三种角膜内皮细胞载体膜片的性质研究

以壳聚糖分别与硫酸软骨素、羧甲基壳聚糖、透明质酸按一定比例制备出共混膜，研究了膜片的透光性、吸水率、渗透性、力学性质、表面结构、红外图谱等物理性质。以共混膜为载体培养兔角膜内皮细胞，从而筛选出了透明度高，亲水性好，机械性能优异，最适合内皮细胞贴附生长的壳聚糖．硫酸软骨素共混膜片，并对其生物降解性、生物相容性等性质进行了研究。为了提高壳聚糖．硫酸软骨素共混膜片的通透性，在膜片制备过程中加入不同剂量的醋酸盐作为扩孔剂，结果表明当加入一定量的醋酸盐为扩孔剂时，膜片的通透性提高。     

兔角膜内皮细胞载体的体外培养及移植的研究

以特定曲率的壳聚糖-硫酸软骨素共混膜为载体，构建兔角膜内皮。研究了共混膜的透光性、体外酶降解性以及兔角膜内皮细胞在载体上的细胞贴附性、细胞形态及膜强度等性质。结果表明，共混膜的透光率达90％以上，生物降解性良好。该共混膜有良好的细胞贴附性及机械强度；兔角膜内皮细胞可在共混膜上长成良好的单层，细胞形态较好，并贴附牢固，振荡后细胞无脱落，膜片保持完整。将培养好的载体植入到去除内皮层的兔角膜中，术眼在56天内基本保持透明，说明体外构建的内皮可执行角膜内皮层的部分功能。     

不同分子量壳聚糖膜性质的研究

分别以分子量为130，000、220，000、300，000、550，000道尔顿的壳聚糖制备壳聚糖膜，并研究了各膜的表面结构、结晶性、力学特性、渗透性、透光透气性、吸附性、生物降解性等。结晶表明壳聚糖膜的各种特性和壳聚糖的分子量相关，高分子量的壳聚糖膜表面较为光滑，透光性较好，透气性、渗透性和生物降解性较差；低分子量的壳聚糖膜表面较为粗糙，透气性、渗透性和生物降解性较好，但透光性较差。经分析认为膜的结晶性和超微结构决定了不同分子量壳聚糖膜具有不同的性质。     

N-乙酰化壳聚糖膜的制备和性质研究

以乙酸和甲醇为介质，利用壳聚糖和乙酸酐制备出N-乙酰化壳聚糖膜。对膜的亲水性、吸水性、结晶性、透光性、渗透性以及对血清蛋白的吸附性和与兔角膜上皮细胞的生物相容性进行了研究。结果表明N-乙酰化壳聚糖膜有一定的亲水性、吸水性、结晶性，有很好的透光性和渗透性，对血清蛋白有一定的吸附能力，以该膜为载体培养兔角膜上皮细胞实验结果表明膜与兔角膜上皮细胞具有很好的生物相容性。     

生物降解性防术后粘连膜的实验研究

本文首次采用新型医用天然高分子材料壳聚糖作膜材料，制备了可降解吸收防术后粘连膜，并通过动物实验研究其生物降解性和生物相容性．初步研究结果表明，壳聚糖具有很好的成膜性。壳聚糖膜在小鼠体内可以缓慢降解，并具有较好的生物相容性，是一种很有发展前景的天然防术后粘连膜材料。     

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。     

生物降解性防术后粘加膜的实验研究

本文首先采用新型医用天然高分子材料壳聚糖作膜材料，制备了可降解吸收的防术后粘连膜，并通过动物实验研究其生物降解性和生物相容性。初步研究结果表明，壳聚糖具有很好的成膜性。壳莫大 半导体环境可以缓慢降解，并具有较好的生物相容性，是一种很有发展前景的天然防术后宫膜材料。     

葡甘聚糖-胶原蛋白-壳聚糖共混膜(I)

用溶液共混法制备了葡甘聚糖-胶原蛋白-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—明胶混合膜的制备及其生物降解性研究

将壳聚糖与明胶按一定比例混合制膜，通过体外降解及动物体内实验研究了其降解性和生物相容性，结果表明壳聚糖－明胶混合膜在小鼠体现人降解速度较快，并具有较好的生物相容性，溶菌酶对混合膜的生物降解有促进作用。     

复合表面活性剂处理生物源性骨组织作为骨移植材料的生物安全性研究

目的 应用新型的表面活性剂处理生物源性骨组织,对其进行脱细胞效果及生物安全性评价,以期得到一种更安全、可靠的骨植入材料。方法2种阴离子表面活性剂ABS（十二烷基苯磺酸钠）和AES（脂肪醇聚氧乙烯醚硫酸钠）以及蒸馏水以重量比13：7：80的比例配制复合表面活性剂。以新鲜的牛松质骨为原料,复合表面活性剂脱脂脱细胞的两步法工艺,制备新型生物源性骨植入材料。对其进行组织学和表面超微结构观察,同时对表面活性剂处理的生物源性骨植入材料进行急性全身毒性试验、溶血试验、细胞毒性试验的生物安全性评价。通过骨长期植入试验观察表面活性剂生物源性骨的生物相容性和生物降解性。采用吸光度测量法界定骨材料中表面活性剂的残留量。结果复合表面活性剂生物源性骨颜色呈乳白色,无肉眼可见杂质,组织学及超微结构观察可见骨陷窝内细胞结构消失,骨小管空虚,胶原纤维排列整齐。生物安全性实验表明：按GB／T16886．11—1997急性全身毒性试验合格,溶血试验〈5％,细胞毒性试验0级。复合表面活性剂生物源性骨组织中表面活性剂的残留量低于0．1g／L。骨长期植入实验表明：4周时可见骨组织周围纤维组织生成,骨小梁内有细胞爬入,植入材料与宿主骨融合良好。8周时植入材料部分被机体吸收,24周后被机体完全吸收。结论复合表面活性剂处理的生物源性骨移植材料具有良好的生物相容性和生物降解性,是一种安全、可靠的骨植入材料。     

纤维素-大豆蛋白混合膜与内皮细胞生物相容性的实验研究

目的:研究和评价纤维素-大豆蛋白混合膜与内皮细胞的生物相容性,为其作为人工生物支架材料应用于组织工程提供实验依据。方法:将内皮细胞株ECV304与不同组分、碱处理前后的纤维素-大豆蛋白混合膜共培养,分别以四氮甲唑蓝(MTT)法检测细胞活力,以扫描电镜(SEM)观察细胞形态和生长状态。结果:与阴性对照组和单纯纤维素组相比,ECV304在纤维素-大豆蛋白混合膜上生长良好,大豆蛋白加入到纤维素膜中显著提高了ECV304的细胞活力;在碱处理后的混合膜表面,细胞长出许多足突伸入膜孔隙,明显促进细胞在膜表面粘附。结论:初步表明纤维素-大豆蛋白混合膜与内皮细胞ECV304生物相容性良好,在血管组织工程领域具有应用潜能。     

Novel Polymer Blends for the Preparation of Membranes for Biohybrid Liver Systems

It was found previously that membranes based on co-polymers of acrylonitrile (AN) and 2-acrylamido-2-methyl-propansulfonic acid (AMPS) greatly stimulated the functionality and survival of primary hepatocytes. In those studies, however, the pure AN–AMPS co-polymer had poor membrane-forming properties, resulting in quite dense rubber-like membranes. Hence, membranes with required permeability and optimal biocompatibility were obtained by blending the AN–AMPS co-polymer with poly(acrylonitrile) homopolymer (PAN). The amount of PAN (P) and AN–AMPS (A) in the blend was varied from pure PAN (P/A-100/0) over P/A-75/25 and P/A-50/50 to pure AN–AMPS co-polymer (P/A-0/100). A gradual decrease of molecular cut-off of membranes with increase of AMPS concentration was found, which allows tailoring membrane permeability as necessary. C3A hepatoblastoma cells were applied as a widely accepted cellular model for assessment of hepatocyte behaviour by attachment, viability, growth and metabolic activity. It was found that the blend P/A-50/50, which possessed an optimal permeability for biohybrid liver systems, supported also the attachment, growth and function of C3A cells in terms of fibronectin synthesis and P-450 isoenzyme activity. Hence, blend membranes based on a one to one mixture of PAN and AN–AMPS combine sufficient permeability with the desired cellular compatibility for application in bioreactors for liver replacement.     

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。     

Antifouling blood purification membrane composed of cellulose acetate and phospholipid polymer

The ideal surface of an artificial blood purification membrane needs hemocompatibility and durability of high performance; it should not adsorb any proteins or cells but should still have high permeability in the desired range of solute size. To improve the anti-fouling property of cellulose acetate (CA) membranes, a CA membrane blended with poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)) (PMB30) was designed as a blood purification membrane. The polymer solutions for preparing the membrane were prepared using a solvent mixture composed of N, N-dimethylformamide, acetone, 2-propanol or water. The CA and CA/PMB30 blend membranes with an asymmetric and porous structure were prepared by a phase inversion process.The characteristics of the CA/PMB30 blend membrane, such as structural properties, mechanical properties, and solute permeability were examined with attention to changes in the preparation conditions of the membrane. The CA/PMB30 blend membrane had good water and solute permeability and a sharp molecular weight cut-off property. Moreover, the amount of proteins adsorbed on the CA/PMB30 blend membrane surface was less than that of the original CA membrane and a conventional polysulfone membrane. Adhesion and activation of platelets on the CA/PMB30 blend membrane were reduced compared with that on a CA membrane. In addition, the CA/PMB30 blend membrane showed good permselectivity and an antifouling property during a long time ultrafiltration experiment with protein solutions.     

Approaches to improving the biocompatibility of porous perfluoropolyethers for ophthalmic applications

Porous perfluoropolyether (PFPE) membranes for ophthalmic applications were prepared with a zwitterion monomer, 3-[[2-(methacryloxy) ethyl](N,N-dimethyl)ammonio]-propane-1-sulphonate, copolymerized in weight ratios of 0-10%. The polymer samples were assessed for a range of physical properties, including equilibrium water content, bovine serum albumin permeability, transparency, refractive index and the ability to support corneal epithelial cell and tissue attachment, growth and migration. In vitro assessment of the polymers using bovine corneal epithelial cells and tissue showed that a zwitterion incorporation level of between 0% and 6% in the PFPE membranes supported the migration of an intact sheet of epithelial tissue without compromising epithelial cell attachment and growth, with 4-6% being the optimal level for these properties. Binding patterns of the cell adhesion glycoprotein fibronectin were also found to reflect the cell and tissue response. Effective nutrient permeability, refractive index and optical transparency were also maintained by the porous PFPE polymers containing this concentration of zwitterionic monomer. The presence of amounts of zwitterion greater than 6% was inhibitory to both tissue migration and cell growth and was associated with increased optical haze. These results demonstrated that it is possible to achieve the potential for increased biocompatibility in zwitterion-containing PFPE polymers without compromising existing beneficial characteristics.     

Preparation of PVA/PEI ultra-fine fibers and their composite membrane with PLA by electrospinning

Ultra-fine fibers of poly(vinyl alcohol)/polyethylenimine (PVA/PEI) were prepared by electrospinning of their blend solutions in water. Effects of PVA/PEI mass ratio and the polymer concentration on the fiber morphology were discussed by analysis of scanning electron micrographs. Results showed that uniform ultra-fine fibers could be obtained from an 8% PVA/PEI solution with 75:25 mass ratio. It was supposed that the introduction of PVA could promote electrospinning of PEI by weakening the intermolecular interaction and increasing solution viscosity. A composite membrane of PVA/PEI with poly(D,L-lactide) (PLA) was produced by co-electrospinning simultaneously from the aqueous 8% PVA/PEI (75:25) solution and a 20% PLA solution in N,N-dimethylformamide in two separated syringes. Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy verified the existence of PVA/PEI and PLA in the fibrous membrane. We attempted to incorporate PEI with PLA as ultra-fine fibers to diminish the acidic inflammation caused by biodegradation of PLA. The fibrous composite membrane of PVA/PEI-PLA could provide better biocompatibility and would be used as drug-delivery carriers or tissue-engineering scaffolds.     

Preparation of PVA/PEI ultra-fine fibers and their composite membrane with PLA by electrospinning

Ultra-fine fibers of poly(vinyl alcohol)/polyethylenimine (PVA/PEI) were prepared by electrospinning of their blend solutions in water. Effects of PVA/PEI mass ratio and the polymer concentration on the fiber morphology were discussed by analysis of scanning electron micrographs. Results showed that uniform ultra-fine fibers could be obtained from an 8% PVA/PEI solution with 75:25 mass ratio. It was supposed that the introduction of PVA could promote electrospinning of PEI by weakening the intermolecular interaction and increasing solution viscosity. A composite membrane of PVA/PEI with poly(D,L-lactide) (PLA) was produced by co-electrospinning simultaneously from the aqueous 8% PVA/PEI (75:25) solution and a 20% PLA solution in N,N-dimethylformamide in two separated syringes. Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy verified the existence of PVA/PEI and PLA in the fibrous membrane. We attempted to incorporate PEI with PLA as ultra-fine fibers to diminish the acidic inflammation caused by biodegradation of PLA. The fibrous composite membrane of PVA/PEI-PLA could provide better biocompatibility and would be used as drug-delivery carriers or tissue-engineering scaffolds.     

A collagen-based scaffold for a tissue engineered human cornea: physical and physiological properties

Stabilized collagen-glycosaminoglycan scaffolds for tissue engineered human corneas were characterized. Hydrated matrices were constructed by blending type I collagen with chondroitin sulphates (CS), with glutaraldehyde crosslinking. A corneal keratocyte cell line was added to the scaffolds with or without corneal epithelial and endothelial cells. Constructs were grown with or without ascorbic acid. Wound-healing was evaluated in chemical-treated constructs. Native, noncrosslinked gels were soft with limited longevity. Crosslinking strengthened the matrix yet permitted cell growth. CS addition increased transparency. Keratocytes grown within the matrix had higher frequencies of K+ channel expression than keratocytes grown on plastic. Ascorbic acid increased uncrosslinked matrix degradation in the presence of keratocytes, while it enhanced keratocyte growth and endogenous collagen synthesis in crosslinked matrices. Wounded constructs showed recovery from exposure to chemical irritants. In conclusion, this study demonstrates that our engineered, stabilized matrix is well-suited to function as an in vitro corneal stroma.