Huang Qian, Hao Liying, Xie Jing, Gong Tao, Liao Jinfeng, Lin Yunfeng
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University , Chengdu 610041, People's Republic of China.
ACS Appl Mater Interfaces. 2015 Sep 23;7(37):20893-901. doi: 10.1021/acsami.5b06300. Epub 2015 Sep 11.
In this study, water-soluble, one-step highly reduced and functionalized graphene oxide was prepared via a facile, environment-friendly method by using tea polyphenol (TP), which acted as both reducing agent and stabilizer. The product obtained, that is, tea polyphenol-reduced graphene oxide (TPG), was used as a reinforcing building block for the modification of a mechanically weak chitosan (CS), TPG/CS. The morphology and physicochemical and mechanical properties of the composite were examined by various characterizations. The tensile strength and elastic modulus of CS were greatly improved by TPG, as compared to the findings for GO incorporation. Additionally, to our knowledge, this study is an in-depth analysis of the osteoblast functions of CS/TPG, including aspects such as cell cytotoxicity, proliferation, and expression of ossification genes, alkaline phosphatase (ALP), and Runt-related transcription factor (Runx2), which showed advantages in favorably modulating cellular activity. It was concluded that TPG/CS showed a higher elastic modulus, better hydrophilicity, and excellent biocompatibility than the pristine chitosan for promoting the proliferation and differentiation of osteoblasts, as well as for accelerating the expression of ALP and Runx2 (as shown by reverse transcription polymerase chain reaction (RT-PCR)). These results may provide new prospects for the use of TPG in the modification of biomaterials and for broadening the application of TPG in biological fields.
在本研究中，通过一种简便、环保的方法，利用兼具还原剂和稳定剂作用的茶多酚（TP）制备了水溶性、一步法高度还原且功能化的氧化石墨烯。所得到的产物，即茶多酚还原氧化石墨烯（TPG），被用作增强结构单元，用于对机械性能较弱的壳聚糖（CS）进行改性，即TPG/CS。通过各种表征手段对该复合材料的形态、物理化学和机械性能进行了研究。与氧化石墨烯掺入的结果相比，TPG使CS的拉伸强度和弹性模量有了显著提高。此外，据我们所知，本研究对CS/TPG的成骨细胞功能进行了深入分析，包括细胞毒性、增殖以及骨化基因、碱性磷酸酶（ALP）和Runt相关转录因子（Runx2）的表达等方面，结果表明其在有利调节细胞活性方面具有优势。得出的结论是，与原始壳聚糖相比，TPG/CS表现出更高的弹性模量、更好的亲水性和优异的生物相容性，有利于促进成骨细胞的增殖和分化，以及加速ALP和Runx2的表达（逆转录聚合酶链反应（RT-PCR）结果显示）。这些结果可能为TPG在生物材料改性中的应用以及拓宽其在生物领域的应用提供新的前景。
