聚乙二醇对羟基丁酸和羟基己酸共聚物的共混改性研究

本研究以聚羟基脂肪酸酯家族中的新成员羟基丁酸和羟基己酸共聚物（PHBHHx）为基础，采用与聚乙二醇（PEG）共混的方法对其进行改性，研究结果证实：PHBHHx与PEG 共混物中比例为3:1及2:1时，两者完全物理相容。而PEG在共混物中比例升高时则导致相分离，成为部分相容体系。PEG掺入显著提高材料亲水性及表面自由能，使血管平滑肌细胞（RaSMCs）及血管内皮细胞（HUVECs）的细胞粘附及增殖大幅度提高，并且均具有一定的PEG含量依赖性。其中对RaSMCs的作用最为明显，RaSMCs能在PEG/PHBHHx比例为1:1的共混膜（E1X1）上持续增殖至融合，而HUVECs则呈粘附较差的类球形形貌，证实E1X1可以潜在应用于复合血管组织工程支架中的近内膜基材。

Cellular Compatibility of Blends Consisting of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) and Polyethylene Glycol

Polyhydroxyalkanoates (PHAs) are a family of biodegradable polyesters, which are generally biodegradable and biocompatible and possess various plastic and elastomeric material properties depending on their monomer constituents. One PHA family member, namely, copolyesters of 3-hydroxybutyrate and 3-hydroxyhexanoate (PHBHHx) showed better mechanical properties compared with poly (3-hydroxybutyrate) (PHB) and poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In order to extend the potential application of PHBHHx in vascular-related tissue engineering, surface modification of PHBHHx were made by blending with polyethylene glycol (PEG). When PHBHHx was blended with PEG in ratios of 3:1 and 2:1, the two materials were miscible. When the ratio of PEG in the blends increased, phase separation appeared and the materials became partially miscible. Blending with PEG increased the hydrophilicity and surface energy of PHBHHx, leading to significantly enhancement of attachment and proliferation of RaSMCs and HUVECs in a PEG dose dependent way. Specially, PHBHHx blending with PEG in ratio of 1:1 promoted RaSMCs' proliferation compared with HUVECs'. These results suggest that PHBHHx blended with PEG in this way is promising in constructing complex multilayer vascular grafts.