Hu Yingqian, Zhu K J
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China.
J Biomater Sci Polym Ed. 2003;14(12):1363-76. doi: 10.1163/156856203322599707.
Degradable terpolymers were synthesized by bulk copolymerization of 2,2-dimethyl trimethyle necarbonate (DTC), epsilon-caprolactone (CL) and poly(ethylene glycol) (PEG) using stannous octoate as catalyst at 140 degrees C for 36 h. The molar ratio in feed of DTC to CL was fixed at 20:80. The molecular weight and the mol% of PEG were varied in order to obtain copolymers with different properties. The copolymers were characterized by 1H-NMR, 13C-NMR, FT-IR, GPC and DSC. It was found that the hydrophilicity of these materials increased with increasing PEG content in the copolymers, according to the measurements of static contact angles of distilled water on the surface of polymer films. Mechanical tests and hydrolytic degradation assays showed that copolymers of different degradability and mechanical properties could be tailored by adjusting the compositions. For the copolymer T-4 (11.9 mol% of PEG with Mn 2000), the tensile strength and the elastic modulus could reach 6.2 MPa and 25 MPa, respectively. It took only 4 weeks for the copolymer T-4 to degrade to 83% (M(n,t)/M(n,0)) and 10 weeks to 63% in 0.1 M PBS at pH 7.4 and 37 degrees C. There was no obvious acceleration of degradation rate in vivo in comparison with that in vitro. These materials might be useful for nerve regeneration guides and other biomedical applications.
以辛酸亚锡为催化剂，通过2,2 - 二甲基三亚甲基碳酸酯（DTC）、ε-己内酯（CL）和聚乙二醇（PEG）的本体共聚反应，在140℃下合成可降解三元共聚物36小时。DTC与CL的进料摩尔比固定为20:80。改变PEG的分子量和摩尔百分比以获得具有不同性能的共聚物。通过1H-NMR、13C-NMR、FT-IR、GPC和DSC对共聚物进行表征。根据蒸馏水在聚合物薄膜表面的静态接触角测量结果发现，这些材料的亲水性随着共聚物中PEG含量的增加而增加。力学测试和水解降解试验表明，通过调整组成可以定制具有不同降解性和力学性能的共聚物。对于共聚物T - 4（PEG含量为11.9摩尔％，Mn为2000），拉伸强度和弹性模量分别可达6.2 MPa和25 MPa。在pH 7.4和37℃的0.1 M PBS中，共聚物T - 4仅需4周降解至83％（M(n,t)/M(n,0)），10周降解至63％。与体外相比，体内降解速率没有明显加快。这些材料可能对神经再生引导物和其他生物医学应用有用。
