【作者】 张金凤；

【导师】 熊党生；

【作者基本信息】 南京理工大学 ， 材料学， 2009， 硕士

【摘要】 关节软骨损伤是导致关节疼痛的一种普遍的损伤形式,是临床骨科常见的疾病,长期以来人们一直在寻找和研制理想的软骨修复材料。聚乙烯醇(PVA)水凝胶除了具备一般水凝胶的性能外,特别具有毒性低、机械性能优良、含水量高和生物相容性好等优点,是一种非常有前途的人工软骨修复材料。为了进一步提高PVA水凝胶作为软骨修复材料的性能,本文采用冷冻-解冻循坏和γ射线辐照交联相结合的方法制备了PVA/PVP(聚乙烯吡咯烷酮)复合水凝胶,用冷冻解冻法制备了PVA/PAAM(聚丙烯酰胺)复合水凝胶,并探讨了其作为关节软骨修复材料的可行性。采用扫描电镜,红外光谱等技术手段对复合水凝胶进行显微形貌观察和结构表征。系统研究了复合水凝胶的亲水性、力学性能和生物摩擦学性能及生物相容性。主要内容与结果如下:1.采用冷冻解冻和γ辐照相结合的方法制备的PVA/PVP复合水凝胶软骨修复材料具有类似于天然关节软骨的多孔结构。经γ辐照后,试样的表面韧性增强,内部网络结构得到强化,提高了试样的耐磨性;2.研究了PVA/PVP复合水凝胶的亲水性,测试了PVA/PVP复合水凝胶作为生物医用材料时的溶血性,结果显示其具有良好的生物相容性;3.PVA/PVP复合水凝胶的拉伸和压缩应力-应变呈现典型的非线性关系,是一种粘弹性材料。拉伸和压缩强度随着辐照剂量的增加,先增加后降低,随着冷冻解冻次数的增加而增加。在辐照剂量为100kGy时,拉伸和压缩强度达到最大值。拉伸模量和压缩模量均随应变的增加而增加;4.较全面地研究了不同条件下PVA/PVP复合水凝胶的生物摩擦学性能。考察了辐照剂量、润滑条件、冷冻解冻循环次数、载荷、PVA聚合度、PVP的添加、以及不同的摩擦副等因素对水凝胶摩擦学性能的影响。辐照后,摩擦系数呈现一定的上升变化趋势,但在100kGy时,摩擦系数反而较小。摩擦系数随着冷冻解冻循环次数的增加而增加。在小牛血清润滑下的摩擦系数较去离子水和生理盐水中最小;5.初步研究了PVA/PAAM复合水凝胶的制备,力学性能和摩擦学性能等,探讨了其作为一种新型关节软骨修复材料的可行性。6.制备的PVA/PVP复合水凝胶具有类似于天然关节软骨的力学性能和生物摩擦学性能,是一种很有前途的关节软骨修复材料。更多还原

【Abstract】 The injury of articular cartilage is a common form of the joint pain,and it’s a common disease in clinical orthopedics.There is an impetus for the development of an ideal material for articular cartilage repairing for a long time.Polyvinyl alcohol(PVA) hydrogel is a hydrogel not only with normal gel performance,but with low toxicity and good mechanical properties,high water absorption and the advantages of good biocompatibility.It’s a promising artificial cartilage repairing material.In order to improve the properties of PVA hydrogel as artificial cartilage repairing materials,the PVA/PVP gel composite was prepared combining the methods of freezing-thawing andγ-irradiation cross-linking.We prepared PVA/PAAM gel composite with freezing-thawing methods and investigated its the feasibility of it as artificial cartilage repairing materials.The micro-morphology and structure were characterized by many experimental techniques such as SEM and FTIR.The hydrophilicity,mechanical and biotribological properties of PVA/PVP gel composite were systemically studied.The hemolytic property of PVA/PVP gel composite was tested.The main contents and results are as follows:1.The PVA/PVP gel composite prepared by a combination of freezing-thawing andγ-irradiation methods had a porous structure similar to natural articular cartilage.Afterγ-irradiation,the toughness of PVA/PVP gel composite surface was improved and the internal network structure was strengthened,so the wear could be reduced.2.The hydrophilicity of PVA/PVP gel composite was studied.We also tested the hemolytic property of PVA/PVP gel composite as biomedical material.The result showed its good biocompatibility.3.The change behavior of tensile and compressive stress with the changes of strain shows a non-linear relationship.Both tensile strength and compressive strength of the composite increased firstly and then decreased with the rise of irradiation dose,increase with the rise of freezing-thawing cycle times.The tensile and compressive strength had the maximum value when the irradiation dose was 100kGy.The tensile and compressive modulus of the composite increased with the increase of strain.4.The biotribological properties of PVA/PVP gel composite under different conditions were studied.The factor such as irradiation dose,freezing-thawing cycle times,load,degree of PVA polymerization,addition of PVP and different wear counterparts all affected the gel’s properties.Friction coefficient had some changes after irradiation.Friction coefficient was relatively small when irradiation dose was 100kGy.And friction coefficient was increased alone with the increase of freezing-thawing cycle times.The friction coefficient of the gel composites was lower in bovine serum than that in distilled water and physiological saline.5.The preparation,mechanical and biotribological properties of PVA/PAAM gel composite were studied,and the feasibility of this composite as articular cartilage repairing material was explored.6.PVA/PVP gel composite had the mechanical and biotribological properties similar to natural cartilage.It’s a promising articular cartilage repairing material.更多还原