用不同种类异氰酸酯[脂肪族六亚甲基二异氰酸酯(HDI)和脂环族异佛尔酮二异氰酸酯(IPDI)]对聚己内酯(PCL)进行改性,得到两端为羟基的异氰酸酯改性的PCL预聚体.将未改性和改性的PCL端羟基进行磷酸化后[磷酸化组分PCL210磷酸酯(A)、PCL205/HDI磷酸酯(B)和PCL205/IPDI磷酸酯(C)]与双官能度的环氧(1,4-丁二醇二缩水甘油醚,E)进行开环交联反应,得到生物相容且可降解的聚己内酯型聚氨酯弹性体材料(AE,BE和CE).聚己内酯型聚氨酶弹性体的力学性能、静态水接触角、体外降解/溶胀和细胞毒性测试结果表明,PCL异氰酸酯的改性有助于提高材料的强度、弹性、耐疲劳性和降解速率,同时未明显提高材料的细胞毒性.
Polycaprolactone(PCL) is a kind of excellent histocompatible and biodegradable materials due to the presence of amounts of esters that can be hydrolyzed by water or enzyme,which made PCL as one of Pure Food and Drug Administration(FDA) certified medical materials. However,the high crystallinity and poor hydrophility of polycaprolactone induce slow biodegradation rate,poor tenacity and fatigue durability although it has high mechanical strength. Therefore,modification on polycaprolactone was necessary. Herein,we used isocyanates[hexamethylene diisocyanate(HDI) and isophorone diisocyanate(IPDI) ] to modify polycaprolactone and the phosphorylated prepolymers were reacted with bifunctional epoxy to form crosslinked and biodegradable elastomers. The test and analysis of mechanical properties,water contact angle,degradation/swelling and cell cytotoxicity in vitro indicated that the introduction of isocyanate helped to improve flexibility,fatigue resistance and degradation rate of the elastomers with no increased cytotoxicity.