葡甘聚糖一胶原蛋白一壳聚糖共混膜（I）

用溶液共混法制备了葡甘聚糖一胶原蛋白一壳聚糖（KCCS）共混膜。并用FT—IR，X—RD，SEM及透光率表征了膜的结构，同时测试了膜的抗张强度、断裂伸长率、吸水率、透水汽性、渗透性和吸附性。结果表明：共混膜中葡甘聚糖、胶原蛋白及壳聚糖之间存在着强烈的相互作用和良好的相容性，三者共混明显改善了纯聚合物和二元膜的性能。以共混膜为载体培养内皮细胞，发现共混膜具有良好的细胞相容性，预示着共混膜可作为潜在的组织工程支架材料。     

壳聚糖／魔芋葡甘聚糖共混膜细胞毒性和机械性能研究

目的利用天然高分子材料壳聚糖（CS）和魔芋葡甘聚糖（KGM）制备两者含量不同比例的生物膜,测定其细胞毒性和机械性能。方法流延法制备CS与KGM含量不同比例的混合膜。并将其与人脐带间充质干细胞联合培养,观察其细胞毒性：测定其断裂伸长率、拉伸强度及吸水率。结果CS/KGM含量比例分别为3：0、2：1、1：1和1：2制备的8种共混膜,具有良好的细胞毒性：膜平均厚度0．110mm,拉伸强度为35．84～48．17MPa,断裂伸长率为4．84％-6．25％,吸水率均随着CS含量增加而增加。结论CS／KGM含量比为3：0、2：1、1：1和1：2制备的共混膜,都具有良好的细胞毒性,初步具备了引导组织再生膜的基本性能。     

魔芋葡甘聚糖/透明质酸共混膜的体外细胞生物相容性

背景：高分子材料透明质酸与魔芋葡甘聚糖均可用于防治术后粘连。 目的：观察兔骨髓间充质干细胞与魔芋葡甘聚糖-透明质酸共混膜复合培养的生物相容性。 方法：取第3代兔骨髓间充质干细胞与魔芋葡甘聚糖-透明质酸共混膜体外复合培养,倒置显微镜和扫描电镜观察复合程度,MTT法检测细胞增殖。体外定向外诱导魔芋葡甘聚糖-透明质酸共混膜上的骨髓间充质干细胞向脂肪细胞分化,油红O染色检测其分化效果。 结果与结论：骨髓间充质干细胞与魔芋葡甘聚糖-透明质酸共混膜修复材料复合良好,倒置显微镜和扫面电镜观察均可见细胞在共混膜上良好黏附与增殖;体外定向诱导魔芋葡甘聚糖-透明质酸共混膜上的骨髓间充质干细胞可向脂肪细胞分化,具有成脂潜能。说明魔芋葡甘聚糖-透明质酸共混膜与骨髓间充质干细胞具有良好的生物相容性。     

壳聚糖-透明质酸共混膜对兔角膜基质细胞生长的影响

观察各种壳聚糖-透明质酸共混膜对角膜基质细胞生长的影响作用,研究透明质酸混入比例对共混膜与细胞相容性的影响.以共混膜为载体培养兔角膜基质细胞,通过光学和电子显微镜,观察细胞在膜上的生长情况;通过MTT法,检测细胞在共混膜上的贴附率和生长活性;通过检测培养基中乳酸脱氢酶的活性,预示壳聚糖-透明质酸共混膜与角膜基质细胞的相容性.以低于1:0.1的比例混入透明质酸.可以提高细胞在共混膜上的贴附率、生长速度,细胞在共混膜上的生长状态好于在壳聚糖膜上的生长状态.结果提示,以低于1:0.1的比例混入透明质酸,可以提高壳聚糖膜与角膜基质细胞的相容性,促进细胞生长;而以高于1:0.1的比例混入透明质酸,则不利于细胞在共混膜上的生长,降低了壳聚糖膜与角膜基质细胞的相容性.     

胶原-葡甘聚糖-硫酸软骨素复合膜对全层皮肤损伤修复的实验研究

用小猪皮提取胶原,与葡甘聚糖和硫酸软骨素复合改性制成复合膜,研究用于修复全层皮肤缺损。选用新西兰大白兔14只,1.5~2.0kg,在胸腰脊柱两侧切割建立2cm×4cm全层皮肤缺损模型,左侧为试验组,敷以复合膜,右侧不经任何处理,作为空白对照组。观察创面的变化,定期取材,作组织学检查。复合膜有防止创口出血和感染的作用,实验组创伤愈合形成矩性痂,空白对照组形成线性痂。无明显的免疫排斥反应,有促进皮肤结构再生的能力。胶原-葡甘聚糖-硫酸软骨素复合膜对创伤的修复有促进作用。     

硫酸酯化葡甘聚糖凝胶颗粒的微观形貌及其吸附行为研究

制备了硫酸酯化魔芋葡甘聚糖凝胶颗粒血液低密度脂蛋白吸附剂，扫描电镜观察产物呈交联网状多孔结构。体外静态吸附实验表明：在37℃振荡吸附2h后，对总胆固醇（TC）、低密度脂蛋白及超低密度脂蛋白胆固醇（LDL＋VLDL-C）、高密度脂蛋白胆固醇（HDL-C）的吸附率分别为52．68％、54．76％、27．78％。通过吸附动力学曲线和吸附等温线分析，吸附剂对LDL＋VLDL-C的作用包括类似分子筛的吸附和电荷间静电相互作用两种方式。     

壳聚糖与硫酸软骨素共混膜性质的研究

以壳聚糖和硫酸软骨素按一定比例制备出共混膜，研究了膜片的透光性、含水量、渗透性、力学性质、表面结构、生物降解性、生物相容性等性质。结果表明该共混膜具有较好的透光性、通透性、生物降解性和生物相容性，膜表面较粗糙。以此共混膜为载体培养兔角膜基质细胞，发现细胞在此共混膜上生长良好。制备膜片随着加入CaSO4量的增加，膜的通透性也随之增加。     

壳聚糖相对分子量对壳聚糖膜与角膜基质细胞相容性的影响

以脱乙酰度为95％，相对分子量分别为130KDa、220KDa、300KDa和500KDa的壳聚糖制备不同的壳聚糖膜。以各种壳聚糖膜作为基质，体外培养兔角膜基质细胞，通过观察角膜基质细胞在不同壳聚糖膜上的生长状态、贴附情况、生长曲线以及乳酸脱氢酶的活性，研究壳聚糖相对分子量对壳聚糖膜与角膜基质细胞生物相容性的影响。实验结果表明壳聚糖相对分子量对壳聚糖膜与角膜基质细胞的相容性具有重要的影响，相对分子量过高或过低的情况下，壳聚糖膜与角膜基质细胞相容性较差，对细胞损伤程度较大，细胞在膜上的贴附、生长能力较差；以相对分子量在200KDa～300KDa之间的壳聚糖制备出的膜与角膜细胞具有较好的相容性，细胞可在膜上长成密集单层，适合作为角膜培养的支架材料。     

胶原蛋白/壳聚糖复合纳米纤维膜在生物医学工程中的应用

背景：胶原蛋白-壳聚糖复合纳米纤维膜以其优异的力学性能和良好的组织细胞相容性而成为近年来科学研究的热点。 目的：总结胶原蛋白/壳聚糖复合纳米纤维膜在生物医学工程中的应用进展。 方法：以“胶原蛋白、壳聚糖、复合纳米纤维膜、胶原蛋白/壳聚糖复合纳米纤维膜、collagen/chitosan、compound Nanofiber membrane、collagen/chitosan compound nanofiber membrane、development of research” 为检索词,应用计算机检索Pubmed数据库、Elsevier数据库、万方数据库1993-01/2010-05关于胶原蛋白/壳聚糖复合纳米纤维膜研究的相关文章,对53篇文献进行分析。 结果与结论：研究表明,将胶原蛋白/壳聚糖共混,在不同条件下交联,其共混复合物在力学性能方面较单一的胶原蛋白有一定的改善,其共混膜可以作为较小软骨缺损的修复的支架材料。研究证实胶原蛋白/壳聚糖复合纳米纤维膜有着优异的力学性能、很好的组织细胞相容性和生物可降解性。文章从胶原蛋白和壳聚糖单一生物材料的缺陷性、复合纤维膜的优势及其在生物医药工程中的应用方面进行了探讨。     

胶原蛋白-壳聚糖复合纳米纤维膜用于皮肤缺损的修复

背景：体外实验证实：胶原蛋白-壳聚糖(80∶20)复合纳米纤维膜具有优异的生物力学性能、生物相容性和生物可降解性。但目前缺乏此材料在体内方面的研究。 目的：观察胶原蛋白-壳聚糖复合纳米纤维膜修复SD大鼠背部全层皮肤缺损创面的作用。 方法：30只SD大鼠制备背部全层皮肤缺损创面后随机抽签法分为2组,实验组用胶原蛋白-壳聚糖(80∶20)复合纳米纤维膜覆盖后,用油纱及干纱布包扎并创缘外缝线打包固定;对照组仅用油纱及干纱布包扎并创缘外打包固定。 结果与结论：修复后14 d实验组创面已基本对合,干痂;苏木精-伊红染色显示创面毛细血管数量减少,纤维含量增多。对照组创面对合不整齐,创面较实验组大;苏木精-伊红染色显示毛细血管数量较多,扩张明显,大量炎性细胞浸润。提示胶原蛋白-壳聚糖复合纳米纤维膜较普通纱布敷料能更好的促进创伤修复、愈合。     

Influence of Stereochemistry on Relative Reactivities of Glucosyl and Mannosyl Residues in Konjac Glucomannan (KGM)

Methylation in water with NaOH/MeI is applied to study the influence of the stereochemistry on relative reactivities of d ‐mannosyl (M) compared to d ‐glucosyl (G) units in konjac glucomannan (KGM). The pH is kept constant at 13.6 over the course of the reaction and aliquots are removed after various time intervals. Methyl distribution in G and M residues is determined after perethylation, hydrolysis, and conversion to O‐ethyl‐O‐methyl‐alditol acetates. The order of relative rate constants determined for the O‐methyl Konjac glucomannans (M‐KGMs) in degree of substitution (DS) range 0.3–0.8 is G‐k ₆ > M‐k ₆ > G‐k ₂ ≈ M‐k ₂ > M‐k ₃ > G‐k ₃. Oligosaccharides obtained by partial hydrolysis after full protection of M‐KGM with MeI‐d ₃ are labeled with m‐amino‐benzoic acid and measured by liquid chromatography–electrospray ionization–mass spectrometry. DS/DP profiles are in full agreement with random distribution of methyl groups. Thermal properties of M‐KGMs are analyzed by differential scanning calorimetry and thermogravimetric analysis. Decomposition temperature increases with DS, while the temperature of an endothermic change decreases.

     

聚丙交酯(PL)/丙交酯-聚乙二醇共聚物(PLEG)共混微球的制备、表征及释药行为

ＰＬ与ＰＬＥＧ是生物降解、生物相容的高分子材料,利用它们作为药物控释载体已引起人们广泛的重视。我们合成了含不同ＰＥＧ链段长度的ＰＬＥＧ共聚物,并利用ＰＬ与ＰＬＥＧ这两种材料各自的优点制备载有人绒毛促性腺激素（ｈＣＧ）的共混微球以提高ｈＣＧ在微球中的包埋率,结果表明采用Ｐ（Ｌ－ｃｏ－ＰＥＧ６０００）（９０：１０）与ＰＬ共混制备得到的微球中,ｈＣＧ的包埋率高于单独用ＰＬ或ＰＬＥＧ制得的微球。ｈＣＧ的体     

Structural Characteristics and Properties of Silk Fibroin/Poly(lactic acid) Blend Films

This paper describes the preparation and characterization of blend films composed of regenerated silk fibroin (SF) and poly(lactic acid) (PLA). FT-IR and XRD of the SF/PLA blend films with different ratios indicated that the secondary structural transition of SF from Silk I to Silk II was induced upon blending with PLA. The effects of SF/PLA blend ratios on the mechanical and physical properties of the blend films were investigated. Compared to pure SF film, the mechanical and thermal properties of the blend films were improved, and surface hydrophilicity and swelling capacity decreased due to the secondary structural transition of SF to Silk II. Among the blend films with different ratios, the SF/PLA blend film with 7 wt% PLA content showed excellent mechanical properties. Meanwhile, the BSA adsorption amount on the blend film increased with the increase of PLA content. In vitro cell adhesion test showed that the blend film was a good matrix for the growth of L929 mouse fibroblast cells. Consequently, controlling the PLA content in the SF film can improve the mechanical and physical properties of the SF film and provide a promising opportunity to widen potential application of SF in the biomaterials field.     

Collagen Protein Abnormalities Produced by Site-Directed Mutagenesis of the Proal(I) Gene

Site-directed mutagenesis of collagen genes offers a powerful new approach for studying structure-function relationships. The construction of engineered mutant collagen genes coding for glycine substitutions and their expression giving rise to the osteogenesis imperfecta type II phenotype in cells and transgenic mice has recently been achieved^I. This paper further defines the molecular abnormalities of collagen and bone pathology resulting from the expression of the mutant genes.     

Human osteosarcoma cell adhesion behaviour on hydroxyapatite integrated chitosan-poly(acrylic acid) polyelectrolyte complex

A novel degradable composite system has been prepared by integrating hydroxyapatite, Ca₁₀(PO₄)₆(OH)₂, (HAP) in a polyelectrolyte complex matrix of chitosan (CHI) and poly(acrylic acid) (PAA). The composite was formulated by integrating 80 wt.% HAP in the polyelectrolyte complex matrix of CHI and PAA in the ratio 40/60 (designated as CPH). The composite could be easily fabricated into clinically significant shapes by a simple moulding procedure intended for bone graft applications. The adhesion behaviour of human osteosarcoma (HOS) cells on this degradable composite system was studied by selecting the polyelectrolyte complex, CHI/PAA 40/60 (designated as CP) as control sample. Light microscopic observations show that cells around CPH retained the typical morphology of HOS cells while cells around the polyelectrolyte complex showed a cytotoxic effect. The adhesion behaviour as well as morphological responses of the seeded cells was further investigated by scanning electron microscopy. The scanning electron micrographs of the polyelectrolyte complex, CP, showed the presence of rounded cells with raised nuclear regions, indicating delayed spreading; cells adhered on CPH were flattened with filopodia and showed good attachment and spreading, indicating better adhesion onto the HAP integrated composite. Comparing the MTT assay for quantitative evaluation of cell viability, CPH showed a higher percentage of metabolically active cells compared to CP.     

羟基磷灰石/胶原-聚乳酸三维多孔框架材料的制备成形及分析

目的：合成新型的复合生物材料框架作为骨组织工程研究的细胞外基质材料。方法：本研究采用材料学自组装技术的原理，以Ⅰ型胶原蛋白为分子模板，引导钙磷盐在液相中的矿化，制备具有天然骨基质层状结构的羟基磷灰石／胶原复合材料，并以热致分相法制备了羟基磷灰石／胶原-聚乳酸复合三维多孔框架。结果：羟基磷灰石／胶原复合材料具有与天然骨基质相似的成分与结构，加入聚乳酸制备成三维多孔框架，孔隙直径界于50um-300um。结论：羟基磷灰石／胶原-聚乳酸复合三维多孔框架可能作为骨组织工程良好的细胞外基质材料。     

Porcine bone marrow stromal cell differentiation on heparin-adsorbed poly(e-caprolactone)–tricalcium phosphate–collagen scaffolds

We evaluate the potential of heparin as a substrate component for the fabrication of bone tissue engineering constructs using poly(e-caprolactone)–tricalcium phosphate–collagen type I (PCL–TCP–Col) three-dimensional (3-D) scaffolds. First we explored the ability of porcine bone marrow precursor cells (MPCs) to differentiate down both the adipogenic and osteogenic pathways within 2-D culture systems, with positive results confirmed by Oil-Red-O and Alizarin Red staining, respectively. Secondly, we examined the influence of heparin on the interaction and behaviour of MPCs when seeded onto PCL–TCP–Col 3-D scaffolds, followed by their induction into the osteogenic lineage. Our 3-D findings suggest that cell metabolism and proliferation increased between days 1 and 14, with deposition of extracellular matrix also observed up to 28 days. However, no noticeable difference could be detected in the extent of osteogenesis for PCL–TCP–Col scaffolds groups with the addition of heparin compared to identical control scaffolds without the addition of heparin.     

姜黄素/聚乳酸—乙醇酸共聚物复合薄膜的制备及抗凝血研究

血管支架内再狭窄是血管支架临床应用中最突出的问题,药物洗脱支架的问世成为冠心病介入治疗的一个重要里程碑。但是目前的药物洗脱支架还存在抗凝血不足的问题,药物洗脱支架植入晚期血栓形成的病例在临床上有所报道。姜黄素具有抗增生以及抗凝血等多种药理活性,有望成为药物洗脱支架的新颖药物。我们以可降解高分子材料聚乳酸-乙醇酸共聚物(PLGA)为载体分别制备了三种浓度(3wt%、5wt%、8wt%)的姜黄素复合薄膜。采用傅立叶变换红外光谱研究了复合薄膜的组成成分,结果显示:姜黄素与PLGA的特征峰在复合薄膜的红外图谱中均有出现;体外血小板黏附实验结果显示姜黄素复合薄膜表面的血小板黏附数量减少,较少团聚、变形和激活;复合薄膜的部分凝血活酶时间(APTT)长于纯PLGA薄膜的APTT,这都表明姜黄素/聚乳酸-乙醇酸共聚物复合薄膜的抗凝血性能得到改善,且复合薄膜的抗凝血性能在实验药物浓度范围内随着药物含量的增加,材料的抗凝血性能进一步提高。