聚(ε-己内酯)/赖氨酸二异氰酸酯基可降解聚氨酯的合成与表征及其电纺丝研究

Synthesis,Characterization and Electrospinning of Biodegradable Polyurethanes Based on Poly(ε-caprolactone) and L-Lysine Diisocynate

首先合成了一种新型的氨基酸类二异氰酸酯,即L-赖氨酸乙酯二异氰酸酯（LDI）。然后,将分子量为2 000的聚（ε-己内酯）二元醇（PCL）与LDI反应生成预聚物,再与扩链剂1,4-丁二醇（BDO）反应合成聚氨酯（PU）。对PU进行了分子量、红外和核磁共振的表征,力学性能测试表明此PU具有良好的机械性能,PU的水解降解和酶促降解实验表明PU具有可降解性。最后,对PU做为组织工程血管支架的电纺丝加工性能进行了研究,电纺丝管状支架的拉伸强度可达8 MPa,缝合强度为12 N,孔隙率为75%,爆破压可达150~170 kPa,毒性较小,有利于细胞生长,符合组织工程血管支架的要求。

A novel diisocyanate,i.e.lysine ethyl ester diisocyanate（LDI）,was prepared by the present authors.Poly（ε-caprolactone）（PCL）（Mn=2000） was used for reacting with LDI to form prepolymer,and then the chain was extended with butanediol（BDO） to form polyurethane（PU）.PU was characterized by gel permeation chromatography,FTIR and 1H-NMR.Mechanical properties test revealed that PU possesses excellent tensile strength.Hydrolytic degradation and enzymatic degradation of PU films showed that PU is biodegradable.Finally,vascular scaffold of PU was fabricated by electrospinning.Morphological and biomechanical properties of scaffold were examined.The tensile strength was 8MPa,suture retention strength 12N,porosity 75% and burst pressure strength 150-170kPa.Cytotoxicity and cell adhesion showed that PU scaffolds are biocompatible. These results demonstrate that PU vascular scaffolds possess excellent physical strength and biocompatibility and can be developed as substitutes for native blood vessels.