Journal articles: 'Interfacial tissues'

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Hench, Larry L., and Julia M. Polak. "A Genetic Basis for Design of Biomaterials for In Situ Tissue Regeneration." Key Engineering Materials 377 (March 2008): 151–66. http://dx.doi.org/10.4028/www.scientific.net/kem.377.151.

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Historically the function of biomaterials has been to replace diseased, damaged and aged tissues. First generation biomaterials, including bio ceramics, were selected to be as inert as possible in order to minimize the thickness of interfacial scar tissue. Bioactive glasses provided an alternative from the 1970’s onward; second generation bioactive bonding of implants with tissues and no interfacial scar tissue. This chapter reviews the discovery that controlled release of biologically active Ca and Si ions from bioactive glasses leads to the up-regulation and activation of seven families of genes in osteoprogenitor cells that give rise to rapid bone regeneration. This finding offers the possibility of creating a new generation of gene activating bioceramics designed specially for tissue engineering and in situ regeneration of tissues.

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Michel, Raphaël, Léna Poirier, Quentin van Poelvoorde, Josette Legagneux, Mathieu Manassero, and Laurent Corté. "Interfacial fluid transport is a key to hydrogel bioadhesion." Proceedings of the National Academy of Sciences 116, no. 3 (January 2, 2019): 738–43. http://dx.doi.org/10.1073/pnas.1813208116.

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Attaching hydrogels to soft internal tissues is a key to the development of a number of biomedical devices. Nevertheless, the wet nature of hydrogels and tissues renders this adhesion most difficult to achieve and control. Here, we show that the transport of fluids across hydrogel−tissue interfaces plays a central role in adhesion. Using ex vivo peeling experiments on porcine liver, we characterized the adhesion between model hydrogel membranes and the liver capsule and parenchyma. By varying the contact time, the tissue hydration, and the swelling ratio of the hydrogel membrane, a transition between two peeling regimes is found: a lubricated regime where a liquid layer wets the interface, yielding low adhesion energies (0.1 J/m2 to 1 J/m2), and an adhesive regime with a solid binding between hydrogel and tissues and higher adhesion energies (1 J/m2 to 10 J/m2). We show that this transition corresponds to a draining of the interface inducing a local dehydration of the tissues, which become intrinsically adhesive. A simple model taking into account the microanatomy of tissues captures the transition for both the liver capsule and parenchyma. In vivo experiments demonstrate that this effect still holds on actively hydrated tissues like the liver capsule and show that adhesion can be strongly enhanced when using superabsorbent hydrogel meshes. These results shed light on the design of predictive bioadhesion tests as well as on the development of improved bioadhesive strategies exploiting interfacial fluid transport.

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Cerchiari, Alec E., James C. Garbe, Noel Y. Jee, Michael E. Todhunter, Kyle E. Broaders, Donna M. Peehl, Tejal A. Desai, Mark A. LaBarge, Matthew Thomson, and Zev J. Gartner. "A strategy for tissue self-organization that is robust to cellular heterogeneity and plasticity." Proceedings of the National Academy of Sciences 112, no. 7 (January 29, 2015): 2287–92. http://dx.doi.org/10.1073/pnas.1410776112.

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Developing tissues contain motile populations of cells that can self-organize into spatially ordered tissues based on differences in their interfacial surface energies. However, it is unclear how self-organization by this mechanism remains robust when interfacial energies become heterogeneous in either time or space. The ducts and acini of the human mammary gland are prototypical heterogeneous and dynamic tissues comprising two concentrically arranged cell types. To investigate the consequences of cellular heterogeneity and plasticity on cell positioning in the mammary gland, we reconstituted its self-organization from aggregates of primary cells in vitro. We find that self-organization is dominated by the interfacial energy of the tissue–ECM boundary, rather than by differential homo- and heterotypic energies of cell–cell interaction. Surprisingly, interactions with the tissue–ECM boundary are binary, in that only one cell type interacts appreciably with the boundary. Using mathematical modeling and cell-type-specific knockdown of key regulators of cell–cell cohesion, we show that this strategy of self-organization is robust to severe perturbations affecting cell–cell contact formation. We also find that this mechanism of self-organization is conserved in the human prostate. Therefore, a binary interfacial interaction with the tissue boundary provides a flexible and generalizable strategy for forming and maintaining the structure of two-component tissues that exhibit abundant heterogeneity and plasticity. Our model also predicts that mutations affecting binary cell–ECM interactions are catastrophic and could contribute to loss of tissue architecture in diseases such as breast cancer.

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Grandfield, Kathryn, Anders Palmquist, and Håkan Engqvist. "High-resolution three-dimensional probes of biomaterials and their interfaces." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1963 (March 28, 2012): 1337–51. http://dx.doi.org/10.1098/rsta.2011.0253.

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Interfacial relationships between biomaterials and tissues strongly influence the success of implant materials and their long-term functionality. Owing to the inhomogeneity of biological tissues at an interface, in particular bone tissue, two-dimensional images often lack detail on the interfacial morphological complexity. Furthermore, the increasing use of nanotechnology in the design and production of biomaterials demands characterization techniques on a similar length scale. Electron tomography (ET) can meet these challenges by enabling high-resolution three-dimensional imaging of biomaterial interfaces. In this article, we review the fundamentals of ET and highlight its recent applications in probing the three-dimensional structure of bioceramics and their interfaces, with particular focus on the hydroxyapatite–bone interface, titanium dioxide–bone interface and a mesoporous titania coating for controlled drug release.

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Sahu, Preeti, Daniel M. Sussman, Matthias Rübsam, Aaron F. Mertz, Valerie Horsley, Eric R. Dufresne, Carien M. Niessen, M. Cristina Marchetti, M. Lisa Manning, and J. M. Schwarz. "Small-scale demixing in confluent biological tissues." Soft Matter 16, no. 13 (2020): 3325–37. http://dx.doi.org/10.1039/c9sm01084j.

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While interfacial tension in confluent cellular mixtures leads to large-scale demixing, cell shape disparity leads to robust small-scale demixing that is observed in experiments and can be explained via neighbor exchange barriers at an interface.

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Mckee, Marc D., and Antonio Nanci. "Osteopontin: An Interfacial Extracellular Matrix Protein in Mineralized Tissues." Connective Tissue Research 35, no. 1-4 (January 1996): 197–205. http://dx.doi.org/10.3109/03008209609029192.

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7

Foty, Ramsey A., Gabor Forgacs, Cathie M. Pfleger, and Malcolm S. Steinberg. "Liquid properties of embryonic tissues: Measurement of interfacial tensions." Physical Review Letters 72, no. 14 (April 4, 1994): 2298–301. http://dx.doi.org/10.1103/physrevlett.72.2298.

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8

Otagiri, Risa, Hideki Kawai, Masanobu Takatsuka, Naoki Shinyashiki, Akira Ito, Ryosuke Ikeguchi, and Tomoki Aoyama. "Interfacial polarization of in vivo rat sciatic nerve with crush injury studied via broadband dielectric spectroscopy." PLOS ONE 16, no. 6 (June 2, 2021): e0252589. http://dx.doi.org/10.1371/journal.pone.0252589.

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Electrical stimulation is one of the candidates for elongation-driven regeneration of damaged peripheral nerves. Different organs and tissues have an inherent cell structure and size. This leads to variation in the tissue-specific electrical properties of the frequency of interfacial polarization. Although nervous tissues have a membrane potential, the electrical reaction inside these tissues following electrical stimulation from outside remains unexplored. Furthermore, the pathophysiological reaction of an injured nerve is unclear. Here, we investigated the electrical reaction of injured and non-injured rat sciatic nerves via broadband dielectric spectroscopy. Crush injured and non-injured sciatic nerves of six 12-week-old male Lewis rats were used, 6 days after infliction of the injury. Both sides of the nerves (with and without injury) were exposed, and impedance measurements were performed at room temperature (approximately 25°C) at frequencies ranging from 100 mHz to 5.5 MHz and electric potential ranging from 0.100 to 1.00 V. The measured interfacial polarization potentially originated from the polarization by ion transport around nerve membranes at frequencies between 3.2 kHz and 1.6 MHz. The polarization strength of the injured nerves was smaller than that of non-injured nerves. However, the difference in polarization between injured and non-injured nerves might be caused by inflammation and edema. The suitable frequency range of the interfacial polarization can be expected to be critical for electrical stimulation of injured peripheral nerves.

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9

Lok, P., Philip Boughton, T. Kishen, and Ashish D. Diwan. "Geometrical & Interfacial Modulation of a Biomimetic Spinal Implant." Journal of Biomimetics, Biomaterials and Tissue Engineering 4 (December 2009): 41–58. http://dx.doi.org/10.4028/www.scientific.net/jbbte.4.41.

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The nucleus of a spinal disc is seamlessly connective and protectively supportive of the joint within which it is enveloped. A range of nucleus prosthesis configurations have been proposed and applied with some success. Those that have demonstrated clinical efficacy have approximated physiological form and function using established biomaterials while preserving key anatomical structures. The minimally invasive biostable, biomimetic Columna Disc Device (CDD) partial spinal disc replacement has been developed to clinical trial stage. It mimics the geometry and response of the nucleus that it replaces. While the implant configuration and materials have been set, the geometry and interfacial properties of this prosthesis may be modulated to account for versatility in surgical deployment, implant stiffness, and subsequent long-term tissue remodelling response. FEA models were developed to study effects of implant jacket geometry and surface properties on implant deployment and biomechanics. Studded and dimpled textures provide a method for increasing surface area to diffuse jacket-filler interfacial stress and similar for the implant-tissue junction. Surface texture design elements observed in nature can protect against delamination and interlayer slippage. This is the case with adherent outer layers of human skin. A textured implant design is also proposed to guard against third body wear by housing debris remote of wear sites and by reducing sliding. The periodically varying strain fields provided by the textured jacket may also help mitigate for tears by diverting and arresting micro-fissures. Increasing friction at the implant-tissue interface to the point of tissue-attachment was shown to increase the stiffness of the implant in axial-loading. In contrast, increasing bulk surface area is expected to contribute to a decrease in implant stiffness. This is, however, dependent on the intimacy and properties of interfacing tissues.

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10

Chen, Xiaoyu, Hyunwoo Yuk, Jingjing Wu, Christoph S. Nabzdyk, and Xuanhe Zhao. "Instant tough bioadhesive with triggerable benign detachment." Proceedings of the National Academy of Sciences 117, no. 27 (June 23, 2020): 15497–503. http://dx.doi.org/10.1073/pnas.2006389117.

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Bioadhesives such as tissue adhesives, hemostatic agents, and tissue sealants have potential advantages over sutures and staples for wound closure, hemostasis, and integration of implantable devices onto wet tissues. However, existing bioadhesives display several limitations including slow adhesion formation, weak bonding, low biocompatibility, poor mechanical match with tissues, and/or lack of triggerable benign detachment. Here, we report a bioadhesive that can form instant tough adhesion on various wet dynamic tissues and can be benignly detached from the adhered tissues on demand with a biocompatible triggering solution. The adhesion of the bioadhesive relies on the removal of interfacial water from the tissue surface, followed by physical and covalent cross-linking with the tissue surface. The triggerable detachment of the bioadhesive results from the cleavage of bioadhesive’s cross-links with the tissue surface by the triggering solution. After it is adhered to wet tissues, the bioadhesive becomes a tough hydrogel with mechanical compliance and stretchability comparable with those of soft tissues. We validate in vivo biocompatibility of the bioadhesive and the triggering solution in a rat model and demonstrate potential applications of the bioadhesive with triggerable benign detachment in ex vivo porcine models.

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11

Olien, C. Robert, and David P. Livingston. "Understanding freeze stress in biological tissues: Thermodynamics of interfacial water." Thermochimica Acta 451, no. 1-2 (December 2006): 52–56. http://dx.doi.org/10.1016/j.tca.2006.08.014.

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12

Stupp, S. I., and R. Kusleika. "Surface charge on polymeric implants and calcified tissues: Interfacial implications." Journal of Biomedical Materials Research 19, no. 3 (March 1985): 321–34. http://dx.doi.org/10.1002/jbm.820190313.

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13

Gun’ko, V. M., V. V. Turov, A. P. Shpilko, R. Leboda, M. Jablonski, M. Gorzelak, and E. Jagiello-Wojtowicz. "Relationships between characteristics of interfacial water and human bone tissues." Colloids and Surfaces B: Biointerfaces 53, no. 1 (November 2006): 29–36. http://dx.doi.org/10.1016/j.colsurfb.2006.07.016.

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14

Kim, Min Guk, and Chan Ho Park. "Tooth-Supporting Hard Tissue Regeneration Using Biopolymeric Material Fabrication Strategies." Molecules 25, no. 20 (October 19, 2020): 4802. http://dx.doi.org/10.3390/molecules25204802.

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The mineralized tissues (alveolar bone and cementum) are the major components of periodontal tissues and play a critical role to anchor periodontal ligament (PDL) to tooth-root surfaces. The integrated multiple tissues could generate biological or physiological responses to transmitted biomechanical forces by mastication or occlusion. However, due to periodontitis or traumatic injuries, affect destruction or progressive damage of periodontal hard tissues including PDL could be affected and consequently lead to tooth loss. Conventional tissue engineering approaches have been developed to regenerate or repair periodontium but, engineered periodontal tissue formation is still challenging because there are still limitations to control spatial compartmentalization for individual tissues and provide optimal 3D constructs for tooth-supporting tissue regeneration and maturation. Here, we present the recently developed strategies to induce osteogenesis and cementogenesis by the fabrication of 3D architectures or the chemical modifications of biopolymeric materials. These techniques in tooth-supporting hard tissue engineering are highly promising to promote the periodontal regeneration and advance the interfacial tissue formation for tissue integrations of PDL fibrous connective tissue bundles (alveolar bone-to-PDL or PDL-to-cementum) for functioning restorations of the periodontal complex.

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Brodland, G. Wayne. "The Differential Interfacial Tension Hypothesis (DITH): A Comprehensive Theory for the Self-Rearrangement of Embryonic Cells and Tissues." Journal of Biomechanical Engineering 124, no. 2 (March 29, 2002): 188–97. http://dx.doi.org/10.1115/1.1449491.

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A comprehensive theory, herein named the Differential Interfacial Tension Hypothesis (DITH), for the self-rearrangement of embryonic cells and tissues is presented. These rearrangements include sorting, mixing and formation of checkerboard patterns in heterotypic aggregates of embryonic cells, and total or partial engulfment, separation and dissociation of tissues. This broadly-based theory accounts for the action of all currently known cytoskeletal components and cell adhesion mechanisms. The theory is used to derive conditions for the cell and tissue rearrangements named above. Finite element-based computer simulations involving two or more cell types confirm these conditions.

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Zhao, Pengchao, Kongchang Wei, Qian Feng, Heng Chen, Dexter Siu Hong Wong, Xiaoyu Chen, Chia-Ching Wu, and Liming Bian. "Mussel-mimetic hydrogels with defined cross-linkers achieved via controlled catechol dimerization exhibiting tough adhesion for wet biological tissues." Chemical Communications 53, no. 88 (2017): 12000–12003. http://dx.doi.org/10.1039/c7cc07215e.

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17

Wu, W., and G. H. Nancollas. "The Relationship between Surface Free-Energy and Kinetics in the Mineralization and Demineralization of Dental Hard Tissue." Advances in Dental Research 11, no. 4 (November 1997): 566–75. http://dx.doi.org/10.1177/08959374970110042601.

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The interfacial free-energy is an important factor in the regulation of mineralization and dissolution at the surfaces of dental hard tissues. However, few thermodynamic studies have been aimed at the elucidation of the interfacial terms. Contact angle measurements (sessile drop and thin layer wicking) and kinetic dissolution and growth techniques have been used to study the interfacial properties of root dentin (D), human enamel (E), and hydroxyapatite (HAP). The interfacial tensions between water (w) and each of these phases were calculated from contact angle data according to surface tension components theory. The values γwD = 4.5 x 10-3J m-2, γ wE = 8.8 x 10-3J m-2, and γw,HAP = 10.4 x 10-3J m-2 were of the same order of magnitude as those obtained from dissolution kinetic data (pH = 4.5): γwD = 1.4 x 10-3J m-2, γwE = 3.2 x 10-3J m-2, and γwHAP = 9.3 x 10-3J m-2. Kinetics studies of the crystallization of HAP on HAP, dentin, and enamel yielded the interfacial free-energy values, γwHAP = 17.1 x 10-3J m-2, 17.7 x 10-3J m-2, and 9.4 x 10-3J m-2, respectively, probably reflecting the interfacial energies of the deposited phases rather than those of the dental hard-tissue substrata. The lower interfacial tension values are consistent with the higher solubilities of these solid phases: logKso = -52.0, -55 - 57, and -58 - 59, for root dentin, enamel, and HAP, respectively, expressed as an equivalent HAP ionic product. The higher interfacial free-energy is also consistent with the slower mineralization of HAP on dentin and enamel surfaces.

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Peppas, Nikolaos A., and Pierre A. Buri. "Surface, interfacial and molecular aspects of polymer bioadhesion on soft tissues." Journal of Controlled Release 2 (November 1985): 257–75. http://dx.doi.org/10.1016/0168-3659(85)90050-1.

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Ma, Zhenwei, Zhen Yang, Qiman Gao, Guangyu Bao, Amin Valiei, Fan Yang, Ran Huo, et al. "Bioinspired tough gel sheath for robust and versatile surface functionalization." Science Advances 7, no. 15 (April 2021): eabc3012. http://dx.doi.org/10.1126/sciadv.abc3012.

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Sutures pervade surgeries, but their performance is limited by the mechanical mismatch with tissues and the lack of advanced functionality. Existing modification strategies result in either deterioration of suture’s bulk properties or a weak coating susceptible to rupture or delamination. Inspired by tendon endotenon sheath, we report a versatile strategy to functionalize fiber-based devices such as sutures. This strategy seamlessly unites surgical sutures, tough gel sheath, and various functional materials. Robust modification is demonstrated with strong interfacial adhesion (>2000 J m−2). The surface stiffness, friction, and drag of the suture when interfacing with tissues can be markedly reduced, without compromising the tensile strength. Versatile functionalization of the suture for infection prevention, wound monitoring, drug delivery, and near-infrared imaging is then presented. This platform technology is applicable to other fiber-based devices and foreseen to affect broad technological areas ranging from wound management to smart textiles.

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Galindo, Tania Guadalupe Peñaflor, Yadong Chai, and Motohiro Tagaya. "Hydroxyapatite Nanoparticle Coating on Polymer for Constructing Effective Biointeractive Interfaces." Journal of Nanomaterials 2019 (January 3, 2019): 1–23. http://dx.doi.org/10.1155/2019/6495239.

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Bone is an organic-inorganic composite with the ability to regenerate itself. Thus, several studies based on artificial organic-inorganic interface sciences have been tried to develop capable materials for effective regenerative bone tissues. Hydroxyapatite nanoparticles (HAp NPs) have extensively been researched in bone tissue engineering due to the compositional and shape similarity to the mineral bone and excellent biocompatibility. However, HAp alone has low mechanical strength, which limits its applications. Therefore, HAp NPs have been deposited on the biocompatible polymer matrix, obtaining composites with the enhanced mechanical, thermal, and rheological properties and with higher biocompatibility and bioactivity. For developing new biomedical applications, polymer-HAp interfacial interactions that provide biofusion should be investigated. This paper reviewed common coating techniques for obtaining HAp NPs/polymer fusion interfaces as well as in vitro studies of interfacial interactions with proteins and cells, demonstrating better biocompatibility. Studies based on interfacial interactions between biomolecules and HAp NPs were highlighted, and how these interactions can be affected by specific protein preadsorption was also summarized.

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Peng, Xin, Xianfeng Xia, Xiayi Xu, Xuefeng Yang, Boguang Yang, Pengchao Zhao, Weihao Yuan, Philip Wai Yan Chiu, and Liming Bian. "Ultrafast self-gelling powder mediates robust wet adhesion to promote healing of gastrointestinal perforations." Science Advances 7, no. 23 (June 2021): eabe8739. http://dx.doi.org/10.1126/sciadv.abe8739.

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Achieving strong adhesion of bioadhesives on wet tissues remains a challenge and an acute clinical demand because of the interfering interfacial water and limited adhesive-tissue interactions. Here we report a self-gelling and adhesive polyethyleneimine and polyacrylic acid (PEI/PAA) powder, which can absorb interfacial water to form a physically cross-linked hydrogel in situ within 2 seconds due to strong physical interactions between the polymers. Furthermore, the physically cross-linked polymers can diffuse into the substrate polymeric network to enhance wet adhesion. Superficial deposition of PEI/PAA powder can effectively seal damaged porcine stomach and intestine despite excessive mechanical challenges and tissue surface irregularities. We further demonstrate PEI/PAA powder as an effective sealant to enhance the treatment outcomes of gastric perforation in a rat model. The strong wet adhesion, excellent cytocompatibility, adaptability to fit complex sites, and easy synthesis of PEI/PAA powder make it a promising bioadhesive for numerous biomedical applications.

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Pearsall, Allan D., Robert Spears, and Kimberly Sarubbi. "The interfacial behavior of hard tissue replacement as revealed by SEM." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 3 (August 12, 1990): 854–55. http://dx.doi.org/10.1017/s0424820100161837.

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INTRODUCTION:Hard Tissue Replacement (HTR) has been postulated to be an effective implant material for bone reconstruction and maintenance. HTR consists of a polymethylmethacrylate core coated with polyhydroxyethylmethacrylate and has been demonstrated in light microscopic studies to attach directly to bone. The present study was performed to add to the available information by investigating the interfacial bonding of this polymer using scanning electron microscopy.MATERIALS AND METHODS: Twenty Sprague-Dawley rats were anesthetized, a midline scalp incision was made to expose the calvaria and the periosteum reflected. Trephine defects were prepared by excising a 1 x 2-mm section of bone and the HTR polymer (24 mesh) inserted. The skin and periosteum were reapproximated and the incision closed. Pursuant to vascular perfusion with a mixture of aldehydes, the implants and surrounding tissue were extirpated in situ after 7-, 14-, 28-, and 56-day observation periods. Tissues were then washed in buffer, dehydrated, fractured in liquid nitrogen and dried in Freon. The samples were viewed in a JEOL JSM35CF SEM with x-ray energy dispersive analysis (EDXA).

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Liu, Huanrong, Xiaoqing Wang, Xiubiao Zhang, Zhengjun Sun, and Zehui Jiang. "In situ detection of the fracture behaviour of moso bamboo (Phyllostachys pubescens) by scanning electron microscopy." Holzforschung 70, no. 12 (December 1, 2016): 1183–90. http://dx.doi.org/10.1515/hf-2016-0003.

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Abstract The remarkable fracture toughness of bamboo culms is highly attributed to the proper embedding of the stiff fibre caps of the vascular bundles into the soft parenchyma matrix. In this study, the fracture behaviour of small specimens of moso bamboo (Phyllostachys pubescens) in tension and bending were investigated in situ with a scanning electron microscope (SEM) to visualise crack initiation and propagation within bamboo tissues and its interactions with the structural components (fibres and parenchyma tissues). Fracture surfaces were studied by field-emission SEM. The fracture of bamboo in either tension or bending was non-catastrophic, and cracks propagated in a tortuous manner with massive interfacial delamination. The stiff fibre bundles played an important role in restraining crack propagation, acting as bridges to inhibit cracks opening and also as “crack stoppers” inducing extensive crack-deflections. Microstructural analysis of the fractured surfaces revealed that substantial interfacial debonding, sliding and fibre pull-outs occurred at various length scales, which are believed to be effective in dissipating the crack energy. The synergistic effects of crack-deflection, crack-bridging and interfacial debonding are regarded to be mainly responsible for the remarkable fracture toughness of bamboo.

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Park, Chan Ho. "Prototype Development for the Periodontal Model System with the Spatial Compartmentalization by the Additive Manufacturing." Applied Sciences 9, no. 21 (November 4, 2019): 4687. http://dx.doi.org/10.3390/app9214687.

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At present, various tissue engineering strategies have been developed for multiple tissue regeneration and integrative structure formations. However, the regenerations of tooth-supportive structures are still limited and challenging due to the micro-interfacial compartmentalization of multiple tissues, their integrations for systematic responses, and spatiotemporal organizations of engineered tissues. Here, we investigated the scaffold prototype as the regeneration platform of the periodontal complex (cementum-periodontal ligament (PDL)-bone). Based on the tooth image dataset, the prototype scaffold was designed with individual periodontal tissues while using the three-dimensional (3D) printing technique and solvent-casting method with poly-ε-caprolactone (PCL). The architecture was characterized by scanning electron microscope (SEM) and biological assessments were performed with human periodontal ligament (hPDL) cells by confocal microscope. In particular, the angulations and deformations of hPDL cells on PDL architectures were analyzed while using nuclear aspect ratio (NAR = 2.319 ± 0.273) and nuclear shape index (NSI (circularity) = 0.546 ± 0.0273). In in-vitro, designed surface microgroove patterns facilitated angular organizations of hPDL cells (frequency of 0–10° angulations = 75 ± 9.54 out of 97.3 ± 2.52) for seven days. The prototype scaffolding system showed geometric adaptation to the digitized image dataset, hPDL orientations on microgroove-patterned surface, and architectural compartmentalizations for periodontal tissue regeneration.

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Lin, Daniel, Qing Li, Wei Li, Ionut Ichim, and Michael Swain. "Damage Evaluation of Bone Tissues with Dental Implants." Key Engineering Materials 348-349 (September 2007): 905–8. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.905.

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Dental implants have been extensively used in prosthetic dentistry over the last two decades. Clinical experience shows that the healing and osseointegration process can heavily influence the success of the implantation. It is critical to understand the damage extent in different time frames. This paper aims at exploring the mechanical damage of dental implantation over the healing process. The 3D finite element analysis (FEA) models were developed based on computerised tomography (CT) scan technology to investigate the load-induced damage of interfacial osseointegration, as well as cortical and cancellous bone tissues. Unlike the existing linear finite element (FE) stress analysis, this study takes into account the damage accumulation and micro-crack nucleation under a framework of bone/interface remodelling. This study reveals the damage in the surrounding bone tissues and bone-implant interfaces at different stages of the healing process, and consequently premature load tolerances are suggested.

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Pocivavsek, Luka, Ann Junghans, Noureddine Zebda, Konstantin Birukov, and Jaroslaw Majewski. "Tuning endothelial monolayer adhesion: a neutron reflectivity study." American Journal of Physiology-Lung Cellular and Molecular Physiology 306, no. 1 (January 1, 2014): L1—L9. http://dx.doi.org/10.1152/ajplung.00160.2013.

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Endothelial cells, master gatekeepers of the cardiovascular system, line its inner boundary from the heart to distant capillaries constantly exposed to blood flow. Interendothelial signaling and the monolayers adhesion to the underlying collagen-rich basal lamina are key in physiology and disease. Using neutron scattering, we report the first ever interfacial structure of endothelial monolayers under dynamic flow conditions mimicking the cardiovascular system. Endothelial adhesion (defined as the separation distance ℓ between the basal cell membrane and solid boundary) is explained using developed interfacial potentials and intramembrane segregation of specific adhesion proteins. Our method provides a powerful tool for the biophysical study of cellular layer adhesion strength in living tissues.

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Jabłoński, Miroslaw, Vladimir M. Gun’ko, Alina P. Golovan, Roman Leboda, Jadwiga Skubiszewska-Zięba, Ryszard Pluta, and Vladimir V. Turov. "Textural characteristics of model and natural bone tissues and interfacial behavior of bound water." Journal of Colloid and Interface Science 392 (February 2013): 446–62. http://dx.doi.org/10.1016/j.jcis.2012.08.070.

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Sitterle, Valerie B., Wei Sun, and Marc E. Levenston. "A modified lap test to more accurately estimate interfacial shear strength for bonded tissues." Journal of Biomechanics 41, no. 15 (November 2008): 3260–64. http://dx.doi.org/10.1016/j.jbiomech.2008.09.006.

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Ford, Robert C., Stuart V. Ruffle, Anibal J. Ramirez-Cuesta, Ilias Michalarias, Ilir Beta, Aline Miller, and Jichen Li. "Inelastic Incoherent Neutron Scattering Measurements of Intact Cells and Tissues and Detection of Interfacial Water." Journal of the American Chemical Society 126, no. 14 (April 2004): 4682–88. http://dx.doi.org/10.1021/ja0393269.

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Singh, Milind, Nathan Dormer, Jean R. Salash, Jordan M. Christian, David S. Moore, Cory Berkland, and Michael S. Detamore. "Three-dimensional macroscopic scaffolds with a gradient in stiffness for functional regeneration of interfacial tissues." Journal of Biomedical Materials Research Part A 9999A (2010): NA. http://dx.doi.org/10.1002/jbm.a.32765.

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HE, YING, and RYUTARO HIMENO. "FINITE ELEMENT ANALYSIS ON FLUID FILTRATION IN SYSTEM OF PERMEABLE CURVED CAPILLARY AND TISSUE." Journal of Mechanics in Medicine and Biology 12, no. 04 (September 2012): 1250077. http://dx.doi.org/10.1142/s0219519412005101.

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Fluid filtration across a capillary wall, which is associated with many diseases, is noteworthy for its significant role in cancer treatment. In this study, the coupled fluid dynamic phenomenon within a capillary and its surrounding tissues has been numerically analyzed in order to investigate the effect of capillary geometry, filtration coefficient, and tissue pressure on capillary filtration. The computational domain is composed of a fluid capillary subdomain coupled with a porous tissue subdomain. The flows in the sub-domains are described by the Stokes and Darcy equations, respectively, which are solved in a coupled manner by applying a nodal replacement scheme at the capillary wall. Distributions of pressure and flow velocity are presented, which show that the interfacial pressure drop is strongly influenced by permeability, tissue boundary pressure, and capillary radii. These results provide useful information on the relationship between the interstitial flow pattern and oxygen transport.

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Shajrawi, I., M. Luria, D. G. Mendes, and J. H. Boss. "Necrotizing Granulomas within the Periprosthetic Tissues of Cemented and Cementless Total Arthroplasties." Veterinary and Comparative Orthopaedics and Traumatology 08, no. 02 (1995): 107–13. http://dx.doi.org/10.1055/s-0038-1632438.

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Necrotizing granulomas were found in the pseudocapsule or interfacial membrane of two patients with an aseptically loosened cemented total hip arthroplasty and in one patient with an aseptically loosened cementless knee arthroplasty. The environs of the necrotizing granulomas disclosed prosthetic debris-induced foreign body granulomatous, chronic inflammatory and cicatrizing changes. Particulate breakdown products of polyethylene and finely dispersed metallic particles were present in the necrotic core, stroma and macrophages of the necrotizing granulomas. A review of the literature and the authors’ personal experience attests to the rarity of such granulomas in the periprosthetic tissues. Polyethylene being non-antigenic, it is suggested that an allergic-pathergic reaction to metallic ions released in loco from the prosthesis itself, from the deposited metallic wear particles or from both accounts for the development of the necrotizing granulomas.

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Fujiwara, Shougo, Kan Shoji, Chiho Watanabe, Ryuji Kawano, and Miho Yanagisawa. "Microfluidic Formation of Honeycomb-Patterned Droplets Bounded by Interface Bilayers via Bimodal Molecular Adsorption." Micromachines 11, no. 7 (July 20, 2020): 701. http://dx.doi.org/10.3390/mi11070701.

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Assembled water-in-oil droplets bounded by lipid bilayers are used in synthetic biology as minimal models of cell tissue. Microfluidic devices successfully generate monodispersed droplets and assemble them via droplet interface bilayesr (DIB) formation. However, a honeycomb pattern of DIB-bounded droplets, similar to epithelial tissues, remains unrealized because the rapid DIB formation between the droplets hinders their ability to form the honeycomb pattern. In this paper, we demonstrate the microfluidic formation of a honeycomb pattern of DIB-bounded droplets using two surfactants with different adsorption rates on the droplet surface. A non-DIB forming surfactant (sorbitan monooleate, Span 80) was mixed with a lipid (1,2-dioleoyl-sn-glycero-3-phosphocholine, PC), whose adsorption rate on the droplet surface and saturated interfacial tension were lower than those of Span 80. By changing the surfactant composition, we established the conditions under which the droplets initially form a honeycomb pattern and subsequently adhere to each other via DIB formation to minimize the interfacial energy. In addition, the reconstituted membrane protein nanopores at the DIBs were able to transport molecules. This new method, using the difference in the adsorption rates of two surfactants, allows the formation of a honeycomb pattern of DIB-bounded droplets in a single step, and thus facilitates research using DIB-bounded droplet assemblies.

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Liu, Jun, Katie E. Gunnison, Mehmet Sarikaya, and Ilhan A. Aksay. "A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 2 (August 1992): 1024–25. http://dx.doi.org/10.1017/s0424820100129759.

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The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

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Murphy, Meghan K., Boaz Arzi, Shannon M. Prouty, Jerry C. Hu, and Kyriacos A. Athanasiou. "Neocartilage integration in temporomandibular joint discs: physical and enzymatic methods." Journal of The Royal Society Interface 12, no. 103 (February 2015): 20141075. http://dx.doi.org/10.1098/rsif.2014.1075.

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Integration of engineered musculoskeletal tissues with adjacent native tissues presents a significant challenge to the field. Specifically, the avascularity and low cellularity of cartilage elicit the need for additional efforts in improving integration of neocartilage within native cartilage. Self-assembled neocartilage holds significant potential in replacing degenerated cartilage, though its stabilization and integration in native cartilage require further efforts. Physical and enzymatic stabilization methods were investigated in an in vitro model for temporomandibular joint (TMJ) disc degeneration. First, in phase 1, suture, glue and press-fit constructs were compared in TMJ disc intermediate zone defects. In phase 1, suturing enhanced interfacial shear stiffness and strength immediately; after four weeks, a 15-fold increase in stiffness and a ninefold increase in strength persisted over press-fit. Neither suture nor glue significantly altered neocartilage properties. In phase 2, the effects of the enzymatic stabilization regimen composed of lysyl oxidase, CuSO 4 and hydroxylysine were investigated. A full factorial design was employed, carrying forward the best physical method from phase 1, suturing. Enzymatic stabilization significantly increased interfacial shear stiffness after eight weeks. Combined enzymatic stabilization and suturing led to a fourfold increase in shear stiffness and threefold increase in strength over press-fit. Histological analysis confirmed the presence of a collagen-rich interface. Enzymatic treatment additionally enhanced neocartilage mechanical properties, yielding a tensile modulus over 6 MPa and compressive instantaneous modulus over 1200 kPa at eight weeks. Suturing enhances stabilization of neocartilage, and enzymatic treatment enhances functional properties and integration of neocartilage in the TMJ disc. Methods developed here are applicable to other orthopaedic soft tissues, including knee meniscus and hyaline articular cartilage.

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Kumar, P., and K. N. Rai. "Numerical solution of generalized DPL model using wavelet method during thermal therapy applications." International Journal of Biomathematics 12, no. 03 (April 2019): 1950032. http://dx.doi.org/10.1142/s1793524519500323.

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In this paper, generalized dual-phase-lag (DPL) model has been studied for the numerical analysis of spatial variation of temperature within living biological tissues during thermal therapy applications. A new hybrid numerical scheme based on finite difference scheme and Chebyshev wavelet Galerkin method are used to solve the generalized DPL model with constant heat flux boundary condition. Multi-resolution and multi-scale computational property of Chebyshev wavelet in the present case localizes small scale variations of solution and fast switching of functional bases. Our study demonstrates that due to presence of coupling factor (convection–perfusion), generalized DPL model predicts lower temperature than classical DPL and Pennes model at the tumor position. Higher values of phase lag times results in lower temperature at the tumor position. But, in case of variation of phase lag time due to temperature gradient, the nature of temperature profile also depends on the spatial coordinate. The effect of the blood temperature, porosity and interfacial convective heat transfer on temperature distribution has been investigated. It is found that larger values of porosity and interfacial convective heat transfer results in lower temperature at the tumor position. Also, both porosity and interfacial convective heat transfer are pronounced more at higher values. The whole analysis is presented in dimensionless form.

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Chiesa, Irene, Gabriele Maria Fortunato, Anna Lapomarda, Licia Di Pietro, Francesco Biagini, Aurora De Acutis, Luca Bernazzani, Maria Rosaria Tinè, Carmelo De Maria, and Giovanni Vozzi. "Ultrasonic mixing chamber as an effective tool for the biofabrication of fully graded scaffolds for interface tissue engineering." International Journal of Artificial Organs 42, no. 10 (June 16, 2019): 586–94. http://dx.doi.org/10.1177/0391398819852960.

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One of the main challenges of the interface-tissue engineering is the regeneration of diseased or damaged interfacial native tissues that are heterogeneous both in composition and in structure. In order to achieve this objective, innovative fabrication techniques have to be investigated. This work describes the design, fabrication, and validation of a novel mixing system to be integrated into a double-extruder bioprinter, based on an ultrasonic probe included into a mixing chamber. To validate the quality and the influence of mixing time, different nanohydroxyapatite–gelatin samples were printed. Mechanical characterization, micro-computed tomography, and thermogravimetric analysis were carried out. Samples obtained from three-dimensional bioprinting using the mixing chamber were compared to samples obtained by deposition of the same final solution obtained by manually operated ultrasound probe, showing no statistical differences. Results obtained from samples characterization allow to consider the proposed mixing system as a promising tool for the fabrication of graduated structures which are increasingly being used in interface-tissue engineering.

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Donnelly, Hannah, Carol-Anne Smith, Paula E. Sweeten, Nikolaj Gadegaard, RM Dominic Meek, Matteo D’Este, Alvaro Mata, David Eglin, and Matthew J. Dalby. "Bone and cartilage differentiation of a single stem cell population driven by material interface." Journal of Tissue Engineering 8 (January 1, 2017): 204173141770561. http://dx.doi.org/10.1177/2041731417705615.

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Adult stem cells, such as mesenchymal stem cells, are a multipotent cell source able to differentiate towards multiple cell types. While used widely in tissue engineering and biomaterials research, they present inherent donor variability and functionalities. In addition, their potential to form multiple tissues is rarely exploited. Here, we combine an osteogenic nanotopography and a chondrogenic hyaluronan hydrogel with the hypothesis that we can make a complex tissue from a single multipotent cell source with the exemplar of creating a three-dimensional bone–cartilage boundary environment. Marrow stromal cells were seeded onto the topographical surface and the temperature gelling hydrogel laid on top. Cells that remained on the nanotopography spread and formed osteoblast-like cells, while those that were seeded into or migrated into the gel remained rounded and expressed chondrogenic markers. This novel, simple interfacial environment provides a platform for anisotropic differentiation of cells from a single source, which could ultimately be exploited to sort osteogenic and chondrogenic progenitor cells from a marrow stromal cell population and to develop a tissue engineered interface.

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Peddireddy, Karthik, Simon Čopar, Khoa V. Le, Igor Muševič, Christian Bahr, and Venkata S. R. Jampani. "Self-shaping liquid crystal droplets by balancing bulk elasticity and interfacial tension." Proceedings of the National Academy of Sciences 118, no. 14 (March 31, 2021): e2011174118. http://dx.doi.org/10.1073/pnas.2011174118.

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The shape diversity and controlled reconfigurability of closed surfaces and filamentous structures, universally found in cellular colonies and living tissues, are challenging to reproduce. Here, we demonstrate a method for the self-shaping of liquid crystal (LC) droplets into anisotropic and three-dimensional superstructures, such as LC fibers, LC helices, and differently shaped LC vesicles. The method is based on two surfactants: one dissolved in the LC dispersed phase and the other in the aqueous continuous phase. We use thermal stimuli to tune the bulk LC elasticity and interfacial energy, thereby transforming an emulsion of polydispersed, spherical nematic droplets into numerous, uniform-diameter fibers with multiple branches and vice versa. Furthermore, when the nematic LC is cooled to the smectic-A LC phase, we produce monodispersed microdroplets with a tunable diameter dictated by the cooling rate. Utilizing this temperature-controlled self-shaping of LCs, we demonstrate life-like smectic LC vesicle structures analogous to the biomembranes in living systems. Our experimental findings are supported by a theoretical model of equilibrium interface shapes. The shape transformation is induced by negative interfacial energy, which promotes a spontaneous increase of the interfacial area at a fixed LC volume. The method was successfully applied to many different LC materials and phases, demonstrating a universal mechanism for shape transformation in complex fluids.

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Reyes-Carmona DDS, MSD, PhD, Jessie, Adair Santos PhD, and Mabel Cordeiro DDS, PhD. "Mineral Trioxide Aggregate and Calcium Hydroxide Promotes In Vivo Intratubular Mineralization." Odovtos - International Journal of Dental Sciences 18, no. 1 (March 17, 2016): 49. http://dx.doi.org/10.15517/ijds.v18i1.23548.

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Literature showed that the interaction of Mineral Trioxide Aggregate (MTA) with dentin in phosphate-buffered saline (PBS) promotes a biomineralization process that leads to the formation of an interfacial layer with mineralized structures at the cement-dentin interface. Thus, we investigated the in vivo biomineralization process promoted by MTA and Ca(OH)² with dentin. Human dentin tubes filled with ProRoot MTA, Ca(OH)² or kept empty were implanted in subcutaneous tissues in the back of mice. After 12h, 1, 3, 7, 15, 30 and 60 days, the dentin tubes were processed for Scanning Electron Microscope (SEM) observations. SEM examination showed the presence of apatite-like clusters on collagen fibrils over the surface of tubes containing the biomaterials. This mineral deposition was more extensive and compact through time. At day 7, a compact layer of apatite was formed. The MTA/Ca(OH)² -dentin interface showed intratubular mineralization as early as 12h post-implantation. MTA and Ca(OH)² in an in vivo environment promoted a biomineralization process with dentin, simultaneously to the acute inflammatory response. MTA triggered an earlier and denser interfacial layer.

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Wiertlewski, Michaël, Rebecca Fenton Friesen, and J. Edward Colgate. "Partial squeeze film levitation modulates fingertip friction." Proceedings of the National Academy of Sciences 113, no. 33 (August 1, 2016): 9210–15. http://dx.doi.org/10.1073/pnas.1603908113.

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When touched, a glass plate excited with ultrasonic transverse waves feels notably more slippery than it does at rest. To study this phenomenon, we use frustrated total internal reflection to image the asperities of the skin that are in intimate contact with a glass plate. We observed that the load at the interface is shared between the elastic compression of the asperities of the skin and a squeeze film of air. Stroboscopic investigation reveals that the time evolution of the interfacial gap is partially out of phase with the plate vibration. Taken together, these results suggest that the skin bounces against the vibrating plate but that the bounces are cushioned by a squeeze film of air that does not have time to escape the interfacial separation. This behavior results in dynamic levitation, in which the average number of asperities in intimate contact is reduced, thereby reducing friction. This improved understanding of the physics of friction reduction provides key guidelines for designing interfaces that can dynamically modulate friction with soft materials and biological tissues, such as human fingertips.

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Siar, Chong Huat, Chooi Gait Toh, Georgios E. Romanos, and Kok Han Ng. "Comparative assessment of the interfacial soft and hard tissues investing implants and natural teeth in the macaque mandible." Clinical Oral Investigations 19, no. 6 (November 21, 2014): 1353–62. http://dx.doi.org/10.1007/s00784-014-1362-7.

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Nowlin, John, Mehzubh A. Bismi, Baptiste Delpech, Patrick Dumas, Yingge Zhou, and George Z. Tan. "Engineering the hard–soft tissue interface with random-to-aligned nanofiber scaffolds." Nanobiomedicine 5 (January 1, 2018): 184954351880353. http://dx.doi.org/10.1177/1849543518803538.

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Tendon injuries can be difficult to heal and have high rates of relapse due to stress concentrations caused by scar formation and the sutures used in surgical repair. Regeneration of the tendon/ligament-to-bone interface is critical to provide functional graft integration after injury. The objective of this study is to recreate the tendon-to-bone interface using a gradient scaffold which is fabricated by a one-station electrospinning process. Two cell phenotypes were grown on a poly- ε-caprolactone nanofiber scaffold which possesses a gradual transition from random to aligned nanofiber patterns. We assessed the effects of the polymer concentration, tip-to-collector distance, and electrospinning time on the microfiber diameter and density. Osteosarcoma and fibroblast cells were seeded on the random and aligned sections of scaffolds, respectively. A random-to-aligned cocultured tissue interface which mimicked the native transition in composition of enthesis was created after 96 h culturing. The results showed that the microstructure gradient influenced the cell morphology, tissue topology, and promoted enthesis formation. This study demonstrates a heterogeneous nanofiber scaffold strategy for interfacial tissue regeneration. It provides a potential solution for mimicking transitional interface between distinct tissues, and can be further developed as a heterogeneous cellular composition platform to facilitate the formation of multi-tissue complex systems.

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Dutta, Sayan Deb, Dinesh K. Patel, Yu-Ri Seo, Chan-Woo Park, Seung-Hwan Lee, Jin-Woo Kim, Jangho Kim, Hoon Seonwoo, and Ki-Taek Lim. "In Vitro Biocompatibility of Electrospun Poly(ε-Caprolactone)/Cellulose Nanocrystals-Nanofibers for Tissue Engineering." Journal of Nanomaterials 2019 (October 15, 2019): 1–11. http://dx.doi.org/10.1155/2019/2061545.

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Cellulose nanocrystals (CNCs) have emerged as promising materials for the fabrication of micro/nanoplatforms that can replace tissues more effectively. CNCs offer interesting properties that facilitate the enhancement of polymer properties. Cytotoxicity of rice husk-derived CNCs was evaluated through WST-1 assay in the presence of human mesenchymal stem cells. Electrospinning technique was used to fabricate nanofibers of poly-ε-caprolactone and its composites. Significant improvement in the mechanical property was observed in the composites relative to the pure polymer. This improvement was attributed to the better interfacial interactions between the polymer matrix and CNCs. Notably, better cell viability and differentiation were observed with the composite nanofibers than with the pure polymers. The osteogenic potential of the fabricated nanofibers was assessed by alizarin red S staining and real-time PCR. Enhanced mineralization occurred in the presence of the composite rather than pure polymer nanofibers. Furthermore, the higher levels of osteogenic markers observed with the media containing the composites clearly indicated their osteogenic potential. These results suggested that fabricated composites have the potential to be used as a biomaterial for tissue engineering applications.

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Spilker, Robert L., Jun-Kyo Suh, and Van C. Mow. "Effects of Friction on the Unconfined Compressive Response of Articular Cartilage: A Finite Element Analysis." Journal of Biomechanical Engineering 112, no. 2 (May 1, 1990): 138–46. http://dx.doi.org/10.1115/1.2891164.

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A finite element analysis is used to study a previously unresolved issue of the effects of platen-specimen friction on the response of the unconfined compression test; effects of platen permeability are also determined. The finite element formulation is based on the linear KLM biphasic model for articular cartilage and other hydrated soft tissues. A Galerkin weighted residual method is applied to both the solid phase and the fluid phase, and the continuity equation for the intrinsically incompressible binary mixture is introduced via a penalty method. The solid phase displacements and fluid phase velocities are interpolated for each element in terms of unknown nodal values, producing a system of first order differential equations which are solved using a standard numerical finite difference technique. An axisymmetric element of quadrilateral cross-section is developed and applied to the mechanical test problem of a cylindrical specimen of soft tissue in unconfined compression. These studies show that interfacial friction plays a major role in the unconfined compression response of articular cartilage specimens with small thickness to diameter ratios.

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Park, Sunghee E., Andrei Georgescu, Jeong Min Oh, Keon Woo Kwon, and Dongeun Huh. "Polydopamine-Based Interfacial Engineering of Extracellular Matrix Hydrogels for the Construction and Long-Term Maintenance of Living Three-Dimensional Tissues." ACS Applied Materials & Interfaces 11, no. 27 (June 14, 2019): 23919–25. http://dx.doi.org/10.1021/acsami.9b07912.

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Bisegna, Paolo, and Federica Caselli. "A simple formula for the effective complex conductivity of periodic fibrous composites with interfacial impedance and applications to biological tissues." Journal of Physics D: Applied Physics 41, no. 11 (May 8, 2008): 115506. http://dx.doi.org/10.1088/0022-3727/41/11/115506.

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Li, Xingguo, Bingbing An, and Dongsheng Zhang. "Effect of Interfacial Properties on the Mechanical Behavior of Bone-Like Materials: A Numerical Study." International Journal of Applied Mechanics 09, no. 01 (January 2017): 1750014. http://dx.doi.org/10.1142/s1758825117500144.

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Interfacial behavior in the microstructure and the plastic deformation in the protein matrix influence the overall mechanical properties of biological hard tissues. A cohesive finite element model has been developed to investigate the inelastic mechanical properties of bone-like biocomposites consisting of hard mineral crystals embedded in soft biopolymer matrix. In this study, the complex interaction between plastic dissipation in the matrix and bonding properties of the interface between minerals and matrix is revealed, and the effect of such interaction on the toughening of bone-like biocomposites is identified. For the case of strong and intermediate interfaces, the toughness of biocomposites is controlled by the post yield behavior of biopolymer; the matrix with low strain hardening can undergo significant plastic deformation, thereby promoting enhanced fracture toughness of biocomposites. For the case of weak interfaces, the toughness of biocomposites is governed by the bonding property of the interface, and the post-yield behavior of biopolymer shows negligible effect on the toughness. The findings of this study help to direct the path for designing bioinspired materials with superior mechanical properties.

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Ish-Shalom, Z., I. Misselevich, D. G. Mendes, and J. H. Boss. "Foreign Body Granulomatous Response to Particulate Bony Debris." Veterinary and Comparative Orthopaedics and Traumatology 09, no. 03 (July 1996): 119–25. http://dx.doi.org/10.1055/s-0038-1632516.

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SummaryArchival material was retrieved in order to histologically assess the body’s response to micron-sized, necrotic bony particles. Specimens were obtained from (1) human bone grafts in a subcutaneous or muscular pouch of athymic nude mice, (2) a massive bone allograft replacing a patient’s humerus, (3) rabbits’ healing tibial cortical bone defects littered with finely dispersed bony particles, (4) periprosthetic tissues of patient’s aseptically loosened artificial joints and (5) interfacial membranes of intramedullary nails used for fixation of patients’ fractured long bones. Necrotic bony debris was found to induce a giant celled granulomatous reaction. In sections of undecalcified samples stained by the von Kossa method, small calcific particles were observed to be present within polykaryonic macrophages (foreign body giant cells) and surrounded by mononuclear macrophages. It is concluded that a foreign body-type giant celled granulation tissue participates in the degradation of micron-sized, necrotic bony detritus, whether the disintegrating bone is of the xeno-, alio- or autogenic provenance.Histological examination of von Kossa-stained sections, of undecalcified specimens, revealed a giant celled granulomatous response to bony debris. Irrespective of whether or not the disintegrating bone was of auto-, alio- or xenogeneic provenance, micron-sized bony particles were found to be phagocytosed by polykaryonic macrophages of the granulation tissue.

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Petrovic, Bojan, Dejan Markovic, and Danka Filipovic. "Prophylactic efficiency of glass-ionomer fissure sealant." Chemical Industry 61, no. 2 (2007): 90–95. http://dx.doi.org/10.2298/hemind0702090p.

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One of the most efficient prophylactic measures in caries prevention is sealing pits and fissures. After improvements of physical and mechanical properties, glass-ionomers are frequently used as sealing materials. The aim of this study was to evaluate the prophylactic efficiency of Fuji VII, a glass-ionomer fissure sealant, through adaptation ability and fluoride reeasing potential assessment using scanning electron microscopic and energy dispersive spectroscopic techniques. The sample consisted of 20 extracted intact human teeth, 10 premolars and 10 molars. Six sections of each tooth were analyzed using SEM. EDS analysis was conducted one week and three months after material placement. The parameters used for the evaluation included: adaptation ability, penetration depth, material structure, integrity of the interfacial zone and ion exchange extent. The sealant penetration depth was observed at 30 X magnification, and the interfacial zone between the material and the enamel at 500-10000 X. EDS was used for quantitative analysis of the material structure, interfacial zone and the enamel surface. The results were statistically analyzed the using chisquare test and descriptive statistical methods. SEM analysis revealed the zone of interaction between the enamel surface and the glass-ionomer with predominant cohesive failures within the sealant material, and satisfactory adaptation ability of the sealing material. The mean value of the penetration was 83% of the total fissure depth, without a statistically significant difference between the tested teeth groups. A lower penetration ability was observed in deep pits and fissures with a larger diameter of unfilled space (p<0.05). EDS analysis revealed the potential of the glass-ionomer for ion exchange with dental tissues. The presence of fluoride ions was detected in 2 sections 3 months after material placement. Glass-ionomers, chemically cured, biocompatible materials demonstrate satisfactory prophylactic characteristics.

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Journal articles on the topic 'Interfacial tissues'

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