医用硅橡胶亲水改性研究进展

硅橡胶材料在生物医学领域有着广泛的应用,但其结构组成决定了材料本身具有弱极性和疏水性,导致其与机体相容性差,因而需要提升硅橡胶的亲水性能.从表面和本体改性两大方面综述了提升医用硅橡胶亲水性能的改性方法,分析比较各种改性方式的优缺点,并对未来医用硅橡胶的发展方向进行了展望.     

SMA基PVDF微孔膜生物相容性研究

以超临界CO2(SCCO2)为分散介质,在聚偏氟乙烯(PVDF)微孔膜上进行马来酸酐和苯乙烯的接枝共聚,合成出超高相对分子质量(Mw=8.4×106)的苯乙烯/马来酸酐交替共聚物(SMA)基微孔PVDF膜。吸附实验表明,接枝率增大,接枝膜对蛋白吸附减少,抗污染性增强;细胞迁移实验中,接枝膜上细胞迁移范围及数量远高于原膜,生物相容性好;细胞粘附实验说明,接枝膜有助于细胞的粘附生长;细胞活性实验显示,细胞在接枝膜表面经3d培养后的乳酸脱氢酶活力低于4.5U/mL,说明接枝膜无细胞毒性;接枝膜动物急性实验中,未出现小白鼠死亡、瘫痪和呼吸困难等中毒现象。因此,接枝膜作为血液透析膜材料具有潜在应用前景。     

医用NiTi形状记忆合金表面改性

对NiTi形状记忆合金表面生物活性化处理及生物相容性的发展方向进行了综合评述。讨论了制备TiN保护层、TiO2氧化膜、HA涂层、多孔钛涂层的常用方法,对NiTi合金改性技术的发展方向进行了探讨,并指出在人体模拟溶液中的长期跟踪研究将是NiTi形状记忆合金的研究热点。     

表面Pd/Fe薄膜对316L不锈钢生物相容性的影响

采用表面有和无Pd/Fe薄膜的316L不锈钢样品进行溶血实验;提取样品浸提液进行细胞毒性实验,包括形态学观察、四唑盐(MTT)比色法测定和细胞相对增殖度(RGR)计算,以研究评价表面Pd/Fe薄膜对316L不锈钢生物相容性的影响.结果表明:与未镀膜的316L不锈钢相比,表面镀Pd/Fe的316L不锈钢的溶血率显著下降,而表面细胞数量和RGR显著增大,即表面Pd/Fe薄膜可显著提高316L不锈钢的生物相容性.     

Characterization of surface oxide films and cell toxicity evaluations with a quenched titanium surface

This study characterizes the surface of the oxide film that forms on titanium metal through the use of thermal and quenching treatments in cold water and investigates the effects of the surface characteristics and cellular interactions of a modified titanium surface. A range of sample groups were prepared in heat treatments of pure titanium at 600°C, 700°C, 800°C, 900°C, and 1000°C and subsequent quenching in cold water. The surface topography, roughness, crystallite size and crystal intensity were found to depend on the heating temperature. An increased surface roughness was observed with increases in the heating temperature and the quenching. The surface roughness was in the range of 0.15 μm–1.07 μm. In vitro cell responses were evaluated with mouse osteoblast MC3T3 cells in terms of cell proliferation and differentiation. MTT assays showed an increase in the living cell density and proliferation upon heating and quenching the titanium surface. The results of this study indicate that the cell toxicity was sensitive to the surface roughness and that it decreased as the roughness of the Ti increased.     

Comparative Study of Silver Nanoparticles Coated and Uncoated NiO–Fe2O3–CaO–SiO2–P2O5 Ferromagnetic Bioactive Ceramics

Bioactive ferromagnetic ceramics of system xNiO–(3?x)Fe₂O₃–52CaO–30SiO₂–15P₂O₅, (x = 0, 3 mol%) have been prepared in the laboratory using sol–gel technique. Silver nanoparticles coating has been undertaken on the surface of synthesized samples. Comparative study of silver nanoparticles coated and uncoated samples has been undertaken with the help of transmission electron microscopy, X‐ray diffraction (XRD), degradation, drug delivery, hemolysis, antimicrobial, and cell culture studies. XRD patterns indicate the growth of hydroxyl apatite layer on the surface of coated as well as uncoated samples. Ferromagnetic properties of samples have been investigated with the help of vibrating sample magnetometer technique. Samples have shown good response as drug carriers under normal conditions as well as under the influence of magnetic field. Drug release mechanism and mesoporus nature of samples have been investigated with the help of Brunauer–Emmett–Teller technique. Nonreactivity of samples (coated and uncoated) with red blood cells and white blood cells show nontoxic nature of the samples. Coated samples have shown better antimicrobial properties against six different microorganisms, including some resistive strain like methicillin‐resistant Staphylococcus aureus with minimum inhibitory concentration of 0.05 mg/ml as compared to uncoated samples. It has been observed that samples also provide a healthy environment for the growth of MG 63 cell lines. It has been noticed that presence of silver nanoparticles on the surface of samples improve degradation and antimicrobial properties.     

Effects of PMMA and Cross-Linked Dextran Filler for Soft Tissue Augmentation in Rats

This study was conducted for evaluation of the ability to maintain efficacy and biocompatibility of cross-linked dextran in hydroxypropyl methylcellulose (DiHM) and cross-linked dextran mixed with PMMA in hydroxypropyl methylcellulose (PDiHM), compared with hyaluronic acid (HA) filler. Saline and HA solution was administered in the negative and positive control groups, and DiHM and PDiHM were administered in the test groups (n = 10 in each group). The site of cranial subcutaneous injection was the mid-point of the interpupillary line, and the site of intraoral submucosal injection was the ridge crest 2 mm below the cervical line of the mandibular left incisor. Before and immediately after filler injection, intraoral photos and lateral cephalometric radiographs were taken for analysis and comparison of the effect of the filler on the injection sites. The filler injected areas were converted into sequential size changes (%) of the baseline. Histomorphologic examination was performed after 12 weeks. The smallest value in the filler injected area was observed during the experimental period in the normal saline group (p < 0.001), which was almost absorbed at 4 weeks (7.19% ± 12.72%). The HA group exhibited a steady decrease in sequential size and showed a lower value than the DiHM and PDiHM groups (saline < HA < DHiM, PDHiM, p < 0.001). DiHM and PDiHM tended to increase for the first 4 weeks and later decreased until 12 weeks. In this study on DiHM and PDiHM, there was no histological abnormality in cranial skin and oral mucosa. DiHM and PDiHM filler materials with injection system provide an excellent alternative surgical method for use in oral and craniofacial fields.     

胶原蛋白-葡甘聚糖-软骨素(CKCs)共混膜的生物相容性研究

通过内皮细胞-膜复合物的培养、组织学观察和MTT法对细胞增殖的测定以及动态凝血试验、溶血试验和复钙试验,考察了胶原蛋白-葡甘聚糖-软骨素(CKCs)共混膜的细胞相容性和血液相容性,为共混膜在生物医学领域的应用提供理论依据。