聚羟基脂肪酸酯的亲水性改性及其与人脐静脉内皮细胞相容性的研究

BIOCOMPATIBILITY OF PHBHHx AND SILK FIBROIN-MODIFIED PHBHHx SCAFFOLDS WITH HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS

用丝素蛋白(SF)对微生物合成的高分子聚合物聚(3-羟基丁酸酯-co-3-羟基己酸酯)(PHBHHx)进行亲水改性,以提高材料的生物相容性.水接触角测定和表面自由能分析表明,丝素蛋白在支架表面吸附,使PHBHHx材料表面的水接触角从90°降至51°,表面自由能从37.9 mJ/m2增至57.4 mJ/m2,因而增加了材料的亲水性.进一步对亲水性改性前后PHBHHx多孔支架与人脐静脉内皮细胞(HUVECs)的相容性进行了比较.MTT法细胞活力分析表明,细胞在支架上培养3,5,7天后,其在SF改性PHBHHx多孔支架上的活力显著高于在未改性的PHBHHx支架上的活力;扫描电镜观察细胞生长形貌表明,细胞在改性后多孔支架上黏附及生长5天后,形成了连续细胞单层,其生长状态优于在未改性的PHBHHx支架上的生长状态;胶原含量测定表明细胞在改性后支架上比在未改性支架上有更好的胶原分泌能力,即改性后支架更利于诱导HUVECs分泌细胞外基质(ECM)从而构建类似体内的生长环境.

Silk fibroin （SF） was used to enhance the biocompatibility of poly （3-hydroxybutyrate-co-3- hydroxylhexnoate） （PHBHHx） porous scaffold through surface-coating. The decrease in the water contact angle from 90° to 51°and the increase in the surface free energy from 37.9 mJ/m^2to 57.4 mJ/m^2 on the basis of comparison of SF modified PHBHHx films with SF un-modified ones,respectively, demonstrated that SF was successfully anchored on the surface of PHBHHx,enhancing the PHBHHx hydrophilicity. In order to verify the influence of the modification on the cells growth,the human umbilical vein endothelial cells （HUVECs） were seeded on the SF/PHBHHx scaffolds with un-modified PHBHHx scaffolds as control. MTT assay quantitatively demonstrated that HUVECs adhered faster and proliferated better on the SF/PHBHHx porous scaffolds than on the un-modified PHBHHx scaffolds at day 3,5 and 7. The cell morphologies observed by SEM at day 5 indicated that HUVECs formed continuous cell monolayer on the SF/PHBHHx scaffolds,while they did not on the un-modified PHBHHx scaffolds. Also, the higher collagen content on the modified scaffolds demonstrated that more extracellular matrices （ECM） were secreted by HUVECs similar to the environment of the cell growing in vivo. Therefore, the SF-modified PHBHHx is potential to be applied into the cardiovascular tissue engineering.