类肝素超支化聚醚的制备、组装及其生物相容性的研究

SYNTHESIS AND SELF-ASSEMBLY OF SULFONATED HYPERBRANCHED POLYETHERS AND THEIR BIOCOMPATIBILITY

利用超支化的聚(3-乙基-3-羟甲基氧杂环丁烷)(HBPO)与1,3-丙烷磺内酯反应,制备了磺酸基修饰的水溶性的类肝素超支化聚醚(HBPO-SO3),1H-NMR和FTIR表征产物具有预期的结构.通过粒径分析仪、透射电镜(TEM)和荧光探针对聚合物在水溶液中的自组装行为进行表征,证明当HBPO-SO3在水溶液中的浓度大于0.017mg/mL时,可形成尺寸在25～70nm之间的具有疏水内核的胶束.复钙化凝血时间(PRT)的测定证明这种类肝素超支化聚醚具有良好的抗凝血性能,体外细胞活性测定和细胞形貌观察证明其具有良好的细胞相容性.

A novel water soluble sulfonated hyperbranched polyether （HBPO-SO3）, consisting of a hydrophobic hyperbranched poly （3-ethyl-3-oxetanemethanol） core and many sulfonate terminal groups, was designed as a promising heparin-like biomaterial. The mieelle formation of the resultant HBPO-SO3 in aqueous solutions was monitored by fluorescence spectroscopy using pyrene as a hydrophobie probe, and the critical micelle concentration （CMC） was determined to be 0.017 mg/mL. The analyses of transmission electron microscopy （TEM） clearly showed that all the sulfonated hyperbranehed polyether samples aggregated into spherical micelles with diameters of 25- 70 nm. The mean diameter of micelles determined by the laser scattering particle size distribution analyzer is about 32.5 nm. Compared with the saline solution used as a control in the plasma recalcification time （PRT） assay, both HBPO-SO3 micelles solution and unimolecular micelles solution could reduce blood clotting. In the case of HBPO-SO3 at a concentration of 0.33 mg/mL,there were no signs of clotting even after 1 h.The toxicity of HBPOSO3 was assessed in vitro with ECV-304 cells using MTT method and found to be nontoxic for 48 h incubation up to a 0.1 mg/mL concentration. The cell morphology was also observed by confocal laser scanning microscope （CLSM）. The results of CLSM revealed that the culture media containing HBPO-SO3 up to 0.1 mg/mL had no negative effect on the attachment and proliferation of cells, compared with the control. Results from the PRT assay and cell culture declared that both HBPO-SO3 micelles and the unimolecular micelles exhibited good hemocompatibility and low cytotoxicity. These experimental results suggest that HBPO-SO3 could be a good candidate for hydrophobic drug carriers.