Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan, ROC.
J Biomater Sci Polym Ed. 2012;23(1-4):233-50. doi: 10.1163/092050610X547001. Epub 2011 Jan 18.
Many studies have tried to look for the application of chitosan in tissue engineering since its structure is similar to glycoaminoglycans, the main components of the extracellular matrix. Previous studies had indicated that the incorporation of sulfonic or phosphonic functionalities would be beneficial to the growth of certain cells. However, no study has explored the effect of incorporation of both above-mentioned anionic functionalities onto the chitosan structure. In this study, we have surface-phosphorylated the polyelectrolyte film formed by chitosan and water-soluble sulfonated chitosan with the aim to incorporate phosphonic and sulfonic functionalities onto the film surface. Surface analyses by ESCA and ATR-FT-IR have shown that these two functional groups have been successfully grafted onto the surface, and that the ratio of P/S was dependent upon the weight ratio of phosphorylation agents added. Blood compatibility evaluation indicated that phosphorylated polyelectrolyte complexes extended the plasma recalcification time as compared to non-treated chitosan and direct-phosphorylated chitosan film. In addition, these phosphorylated polyelectrolyte complexes showed similar or slightly less platelet reactivity than the non-phosphorylated counterpart. In contrast, significant platelet activation and adhesion were noted on the direct-phosphorylated chitosan. This implicated the incorporation of sulfonic acid onto the phosphorylated surface can increase the platelet compatibility. An adipose-derived stem cell incubation study has demonstrated that the incorporation of both phosphonic and sulfonic acid functionalities onto the chitosan surface can enhance the stem cell growth. Therefore, the phosphorylated polyelectrolyte complexes were not only blood compatible but also stem cell compatible, and could be a novel biomaterial in tissue-engineering applications.
许多研究试图寻找壳聚糖在组织工程中的应用，因为它的结构类似于糖胺聚糖，是细胞外基质的主要成分。以前的研究表明，掺入磺酸基或磷酸基官能团将有利于某些细胞的生长。然而，尚无研究探索将这两种阴离子官能团同时掺入壳聚糖结构中的效果。在这项研究中，我们对壳聚糖和水溶性磺化壳聚糖形成的聚电解质膜进行了表面磷酸化，目的是将磷酸基和磺酸基官能团掺入膜表面。ESCA 和 ATR-FT-IR 的表面分析表明，这两种官能团已成功接枝到表面上，并且 P/S 比取决于添加的磷酸化剂的重量比。血液相容性评估表明，与未经处理的壳聚糖和直接磷酸化的壳聚糖膜相比，磷酸化的聚电解质复合物延长了血浆再钙化时间。此外，这些磷酸化的聚电解质复合物的血小板反应性与非磷酸化的对应物相似或略低。相比之下，直接磷酸化的壳聚糖上明显观察到血小板的激活和黏附。这表明磺酸基的掺入可以提高血小板的相容性。脂肪来源的干细胞孵育研究表明，将磷酸基和磺酸基官能团同时掺入壳聚糖表面可以增强干细胞的生长。因此，磷酸化的聚电解质复合物不仅具有血液相容性，而且具有干细胞相容性，可作为组织工程应用中的新型生物材料。
