotent cells into determined types at the injury site.
The results demonstrate that these enhanced parameters along with the ability of sequential co-delivery of growth factors, make these designed scaffolds a promising candidate in SCI studies.
6
Mariño, Laura Victoria Español. "Aplicação da eletroforese capilar e cromatografia líquida de alta eficiência para a quantificação da dexametasona e diclofenaco em nanosuspensão". Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/9/9139/tde-28052015-084712/.
Texto completo da fonteResumo:
Os grandes desafios da medicina contemporânea destacam a necessidade de uma intensa pesquisa para desenvolver novos tratamentos para muitas doenças crônicas, tais como as reumáticas, que sejam efetivos, seguros e com qualidade. Uma das novas ferramentas para o desenvolvimento de novos medicamentos é a nanotecnologia, a qual nos últimos anos tem aumentado a sua aplicação na área farmacêutica contemplando um crescente otimismo acerca do seu potencial uso para obter melhores oportunidades de diagnóstico e de terapias mais eficazes. No presente trabalho foram encapsulados dois antiinflamatórios em sistemas nanoparticulados, nanoesferas de acido poli-láctico co-glicólico (PLGA), a técnica utilizada permitiu a encapsulação de compostos hidrofílicos e hidrofóbicos na mesma nanopartícula polimérica, diclofenaco de sódio (DS) e dexametasona (DX), respectivamente, obtendo nanopartículas com potencial para o tratamento de doenças inflamatórias crônicas. Para o desenvolvimento das nanoesferas se utilizou a técnica de emulsão/evaporação do solvente. As nanoesferas foram caraterizadas por microscopia eletrônica de varredura (SEM), microscopia eletrônica de transmissão (TEM), medição do pH, medição do tamanho de partícula, potencial zeta e polidisversividade e espectroscopia vibracional de infravermelho (IR). A eficiência de encapsulação (EE) dos fármacos (diclofenaco de sódio e dexametasona) nas nanoesferas foi realizada pelas técnicas analíticas, cromatografia líquida de alta eficiência (HPLC) e eletroforese capilar (CE), previamente validadas. Na melhor formulação foi obtida encapsulação de 51,4 ± 5,5 % para o diclofenaco e 66,9 ± 8,4 para a dexametasona.The great challenges of contemporary medicine emphasize the need for intensive research to develop new treatments for many chronic diseases, such as the rheumatic, to be effective, safe and of good quality. One of the new tools for the development of new drugs is the nanotechnology, which in recent years has increased its application in the pharmaceutical area contemplating a growing optimism about its potential use to get better opportunities for diagnosis and more effective therapies. In the present work were encapsulated two anti-inflammatories in nanoparticulate systems, nanospheres poly-lactic co-glycolic acid (PLGA), the technique used allows the encapsulation of hydrophilic and hydrophobic compounds in the same polymer nanoparticle, diclofenac sodium (DS) and dexamethasone (DX), respectively, obtaining nanoparticles with potential for the treatment of chronic inflammatory diseases. For the development of nanospheres the technique used was emulsion / solvent evaporation. The nanospheres were characterized by zeta potential infrared, particle size, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and pH. The encapsulation of the drug (diclofenac sodium and dexamethasone) in the nanospheres was performed by previously validated analytical techniques high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). In the best formulation was achieved encapsulation 51.4 ± 5.5% for diclofenac and 66.9 ± 8.4 for dexamethasone
7
Sun, Yanqi. "Studies of PLGA Nanoparticles for Pharmaceutical Applications". Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9232.
Texto completo da fonteResumo:
PLGA have already been successfully applied for controlled drug delivery systems by the pharmaceutical industry due to its biocompatibility, biodegradability and ease of processing. It has recently further been developed and formulated into a form of nanoparticle.
The single emulsion evaporation method was used to prepare nanoparticles in this study. By varying different parameters such as the concentration of regents, the type of surfactant and emulsion method, different particle sizes and size distribution of PLGA nanoparticles could be obtained.
The stability of PLGA nanoparticles was further investigated by assessing their thermal property over a certain period of time using DSC. The decrease of Tg confirmed the hydration and degradation of PLGA polymers and nanoparticles. The changes of surface morphology showed that the nanoparticles were in spherical shape and maintained smooth surface before the storage, whereas they started to lose their original shapes as well as agglomerate to each other after 2-week storage. These results suggested that there was an erosion and degradation of PLGA nanoparticles during storage.
Ibuprofen-loaded PLGA nanoparticles have been successfully prepared by o/w single emulsion evaporation method. During the stability study, a faster degradation rate compared to non-loaded PLGA nanoparticles was exhibited, showing that Ibuprofen increased the degradation rate of PLGA nanoparticles. According to the results of drug releasing study, PLGA nanoparticles exhibiting a slower drug release rate than pure drug which proved that drug-nanoparticule system could effectively increase the stability of drugs. PLGA polymer is a potential material for drug delivery system.
8
Schardosim, Mariane Giacomini. "Confecção de estruturas tubulares permeáveis de PLGA". Pontifícia Universidade Católica do Rio Grande do Sul, 2012. http://hdl.handle.net/10923/3335.
Texto completo da fonteResumo:
Made available in DSpace on 2013-08-07T18:54:45Z (GMT). No. of bitstreams: 1
000443125-Texto+Completo-0.pdf: 1527521 bytes, checksum: 2c9a9ef7ac02480e7ed3b2734a8acc04 (MD5)
Previous issue date: nullPeripheral nerve injury accident is a common type of lesion that can cause loss of mobility and decrease the quality of life. Despite advances in the biomedical area, there are few cases where there is complete functional recovery of a damaged nerve. The application of biodegradable polymers such as poly(lactide-co-glycolide) (PLGA), shows a viable alternative of treatment in peripheral nerves injuries for presenting mechanical strength, biocompatibility and controlled degradation, being also an excellent material for drug delivery. A PLGA scaffold should be porous with pore sizes on the order of micro-and nanometer, which offers the possibility to insert growth factors, promoting a constant release of these biological structures. The aim of this research is to produce porous scaffolds of PLGA. This was achieved by dissolving the polymer in chloroform, adding a porogenic compound. A titanium rod with 2mm in diameter was deeped in the suspension obtained and dried in a hood, obtaining a layer of PLGA / porogen agent on the surface of the rod. In sequence, the rod was immersed in a solution of PLGA with chloroform. After dried for 2 hours in a hood, the titanium rods were submerged in deionized water for 48 hours, during which the water was changed every 8 hours in order to remove the porogenic agent. After this process, the tubular structures formed were easily removed from the rods. Finally, the prepared tubes were divided into groups and treated with different concentrations of sodium hydroxide, to create pores in the order of nanometers, and subsequently vacuum dried for 48 hours. The structures obtained were characterized by XRD, FTIR, SEM and the in vitro degradation was monitored by GPC.
Danos a nervos periféricos são formas comuns de lesões que podem causar perda de mobilidade e diminuir a qualidade de vida. Apesar dos avanços no campo biomédico, existem poucos casos em que há recuperação funcional completa de um nervo danificado. A aplicação de polímeros biodegradáveis tais como PLGA, apresenta uma alternativa viável no tratamento de lesões de nervos periféricos por possuir resistência mecânica, biocompatibilidade e degradação controlada. Uma matriz de PLGA deve apresentar poros na ordem de micrômetros e nanômetros, oferecendo a possibilidade de inclusão de fatores de crescimento e possivelmente promovendo uma libertação constante destas estruturas biológicas. O objetivo desta pesquisa é produzir matrizes porosas de PLGA. Isto foi realizado através da dissolução do polímero em clorofórmio, seguida da adição de um composto porogênico. Uma haste de titânio com 2mm de diâmetro foi imersa na suspensão obtida e quando retirada, foi seca em capela, obtendo uma camada de PLGA/agente porogênico na superfície da haste. Na sequência, a haste foi imersa em uma solução de PLGA com clorofórmio. Após seca durante 2h em capela, as hastes de titânio foram submersas em água deionizada durante 48h, durante as quais, a água foi trocada a cada 8h, para remoção do agente porogênico. Após este processo, as estruturas tubulares formadas são facilmente removidas das hastes. Finalmente, os tubos confeccionados foram divididos em grupos, e tratados com diferentes concentrações de hidróxido de sódio, para criação de poros na ordem de nanômetros, sendo, subsequentemente, secos em forno a vácuo durante 48h. As estruturas obtidas foram caracterizadas por XRD, FTIR, MEV e a degradação in vitro foi acompanhada por GPC.
9
Maria, Adriana Del Monaco De. "Estudo do revestimento de modelos de stents coronários biorreabsorvíveis de PLLA com PLDLA/PLGA e ácido hialurônico". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/98/98131/tde-04102017-140345/.
Texto completo da fonteResumo:
A doença arterial coronariana vem sendo a maior causa de mortalidade no mundo, a angioplastia com implante de stent é uma estratégia importante nestes casos. Estudos apontam a biodegradabilidade, imobilização de antiproliferativos e moléculas bioativas nos stents, como características das futuras gerações destes dispositivos. Dentre estas, o ácido hialurônico contribui para a diminuição da agregação e proliferação de células entre as camadas da artéria e o dispositivo implantado. Foram desenvolvidos modelos de stents coronários biorreabsorvíveis de poli(-L-ácido láctico) (PLLA) com enxertia de ácido hialurônico (HA) em poli(-ácido lático co-ácido glicólico) (PLGA) e poli(L-D-ácido lático) (PLDLA). Os modelos foram caracterizados quanto suas propriedades térmicas, mecânicas e de superfície. O PLDLA e PLGA com enxertia de HA modificado com dihidrazida adípica (ADH) apresentaram características de superfície mais hidrofílicas, ideais para material de revestimento dos dispositivos. Desta forma, este trabalho possibilitou o desenvolvimento dos modelos físicos biorreabsorvíveis, com dimensões semelhantes aos stents coronários, feitos de PLLA, revestidos com PLGA e PLDLA com enxertia de HA e HAADH, e estáveis aos processos de esterilização por radiação ultravioleta e plasma de peróxido de hidrogênio.Coronary artery disease has been world´s leading cause of death and angioplasty stent implantation is an important strategy in these cases. Studies indicate that the biodegradability, immobilization of antiproliferatives and bioactive molecules in stents are characteristics of future generations of these medical devices. Amongst them, hyaluronic acid (HA) contributes to the decrease of the aggregation and proliferation of cells between artery layers and implanted device. For this purpose, poly (L-lactic acid) (PLLA) bioresorbable coronary stents with HA grafting in poly (lactic acid-co-glycolic acid) (PLGA) and poly (LD- (PLDLA) were developed. The models were characterized as their thermal, mechanical and surface properties. PLDLA and PLGA with adipic dihydrazide (ADH) modified HA grafting presented more hydrophilic surface characteristics, ideal as coating material of this devices. This project allowed the development of bioresorbable physical models with similar dimensions to coronary stents, made of PLLA, coated with PLGA and PLDLA with hyaluronic acid grafting, stable to ultraviolet radiation and plasma sterilization with hydrogen peroxide processes.
10
El, Abbouni Sarah. "Microencapsulation of LL-37 Antimicrobial Peptide in PLGA". Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/235.
Texto completo da fonteResumo:
Antimicrobial peptides are key actors in organisms€™ immune systems. They play an important role in phagocytosis, breaking bacteria membranes. They destroy the microbes, keeping them from repairing themselves, and therefore do not promote antimicrobial resistance. LL37 is a peptide produced by the human body. It is a short amino acid chain that is particularly active on the skin and mucous membranes. It has antimicrobial and fungal activity as well as wound healing properties, which makes it a very interesting active substance in wound treatment. However, its fragile and sensitive structure is a challenge to its use. Nowadays, encapsulation in a biocompatible polymer system is a promising technique in drug delivery, and presents a solution to LL37 administration and delivery. LL37 is a hydrophilic active substance, it will be trapped in PLGA (poly (lactic-co-glycolic acid)) by double emulsion and the microspheres will be shaped and stabilized by solvent evaporation. The capsules will be characterized by Dynamic Light Scattering (DLS) and Scanning Electron Microscopy. Their main features, drug loading, encapsulation efficiency and release profile, are determined using the Bradford assay. Since the peptide is expensive and delicate, it is important to optimize its encapsulation. For that reason, we will adapt the process to have the best drug loading as possible using water in oil in oil emulsions. For an external use, the capsules would be used over a few days, so having a fast release is very relevant. The larger the specific surface area, the faster the diffusion. For that reason, we will also study the impact of porosity on the release profile. As a result, different types of capsules will be synthesized, with higher porosity and by two processes: aqueous double emulsion and oil double emulsion. Their characteristic features and impact on bacterial pathogens will be determined and compared in order to determine their optimal synthesis process and formulation in given conditions of use.
Livros sobre o assunto "PLGA"
1
Joseph, Jamie William. Oral delivery of glucagon-like peptide-1 using PLGA-COOH microspheres. Ottawa: National Library of Canada, 1999.
Encontre o texto completo da fonte
2
Beernaert, Marie-Aude. Repentis et collaborateurs de justice dans le système pénal: Analyse comparée et critique. Bruxelles: Bruylant, 2002.
Encontre o texto completo da fonte
3
Weigend, Thomas. Absprachen in ausländischen Strafverfahren: Eine rechtsvergleichende Untersuchung zu konsensualen Elementen im Strafprozess. Freiburg i. Br: Max-Planck-Institut für Ausländisches und Internationales Strafrecht, 1990.
Encontre o texto completo da fonte
4
Phiradāusa, Śāhyāda. Plega. Kalakātā: Baṅga Basundhāra, 1996.
Encontre o texto completo da fonte
5
Flynn, Asher, e Arie Freiberg. Plea Negotiations. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-92630-8.
Texto completo da fonte
6
Roden, Katie. Plag ue. Brookfield, Conn: Copper Beech Books, 1996.
Encontre o texto completo da fonte
9
Waugh, Hillary. Prisoner's plea. Bath, England: Chivers Press, 1990.
Encontre o texto completo da fonte
10
Herman, G. Nicholas. Plea bargaining. 2a ed. [Charlottesville, Va.]: LexisNexis, 2004.
Encontre o texto completo da fonteCapítulos de livros sobre o assunto "PLGA"
1
Marques, Shirleen Miriam, e Lalit Kumar. "PKPD of PLGA-PEG-PLGA Copolymeric Micelles". In Pharmacokinetics and Pharmacodynamics of Nanoparticulate Drug Delivery Systems, 273–92. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-83395-4_15.
Texto completo da fonte
2
Rosales-Mendoza, Sergio, e Omar González-Ortega. "PLGA-Based Mucosal Nanovaccines". In Nanovaccines, 61–103. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-31668-6_4.
Texto completo da fonte
3
Rosa, Giuseppe De, e Giuseppina Salzano. "PLGA Microspheres Encapsulating siRNA". In RNA Interference, 43–51. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1538-5_4.
Texto completo da fonte
4
Kawashima, Yoshiaki. "Application of PLGA NSs to Cosmetics". In Spherical Crystallization as a New Platform for Particle Design Engineering, 99–106. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-6786-1_7.
Texto completo da fonte
5
Joy, Jomon, e Sabu Thomas. "PLGA-Based Nanoparticles for Cancer Therapy". In Nanoparticles in Polymer Systems for Biomedical Applications, 23–56. Oakville, Canada ; Waretown, NJ : Apple Academic Press, [2019]: Apple Academic Press, 2018. http://dx.doi.org/10.1201/9781351047883-2.
Texto completo da fonte
6
Zhang, Siyao, David James Young e Xian Jun Loh. "Chapter 2. Thermogelling PLGA-based Copolymers". In Biomaterials Science Series, 23–39. Cambridge: Royal Society of Chemistry, 2018. http://dx.doi.org/10.1039/9781788012676-00023.
Texto completo da fonte
7
Chaurasiya, Akash, Parameswar Patra, Pranathi Thathireddy e Amruta Gorajiya. "PLGA-Based Micro- and Nano-particles". In Micro- and Nanotechnologies-Based Product Development, 83–94. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003043164-6.
Texto completo da fonte
8
Gultekin, Yakup, Tamer Tekin, Meryem Kocas, Yılmaz Capan e Adem Sahin. "PLGA-Based Nanomaterials for Cancer Therapy". In Nanotechnology for Biomedical Applications, 263–84. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7483-9_13.
Texto completo da fonte
9
Atanasov, Gjorgji, Iliyan N. Kolev, Ognyan Petrov e Margarita D. Apostolova. "Synthesis of PLGA-PEG-PLGA Polymer Nano-Micelles – Carriers of Combretastatin-Like Antitumor Agent 16Z". In NATO Science for Peace and Security Series B: Physics and Biophysics, 449–58. Dordrecht: Springer Netherlands, 2020. http://dx.doi.org/10.1007/978-94-024-2018-0_36.
Texto completo da fonte
10
Ren, Ling, Jin Wang, Jia Ju Tang, Ch J. Pang, M. Maitz e Nan Huang. "Biological Evaluation of Sirolimus-Loaded PLGA Films". In Advanced Biomaterials VII, 837–40. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-436-7.837.
Texto completo da fonteTrabalhos de conferências sobre o assunto "PLGA"
1
Lee, So-i., Joung Soon Park, Min Kyu Park e Ja Kyung Koo. "Physical Property of Absorbable Suture PLLA I PLLA II PLGA PDO". In Green and Smart Technology 2015. Science & Engineering Research Support soCiety, 2015. http://dx.doi.org/10.14257/astl.2015.120.02.
Texto completo da fonte
2
Weigum, Shannon E., Melissa Sutton, Eugenia Barnes, Sarah Miller e Tania Betancourt. "Targeting hepatocellular carcinoma with aptamer-functionalized PLGA/PLA-PEG nanoparticles". In SPIE NanoScience + Engineering, editado por Hooman Mohseni, Massoud H. Agahi e Manijeh Razeghi. SPIE, 2014. http://dx.doi.org/10.1117/12.2062283.
Texto completo da fonte
3
Benammar, Sarra, Fatima Mraiche, Jensa Mariam Joseph e Katerina Gorachinova. "Glucose and Transferrin Liganded PLGA Nanoparticles Internalization in Non-Small Lung Cancer Cells". In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0227.
Texto completo da fonteResumo:
Introduction: Recently, after a decade of confusing results, several studies pointed out that overexpression of GLUT1 (glucose transporter 1) is a biomarker of worse prognosis in NSCLC. Nonetheless, the presence of transferrin (Tf receptor), which is overexpressed in most cancer tissues and most lung cancers as well, in NSCLC is also an indicator of very poor prognosis. Therefore, these ligands can be used for active targeting of lung cancer cells and improved efficacy of internalization of cancer therapy using nanomedicines. Objectives: Having the background, the main goal of the project was the assessment of the influence of the glucose and transferrin ligands on the efficacy of internalization of the designed (i) glucose decorated PLGA (poly lactic-coglycolic acid) nanoparticles (Glu-PLGA NPs) and (ii) transferrin decorated PLGA nanoparticles (Tf-PLGA NPs) in comparison to (iii) non-liganded PLGA NPs using a A549 lung cancer cells. Methods: Glu-PLGA NPs, Tf-PLGA NPs and PLGA NP - fluorescently labelled), were designed using a sonication assisted nanoprecipitation method. Further, physicochemical properties characterization (particle size analysis, zeta potential, FTIR analysis, DSC analysis), cytotoxicity evaluation using MTT test, and cell internalization studies of DTAF labelled NPs using fluorimetry in A549 NSCLC cell line were performed. Results: The results pointed to a significantly improved internalization rate of the liganded compared to PLGA NPs. Glu-PLGA NPs showed higher internalization rate compared to Tf-PLGA and PLGA NPs, in the serum-supplemented and serumfree medium even at normal levels of glucose in the cell growth medium. Conclusion: The developed nanocarriers offer unique advantages of enhanced targetability, improved cell internalization and decreased toxicity, which makes them promising solution for current therapeutic limitations.
4
Ramalho, M. J., J. A. Loureiro, B. Gomes, M. F. Frasco, M. A. N. Coelho e M. C. Pereira. "PLGA nanoparticles for calcitriol delivery". In 2015 IEEE 4th Portuguese Meeting on Bioengineering (ENBENG). IEEE, 2015. http://dx.doi.org/10.1109/enbeng.2015.7088884.
Texto completo da fonte
5
Wang, Gou-Jen, e Cheng-Chih Hsueh. "Fabrication of PLGA Microstructures Made Up of Circular Microchannels Using Soft Lithography". In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-34321.
Texto completo da fonteResumo:
A simple micromolding method to fabricate PLGA microstructures made up of microchannels with circular cross section is presented. The thermal reflow technique is adopted to fabricate the semi-cylindrical photoresist master. The PLGA solution is prepared by dissolving PLGA polymer in acetone and then casting the solution onto the semi-cylindrical photoresist master to produce PLGA microstructures. Two PLGA membranes are bonded together to form the circular microchannels consisted microstructures. A microvessel scaffold for tissue engineering by implementing the proposed method is fabricated. Roundness of the microchannels is verified.
6
Yalcin, Huseyin, Hissa Al-Thani e Samar Shurbaji. "Development and In Vivo Testing of Smart Nanoparticles for Enhanced Anti-Cancer Activity and Reduced Cardiotoxicity Associated with Tyrosine Kinase Inhibitors". In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0088.
Texto completo da fonteResumo:
Tyrosine kinase inhibitors (TKIs) are new generation of anti-cancer drugs with very high efficiency against cancer cells. However, TKIs are associated with severe cardiotoxicity limiting their clinical benefits. One TKI that has been developed recently but not explored much is Ponatinib. The use of nanoparticles as a better therapeutic agent to deliver anti-cancer drugs and reduce their cardiotoxicity has been recently considered. In this study, PLGA-PEG-PLGA nanoparticles were synthesized to deliver Ponatinib while reducing its cardiotoxicity for treatment of chronic myeloid leukemia. Shape, size, surface charge and drug uptake ability of these nanoparticles were assessed using transmission electron microscopy (TEM), ZetaSIZER NANO and high-performance liquid chromatography (HPLC). Cardiotoxicity of Ponatinib, unloaded and loaded PLGA-PEG-PLGA nanoparticles were studied on zebrafish model through measuring the survival rate and cardiac function parameters, to optimize efficient drug concentrations in an in vivo setting. These particles were tested on zebrafish cancer xenograft model in which, K562 cell line, was transplanted into zebrafish embryos. We showed that, at an optimal concentration (0.0025mg/ml), Ponatinib loaded PLGA-PEG-PLGA particles are non-toxic/non-cardio-toxic and are very efficient against cancer growth and metastasis. Zebrafish is a good animal model for investigating the cardiotoxicity associated with the anti-cancer drugs such as TKIs, to determine the optimum concentration of smart nanoparticles with the least side effects and to generate xenograft model of several cancer types. Also, PLGA-PEG-PLGA NPs could be good candidate for CML treatment, but their cellular internalization should be enhanced. This could be achieved by coating and labeling the surface of PLGA-PEG-PLGA NPs with specific ligands that are unique to CML cells.
7
Krishnakumar, D., e K. S. Jaganathan. "Development of nasal HPV vaccine formulations". In 16th Annual International Conference RGCON. Thieme Medical and Scientific Publishers Private Ltd., 2016. http://dx.doi.org/10.1055/s-0039-1685403.
Texto completo da fonteResumo:
Cervical cancer is the second most cancer in women worldwide with over 500000 new cases and 275000 deaths being registered every year. With nearly 73000 women dying every year, India now tops the world in cervical cancer deaths. India represents 26.4% of all women dying of cervical cancer globally. Cervical cancer estimated to be responsible for about 5% of human cancers worldwide. Currently available vaccines may not provide complete protection against all HPV types as the protection is primarily type specific. Furthermore, the available vaccines are delivered via intramuscular route and require three doses and require cold chain supply which increases the cost of vaccine. Therefore a single dose vaccine delivered via non-invasive route (nasal) that protects against multiple HPV types would be a cost effective and better alternative to the currently available HPV vaccines. The main objective of this study was to prepare HPV antigen loaded poly (lactic-co-glycolic acid) (PLGA) and Tri Methyl Chitosan (TMC) coated PLGA microparticles and compare their efficacy as nasal vaccine. The developed formulations were characterized for size, zeta potential, entrapment efficiency, mucin adsorption ability, in vitro and in vivo studies. PLGA microparticles demonstrated negative zeta potential whereas PLGA-TMC microparticles showed higher positive zeta potential. The protein loading efficiency was found as above 80%. Results indicated that PLGA-TMC microparticles demonstrated substantially higher mucin adsorption when compared to PLGA microparticles. HPV antigen encapsulated in PLGA-TMC particles elicited a significantly higher secretory (IgA) immune response compared to that encapsulated in PLGA particles. Present study demonstrates that PLGA-TMC microparticles with specific size range can be a better carrier adjuvant for nasal subunit vaccines. Surface modified PLGA microparticles proved great potential as a nasal delivery system for HPV infections where systemic and mucosal responses are necessary particularly in conditions after viral pathogens invade the host through the mucosal surface.
8
Hosayni, L., F. Ganji e E. Khodaverdi. "Effects of reaction condition and feed composition on thermo-gelling behavior of PLGA-PEG-PLGA". In 2012 19th Iranian Conference of Biomedical Engineering (ICBME). IEEE, 2012. http://dx.doi.org/10.1109/icbme.2012.6519669.
Texto completo da fonte
9
Jayasuriya, A. Champa, Elisabeth Michels e Nabil A. Ebraheim. "Demineralized Bone Matrix Incorporated PLGA Matrices". In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14796.
Texto completo da fonteResumo:
Poly(lactic-co-glycolic acid)-PLGA (85:15) films incorporated with demineralized bone matrix (DBM) powder with the weight ratio of polymer: DBM (75:25) were investigated for release of agents including osteoinductive (OI) factors during the 80 day period exposing to Phosphate Buffered Saline (PBS) at 37 °C. The release amount of agents including OI factors from DBM/PLGA matrices were more than 2-fold higher at 70 days than at 10 days, respectively. This result demonstrated that controlled release of OI factors can be achieved for extended time period at target site using PLGA as a carrier for DBM powder. Murine Bone Marrow Stromal Cell (BMSC) attachment was studied with different time points at 30 min, 1 h, 2 h, 4 h, 6 h and 24 h for DBM/PLGA and PLGA control matrices. Significantly higher number of BMSCs was attached to the DBM/PLGA matrices at each time points compared with controls. This result suggests that BMSCs favor to attach the surfaces having OI properties. If DBM is incorporated into biodegradable 3-D polymer scaffolds and culture with BMSCs, those scaffolds could be potentially used for bone tissue engineering applications.
10
Rahman, Shekh, e Narayan Bhattarai. "Magnesium Oxide Based PLGA/Chitosan Microparticles for Controlled Release Study". In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52143.
Texto completo da fonteResumo:
The performance of a therapeutic drug can be optimized by controlling the rate and extent of its release in the body. Polymeric microparticles are ideal vehicles for many controlled release drug delivery applications. Poly(lactic-co-glycolic acid) (PLGA) is a biodegradable, biocompatible and FDA approved synthetic polymer. When PLGA based controlled release drug delivery devices are fabricated, the surface of PLGA is typically modified by other hydrophilic polymers. But some hydrophilic polymers, such as poly(ethylene glycol) (PEG) can negatively influence the therapeutic outcomes. The goal of the present study was to fabricate and investigate the PLGA/chitosan microparticles for controlled release of therapeutic drugs. Chitosan is a naturally occurring biodegradable polysaccharide. We hypothesized that chitosan could be used as a surface coating of PLGA to improve controlled release of therapeutic drugs. The double emulsion solvent evaporation technique was modified and utilized to fabricate the PLGA/chitosan microparticles. The microparticles were tested with respect to several physicochemical properties, such as morphology, size distribution, chemical structure, quantification of chitosan content and in vitro release study of model drug. Magnesium is an essential electrolyte in the human body. Magnesium oxide (MgO) is used for treatment of magnesium deficiency. MgO was encapsulated in the PLGA/chitosan microparticles as a model drug.
Relatórios de organizações sobre o assunto "PLGA"
1
Hassan, Mozan, Abbas Khaleel, Sherif Karam, Ali Al-Marzouqi, Ihtesham Ur Rehman e Sahar Mohsin. Bacterial inhibition and osteogenic potentials of Sr/Zn co-doped nano-hydroxyapatite-PLGA composite scaffold for bone tissue engineering applications. Peeref, junho de 2023. http://dx.doi.org/10.54985/peeref.2306p7862520.
Texto completo da fonte
2
Oimoen, Daniel C. PLGR Accuracy Evaluation. Fort Belvoir, VA: Defense Technical Information Center, junho de 1994. http://dx.doi.org/10.21236/ada281291.
Texto completo da fonte
3
Miller, Marc. PLA Missions Beyond Taiwan. Fort Belvoir, VA: Defense Technical Information Center, outubro de 2008. http://dx.doi.org/10.21236/ada487962.
Texto completo da fonte
4
Burt, Andrew, e Daniel Geer, Jr. A Plea: The Case for Digital Environmentalism. Center for Security and Emerging Technology, novembro de 2022. http://dx.doi.org/10.51593/2022ca005.
Texto completo da fonteResumo:
Digital technology, the defining innovation of the last half century, has deep and unaddressed insecurities at its core. This paper, authored by two prominent technologists and strategic thinkers, argues that a new form of “digital environmentalism”—marked by a re-evaluation of our relationship to technology, growth, and innovation—is the only way to fix such insecurities, and to bring meaningful change to the digital world.
5
Dreyer, June T. The Pla and the Kosovo Conflict. Fort Belvoir, VA: Defense Technical Information Center, maio de 2000. http://dx.doi.org/10.21236/ada382839.
Texto completo da fonte
6
Papachristou, Christos A. Structured Microcontroller Design Using PLA Firmware. Fort Belvoir, VA: Defense Technical Information Center, dezembro de 1985. http://dx.doi.org/10.21236/ada164255.
Texto completo da fonte
7
Barefoot, Susan F., Bonita A. Glatz, Nathan Gollop e Thomas A. Hughes. Bacteriocin Markers for Propionibacteria Gene Transfer Systems. United States Department of Agriculture, junho de 2000. http://dx.doi.org/10.32747/2000.7573993.bard.
Texto completo da fonteResumo:
The antibotulinal baceriocins, propionicin PLG-1 and jenseniin G., were the first to be identified, purified and characterized for the dairy propionibaceria and are produced by Propionibacterium thoenii P127 and P. thoenii/jensenii P126, respectively. Objectives of this project were to (a) produce polyclonal antibodies for detection, comparison and monitoring of propionicin PLG-1; (b) identify, clone and characterize the propionicin PLG-1 (plg-1) and jenseniin G (jnG) genes; and (3) develop gene transfer systems for dairy propionibacteria using them as models. Polyclonal antibodies for detection, comparison and monitoring of propionicin PLG-1 were produced in rabbits. Anti-PLG-1 antiserum had high titers (256,000 to 512,000), neutralized PLG-1 activity, and detected purified PLG-1 at 0.10 mg/ml (indirect ELISA) and 0.033 mg/ml (competitive indirect ELISA). Thirty-nine of 158 strains (most P. thoenii or P. jensenii) yielded cross-reacting material; four strains of P. thoenii, including two previously unidentified bacteriocin producers, showed biological activity. Eight propionicin-negative P127 mutants produced neither ELISA response nor biological activity. Western blot analyses of supernates detected a PLG-1 band at 9.1 kDa and two additional protein bands with apparent molecular weights of 16.2 and 27.5 kDa. PLG-1 polyclonal antibodies were used for detection of jenseniin G. PLG-1 antibodies neutralized jenseniin G activity and detected a jenseniin G-sized, 3.5 kDa peptide. Preliminary immunoprecipitation of crude preparations with PLG-1 antibodies yielded three proteins including an active 3-4 kDa band. Propionicin PLG-1 antibodies were used to screen a P. jensenii/thoenii P126 genomic expression library. Complete sequencing of a cloned insert identified by PLG-1 antibodies revealed a putative response regulator, transport protein, transmembrane protein and an open reading frame (ORF) potentially encoding jenseniin G. PCR cloning of the putative plg-1 gene yielded a 1,100 bp fragment with a 355 bp ORF encoding 118 amino acids; the deduced N-terminus was similar to the known PLG-1 N-terminus. The 118 amino acid sequence deduced from the putative plg-1 gene was larger than PLG-1 possibly due to post-translational processing. The product of the putative plg-1 gene had a calculated molecular weight of 12.8 kDa, a pI of 11.7, 14 negatively charged residues (Asp+Glu) and 24 positively charged residues (Arg+Lys). The putative plg-1 gene was expressed as an inducible fusion protein with a six-histidine residue tag. Metal affinity chromatography of the fused protein yielded a homogeneous product. The fused purified protein sequence matched the deduced putative plg-1 gene sequence. The data preliminarily suggest that both the plg-1 and jnG genes have been identified and cloned. Demonstrating that antibodies can be produced for propionicin PLG-1 and that those antibodies can be used to detect, monitor and compare activity throughout growth and purification was an important step towards monitoring PLG-1 concentrations in food systems. The unexpected but fortunate cross-reactivity of PLG-1 antibodies with jenseniin G led to selective recovery of jenseniin G by immunoprecipitation. Further refinement of this separation technique could lead to powerful affinity methods for rapid, specific separation of the two bacteriocins and thus facilitate their availability for industrial or pharmaceutical uses. Preliminary identification of genes encoding the two dairy propionibacteria bacteriocins must be confirmed; further analysis will provide means for understanding how they work, for increasing their production and for manipulating the peptides to increase their target species. Further development of these systems would contribute to basic knowledge about dairy propionibacteria and has potential for improving other industrially significant characteristics.
8
Vega, Richard Manuel, Edward J. Parm, Patrick J. Griffin e David W. Vehar. Neutron Reference Benchmark Field Specifications: ACRR Polyethylene-Lead-Graphite (PLG) Bucket Environment (ACRR-PLG-CC-32-CL). Office of Scientific and Technical Information (OSTI), julho de 2015. http://dx.doi.org/10.2172/1191880.
Texto completo da fonte
9
Rudell, Richard L. Multiple-Valued Logic Minimization for PLA Synthesis. Fort Belvoir, VA: Defense Technical Information Center, junho de 1986. http://dx.doi.org/10.21236/ada606736.
Texto completo da fonte
10
Duffin, Matthew L. Plea-Bargaining in International Criminal Tribunals: A Legitimate and Necessary Tool. Fort Belvoir, VA: Defense Technical Information Center, novembro de 1999. http://dx.doi.org/10.21236/ada370523.
Texto completo da fonte