【作者】 杜江华；

【导师】 杨青芳；

【作者基本信息】 西北工业大学 ， 材料学， 2007， 硕士

【摘要】 组织工程支架是组织工程中重要的研究对象之一，其支架在体内的降解速率能否与生长组织部位修复速率相匹配是组织工程支架能否临床应用的关键因素之一。聚β-羟基丁酸酯(PHB)是良好的组织工程支架材料之一，但降解速率较慢的特点影响了其在组织工程中的进一步应用。本文针对PHB降解速率慢的不足，从影响材料结晶度的因素考虑，将PHB与生物相容性好的聚乳酸(PLLA)及聚氧乙烯(PEO)共混改性，通过调整其比例以调控PHB的降解速率。另外，结合溶剂浇铸／粒子滤出法制备组织工程支架的优点，初步探讨研究了一种新的制备组织工程支架的方法，并考察了支架在动物体内的降解情况。 实验运用DSC、POM、SEM手段研究了PHB／PLLA及PHB／PLLA／PEO共混体系的相容性、冷结晶性及结晶度的变化情况及其在溶菌酶／PBS缓冲溶液中的降解情况，结果表明，PHB与PLLA有一定的相容性，PEO的加入提高了PHB与PLLA的相容性；PHB与PLLA共混，各组分的冷结晶温度不变，PHB的冷结晶速率不受PLLA的影响，而PLLA冷结晶速率随PHB含量增大而加快，共混体系的结晶度随PLLA的含量的增多而变小；对含有PEO的PHB／PLLA共混体系，PHB与PLLA的冷结晶温度都有减小；PLLA含量小于50％时，共混体系的降解速率要慢于纯的PHB，PLLA含量为50％时，PHB＜体系的降解速率＜PLLA，含有5％PEO的PHB／PLLA(1:1)共混体系降解速率显著提高，在实验90天前要快于PLLA，而后降解速率慢于PLLA，当体系降解120天后，PHB与PLLA的冷结晶温度几乎相同，说明PEO的加入加快了其体系的降解速度。 实验研究制备出由PHB多孔膜片与PHB／PLLA／PEO纤维复合而成的“夹芯”组织工程支架，并确定了制备PHB多孔膜片的最佳溶液浓度为2-3％：另外，将制备的“夹芯”支架植入兔子体内，SEM电镜观察，支架不但显示出了良好的组织相容性，而且降解显著；此外，该支架的结构也有利于细胞的生长。更多还原

【Abstract】 The three-dimensional scaffolds is one important part in the study of tissue engineering, whether the scaffolds rate of degradation in vivo can match with the growth rate of repair tissue is one of the key factors which scaffolds are applied in the clinical treatment.poly(β-hydroxybutyrate)(PHB) is one of good biomaterials for tissue engineer -ing.however, the slow rate of degradation of the characteristics of its impact on the further application in tissue engineering. In this paper, poly(L-lactide)(PLLA), poly(ethyleneoxide)(PEO),and PHB was blended, attempting to improve slow de-g radation. The material’s degradability was improved by adjusting the rate of blending. In addition, a new method was developed to prepare highly porous biodegradable scaffolds for tissue engineering, and the scaffolds was implanted in thea nimal body to observe its degradability.The cold crystallization behavior ,miscibility, crystallinity and degradability in the lysozyme/PBS buffer solution, of PHB/PLLA blends and PHB/PLLA/PEO ble -nds was studied by differential scanning calorimetry(DSC),Polarizing Optical Mcr oscopy(POM), Scanning Electron Microscopy(SEM).The results showed that, PHB was partly compatible with PLLA, and the miscibility of PHB with PLLA could be improved when PEO joining in the PHB/PLLA blends;the cold crystallizationt emperature and rate of PHB were independent of contents of PLLA in blends, a nd the cold crystallization temperatue of PLLA was also not affected by PHB, h owever, the crystallization rate became faster with increasing contents of PHB in blends; the crystallinity of blends depends on ratio of PHB and PLLA; In PHB/ PLLA/PEO blends, the cold crystallization temperature of PHB and PLLA were reduced .When PHB/PLLA blends containing less than 50% weights PLLA, thera te of blends degradation was slower than pure PHB;When containing up to 50% weights PLLA.the rate of the blends degradation was faster than pure PHB, but slower than pure PLLA; For blends PHB/PLLA/PEO containing 5% PEO, its ra te of degradation become faster in compared with PHB and PHB/PLLA blends,b efore 90 days, its rate was faster than that of pure PLLA, after 90 days.its rate was behind of pure PLLA, and remained PHB and PLLA became nearly miscibl更多还原