Shen Hong, Hu Xixue, Yang Fei, Bei Jianzhong, Wang Shenguo
BNLMS, State Key Laboratory of Polymer Physics & Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China.
Biomaterials. 2007 Oct;28(29):4219-30. doi: 10.1016/j.biomaterials.2007.06.004. Epub 2007 Jul 5.
Surface characteristics greatly influence attachment and growth of cells on biomaterials. Although polylactone-type biodegradable polymers have been widely used as scaffold materials for tissue engineering, lack of cell recognition sites, poor hydrophilicity and low surface energy lead to a bad cell affinity of the polymers, which limit the usage of polymers as scaffolds in tissue engineering. In the present study, surface of poly (L-lactide-co-glycolide) (PLGA) was modified by a method of combining oxygen plasma treatment with anchorage of cationized gelatin. Modification effect of the method was compared with other methods of oxygen plasma treatment, cationized gelatin or gelatin coating and combining oxygen plasma treatment with anchorage of gelatin. The change of surface property was compared by contact angles, surface energy, X-ray photoelectron spectra (XPS), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) measurement. The optimum oxygen pretreatment time determined by surface energy was 10 min when the power was 50 W and the oxygen pressure was 20 Pa. Analysis of the stability of gelatin and cationized gelatin anchored on PLGA by XPS, ATR-FTIR, contact angles and surface energy measurement indicated the cationized gelatin was more stable than gelatin. The result using mouse NIH 3T3 fibroblasts as model cells to evaluate cell affinity in vitro showed the cationized gelatin-anchored PLGA (OCG-PLGA) was more favorable for cell attachment and growth than oxygen plasma treated PLGA (O-PLGA) and gelatin-anchored PLGA (OG-PLGA). Moreover cell affinity of OCG-PLGA could match that of collagen-anchored PLGA (AC-PLGA). So the surface modification method combining oxygen plasma treatment with anchorage of cationized gelatin provides a universally effective way to enhance cell affinity of polylactone-type biodegradable polymers.
表面特性极大地影响细胞在生物材料上的附着和生长。尽管聚内酯型可生物降解聚合物已被广泛用作组织工程的支架材料，但缺乏细胞识别位点、亲水性差和表面能低导致这些聚合物的细胞亲和力不佳，这限制了它们在组织工程中作为支架的应用。在本研究中，聚（L-丙交酯-共-乙交酯）（PLGA）的表面通过氧等离子体处理与阳离子化明胶固定相结合的方法进行了改性。将该方法的改性效果与其他氧等离子体处理、阳离子化明胶或明胶涂层以及氧等离子体处理与明胶固定相结合的方法进行了比较。通过接触角、表面能、X射线光电子能谱（XPS）、衰减全反射-傅里叶变换红外光谱（ATR-FTIR）和扫描电子显微镜（SEM）测量来比较表面性质的变化。当功率为50 W且氧气压力为20 Pa时，由表面能确定的最佳氧预处理时间为10分钟。通过XPS、ATR-FTIR、接触角和表面能测量对固定在PLGA上的明胶和阳离子化明胶的稳定性进行分析，结果表明阳离子化明胶比明胶更稳定。以小鼠NIH 3T3成纤维细胞作为模型细胞进行体外细胞亲和力评估的结果表明，阳离子化明胶固定的PLGA（OCG-PLGA）比氧等离子体处理的PLGA（O-PLGA）和明胶固定的PLGA（OG-PLGA）更有利于细胞附着和生长。此外，OCG-PLGA的细胞亲和力可与胶原固定的PLGA（AC-PLGA）相匹配。因此，氧等离子体处理与阳离子化明胶固定相结合的表面改性方法为提高聚内酯型可生物降解聚合物的细胞亲和力提供了一种普遍有效的方法。
