Cai Qing, Wan Yuqing, Bei Jianzhong, Wang Shenguo
PCLCC and Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
Biomaterials. 2003 Sep;24(20):3555-62. doi: 10.1016/s0142-9612(03)00199-6.
Brush-like biodegradable polylactide-grafted dextran copolymer (PLA-g-dextran) was by a bulk polymerization reaction using a trimethylsilyl-protected (TMS) dextran as macroinitiator and stannous octoate as catalyst. After the polymerization, the TMS groups could be easily removed by immersing the copolymer in methanol for 48 h. The PLA-g-dextran copolymers were characterized by (1)H NMR, GPC and intrinsic viscosity measurements. Besides, mouse 3T3 fibroblasts were cultured on these copolymeric substrates together with pure polylactide (PLA). Although the copolymers exhibited better hydrophilicity and cell affinity compared to pure PLA because of the incorporation of glucose units and the brush-like architecture, it was found that the cells still could not migrate into the center part of scaffold made of PLA-g-dextran copolymer. In result, PLA-g-dextran copolymers themselves were not an appropriate choice for the cell scaffold material, however, it could be used as compatilizer to ameliorate the compatibility between hydrophilic dextran and hydrophobic PLA due to its amphiphilic structure, which could improve the mechanical properties of PLA/dextran blends by reducing the phase separation between PLA and dextran. Therefore, the PLA/dextran blends, which had good cell affinity and moderate mechanical strength, might be prospect cell scaffold materials.
刷状可生物降解聚丙交酯接枝葡聚糖共聚物（PLA-g-葡聚糖）通过本体聚合反应制备，使用三甲基硅烷基保护的（TMS）葡聚糖作为大分子引发剂，辛酸亚锡作为催化剂。聚合反应后，通过将共聚物浸入甲醇中48小时可轻松除去TMS基团。通过1H NMR、凝胶渗透色谱法（GPC）和特性粘度测量对PLA-g-葡聚糖共聚物进行了表征。此外，将小鼠3T3成纤维细胞与纯聚丙交酯（PLA）一起培养在这些共聚物基质上。尽管由于葡萄糖单元的引入和刷状结构，共聚物比纯PLA表现出更好的亲水性和细胞亲和力，但发现细胞仍无法迁移到由PLA-g-葡聚糖共聚物制成的支架中心部分。结果，PLA-g-葡聚糖共聚物本身不是细胞支架材料的合适选择，然而，由于其两亲结构，它可用作增容剂以改善亲水性葡聚糖和疏水性PLA之间的相容性，这可以通过减少PLA和葡聚糖之间的相分离来提高PLA/葡聚糖共混物的机械性能。因此，具有良好细胞亲和力和适度机械强度的PLA/葡聚糖共混物可能是有前景的细胞支架材料。
