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Biomedical Engineering Trends in Materials Science Part 17

Tham khảo tài liệu 'biomedical engineering trends in materials science part 17', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 472 Biomedical Engineering Trends in Materials Science interest and activity in the application of synthetic polymers in medicine particularly for surgical and dental implants. The most critical property of a polymeric material is that it has acceptable tissue compatibility. If this criterion is not met local tissue irritation may result. In general the chemical structure electric charge hydrophilicity and hydrophobilicity surface roughness micro-heterogeneity and flexibility of the materials affect the performance of cells and tissues on the materials Minoura 1993 Yang Tsai 2010 . Biocompatibility can be characterised by a whole series of negatives for example that the material was non-toxic non-irritant non-thrombogenic non-carcinogenic and so on. Such a state of compatibility was most likely to be achieved by a material being inert and unrecognisable by the tissue. A desirable property of a synthetic polymeric material used in biomedical applications is that it has acceptable tissue compatibility. If this criterion is not met local tissue irritation may result. One particular method used to obtain these desired properties is grafting hydrophilic compounds namely a hydrogel onto hydrophobic backbones. Hydrogels have physical properties similar to those of human tissue and possess excellent tissue compatibility and are used as biomedical materials. The main disadvantages of hydrogels are their poor mechanical properties after swelling. To overcome this problem Yang Hsiue 1996 grafted hydroxyethyl methacrylate HEMA onto SBS via UV radiation. The mechanical properties of SBS-g-HEMA were found to be superior to those of poly HEMA and were identical to those of SBS. From their measurements the contact angle and blood clotting time the wetting and non-thrombogenic properties of SBS-g-HEMA were better than those of SBS. Yang et al. 1997 have also researched into the graft copolymerisation of dimethyl amino ethyl methacrylate DMAEMA with SBS and it was found that the .