活性氧响应性可降解不饱和聚氨酯的合成及其性能研究

Synthesis and Properties of ROS-responsive Biodegradable Polyurethanes with Unsaturated Double Bonds

设计合成了一类具有活性氧(ROS)响应性的新型不饱和聚氨酯. 3种不同比例的聚富马酸丙二醇酯(PPF)和聚酮缩硫醇(PTK)与六亚甲基二异氰酸酯(HDI)反应后,通过L-赖氨酸甲酯二盐酸盐(Lys-OMe)扩链,合成了含有双键和酮缩硫醇键的聚氨酯(PFTU),同时合成了只含有双键的聚氨酯(PPFU)和只含有酮缩硫醇键的聚氨酯(PTKU)作为对照.示差扫描量热分析(DSC)和热重分析(TGA)显示5种聚氨酯材料均为非晶态聚合物且在200℃以下具有良好的热稳定性.应力应变曲线显示PPFU是一种硬而韧的材料,而PTK的引入则改善了聚氨酯的弹性并使其保留良好的延伸性能.同时,含有PTK软段的聚氨酯PFTU和PTKU均具有较好的自由基清除能力;随着聚氨酯中PTK比例的增加,材料在过氧化氢/CuCl2溶液中的降解速率也逐渐增大.体外细胞培养实验表明,本文合成的5种聚氨酯材料均不存在明显的细胞毒性.

A novel type of unsaturated polyurethane with reactive oxygen species(ROS) responsiveness was designed and synthesized. Poly(propylene fumarate)(PPF) and poly(thioketal)(PTK) were selected as the soft segments to react with 1, 6-hexamethylene diisocyanate(HDI). The formed prepolymers were chain-extended with L-lysine methyl ester hydrochloride(Lys-OMe) to obtain the polyurethanes(PFTU) that possesses both double bonds and thioketal bonds in its structure. As a comparison, the polyurethanes, i.e. PPFU containing only double bonds and PTKU containing only thiolketal bonds were also synthesized. Differential scanning calorimetry(DSC) tests and thermogravimetric analysis(TGA) showed that the five kinds of polyurethane materials were amorphous and had a good thermal stability under 200 ℃. Stress-strain curves showed that the PPFU were a kind of material with hard and tough properties. The introduction of PTK segments improved the elasticity, and kept the good elongation property of polyurethane. The polyurethanes(PFTU and PTKU)containing PTK segments had much better free radical scavenging ability than the PPFU. With the increase of PTK ratio in the polyurethanes, the degradation rate of the materials in hydrogen peroxide/CuCl2 solution also increased gradually. In addition, results of cytotoxicity test in vitro demonstrated that all the polyurethane materials synthesized in this work did not exhibit obvious cytotoxicity.