ABSTRACT
Currently three dimensional bio-printing technology has become one of the hot topics for tissue engineering tracheal grafting.Different biomaterials have their own performance advantages in the preparation and regeneration of tracheal scaffolds.It is particularly imperative to seek natural or polymeric materials with excellent profiles of printability, structural stability and biocompatibility to enable neo-cartilage formation, neo-epithelialization and neo-vascularization of tissue engineering trachea grafting.This review summarized the shortcomings and challenges of classifying and applying materials for three dimensional bio-printing tissue engineering trachea, aiming to provide new rationales for researches and applications of tissue engineering tracheal grafting.
ABSTRACT
In this study, cytometric beads array(CBA) was used to determine the immunoglobulin content in humoral immunity evaluation of biomedical materials. The bovine-derived acellular dermal matrix was selected as a test sample and implanted into Balb/C mice subcutaneously to 4 weeks according to the high, medium and low dose groups. Four weeks later, IgG1, IgG2a, IgG2b, IgG3, IgA, and IgM were measured by CBA. The data of the test group and the control group were analyzed statistically. The results showed that compared with the negative control group, there was no significant difference in the IgG3, IgA content in the positive control group, while the IgG1, IgG2a, IgG2b, and IgM contents were significantly higher than the negative control group; no significant differences were seen in the sample groups. The results show that the method is suitable for analysis of immunoglobulin content in humoral immunity evaluation of biomedical materials.
Subject(s)
Animals , Cattle , Mice , Immunity, Humoral , Immunoglobulin A , Immunoglobulin G , Immunoglobulin M , Mice, Inbred BALB C , Mice, Inbred CBAABSTRACT
BACKGROUND: Polyisobutylene and block copolymer and its crosslinked product are a kind of novel thermoplastic elastomer. They have unique properties and excellent biocompatibility, which is a promising medical biomaterial and applied extensively. OBJECTIVE: To review the research progress and applications of polyisobutylene and its thermoplastic elastomers, and to discuss the application prospect of polyisobutylene-based polymers as medical implant materials. METHODS: A computer-based retrieval of PubMed, Web of Science, CNKI and WanFang databases was conducted for the articles about polyisobutylene published from 1958 to 2019. The key words were “polyisobutylene and block copolymer, polyisobutylene and thermoplastic elastomer, polyisobutylene and biomaterials, polyisobutylene and modification, polyisobutylene and medical application” in English and Chinese, respectively. In accordance with the inclusion and exclusion criteria, 65 eligible articles were included for review. RESULTS AND CONCLUSION: Polyisobutylene and block copolymer and its crosslinked products have favorable biocompatibility and stability. By making full use of polyisobutylene-based materials’ advantages, with the combination of other biomaterials and usage of new technology for surface modification, the copolymer will be more competitive in the field of medical implant in the future, including eye implant materials, soft biomaterials and drug delivery systems.
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Objective To investigate the biomechanical behavior of porous scaffold with different materials (Ti, Ta, PEEK, HA) for repairing rabbit femur defects under immediate loading by three-dimensional finite element analysis (FEA), so as to explore the best porous scaffold material from the perspective of biomechanics. Methods The CBCT combined with software such as Mimics, SolidWorks, Geomagic Studio, ANSYS were used to establish an immediate loading model for the repair of rabbit femur defects with porous scaffolds at different stages of bone healing. The stress and strain distributions on the scaffolds and the surrounding tissues were calculated. Results The maximum equivalent stress of porous scaffold decreased along with the bone healing. In the granulation tissue and fibrous tissue model, the ratio of the maximum equivalent stress to the yield strength of porous scaffold was: HA＞Ta＞PEEK＞Ti. The maximum equivalent stress of the HA porous scaffold was greater than its yield strength. The number of suitable strain elements in tissues around the porous scaffolds was: PEEK＞Ta＞Ti＞HA. The number of potential fracture strain elements in tissues around the porous scaffolds was: HA＞Ta＞PEEK＞Ti. Conclusions The HA porous scaffold could not bear the immediate load and guide bone healing well under immediate loading. The elastic modulus of PEEK porous scaffold was similar to that of bone tissues, which could preferably guide bone healing. PEEK was an ideal porous scaffold material under immediate loading. The research findings provide
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Three kinds of biomedical materials of stomatology were introduced,including metal materials,polymers and non-metal bio composites.The literatures related to stomatology biomedical materials from 2008 to 2015 were collected in PubMed medical literature retrieval service system,and then statistical method was used to analyze the literature number,the numbers of literatures on different materials as well as the nations distribution.Composite,intelligent and functional materials were pointed out to be taking the place of metal materials,and thus might extend their clinical application in the future.
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Los modelos y simulaciones de los efectos biomecánicos presentes en la arteria aorta, le proporcionan al especialista de la salud una herramienta computacional, que puede ser empleada en la prevención y el tratamiento de las enfermedades cardiovasculares. Es por esto que en la presente investigación se desarrolla un modelo matemático con la finalidad de implementarlo en simulaciones tridimensionales digitales que permitan analizar el comportamiento mecánico de arterias. Primero se describe la metodología utilizada en la construcción de la geometría de la arteria basada en imágenes provenientes de una tomografía axial computarizada, los ensayos experimentales necesarios para la obtención de los parámetros mecánicos requeridos por el modelo y por último su orden fraccional. Con lo que se obtiene una simulación mediante elementos finitos donde se identifican las zonas de mayor concentración de esfuerzos y el campo de desplazamientos. Para poder obtener estos resultados se empleó una formulación novedosa basada en modelos viscoelásticos de orden fraccional donde además se obtuvieron, a través del módulo complejo, los valores requeridos para la simulación.
The modeling and simulation of the biomechanical effects present in the aorta, give the health specialist a computational tool that can be used in the prevention and treatment of cardiovascular diseases. For that reason on this research a mathematical model was developed in order to implement digital dimensional simulations to analyze the mechanical behavior of arteries. First, its described the methodology used in the construction of the geometry of the artery based on images from a CT scan, next the necessary experimental tests to obtain mechanical parameters required by the model and finally his fractional order. Obtaining a finite element simulation where the areas of greatest stress concentration and the displacement field are identified. To obtain these results a novel formulation based on fractional order viscoelastic models was used and the values required for simulation were obtained through the complex modulus.