纤维素/海藻酸钠复合气凝胶的表面功能化与仿生矿化  

Biomineralization and Surface Functionalization of Cellulose/Sodium Alginate Composite Aerogels

作　　者：査莉 王璐瑶 郑雅慧 车剑飞[1] ZHA Li;WANG Luyao;ZHENG Yahui;CHE Jianfei(School of Chemical Engineering,Nanjing University of Science&Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学化工学院,南京210094

出　　处：《功能高分子学报》2020年第4期382-389,共8页Journal of Functional Polymers

基　　金：国家自然科学基金(51803092)。

摘　　要：通过高碘酸钠和亚氯酸钠的2次氧化法,对纤维素/海藻酸钠复合气凝胶进行表面氧化改性,将纤维素和海藻酸钠表面C2和C3位置的羟基氧化为羧基,有效地提高了复合气凝胶的矿化能力。通过傅里叶红外光谱仪(FT-IR)、扫描电镜(SEM)、X射线衍射仪(XRD)、X射线光电子能谱仪(XPS)、体外细胞毒性测试等对羧基化改性前后在复合气凝胶支架上的沉积物进行表征。结果表明,改性后复合气凝胶表面的磷灰石形成速率更快,晶粒更小,沉积层更均匀;改性复合气凝胶表面的羧基具有更强的Ca^2+结合能力,可以诱导Ca^2+吸附在气凝胶表面,使矿化能力提高。同时,小鼠成纤维细胞实验表明,矿化后的复合气凝胶无毒性,可以促进细胞生长和分化,是性能良好的骨组织工程材料。Cellulose/sodium alginate(Cellu/SA)composite aerogels were prepared via freeze-drying technique as a valid method to develop 3D scaffolds for tissue engineering.Cellulose with hydroxyl groups showed weak apatite nucleation ability in simulated body fluid(SBF).In order to induce the formation of apatite crystal,oxidation modification of Cellu/SA composite aerogels was carried out with sodium periodate and sodium chlorite.The hydroxyl groups at C2 and C3 of Cellulose and SA were oxidized into carboxyl groups,leading to improve mineralization ability.The morphology and structure were characterized by Fourier Transform Infrared(FT-IR)spectrometer,Scan Electron Microscope(SEM),X-Ray Diffraction(XRD)and X-ray photoelectron spectroscopy.Results show that the formation of HA on the surface of dicarboxylic Cellu/SA composite aerogels is faster with smaller grain size,and the deposition layer is more uniform after mineralization for 7 d.The Cellu/SA composite aerogels thus possess an ultrafine 3D nanoporous network structure.It is noticeable that the dicarboxylic Cellu/SA composite aerogel is a promising candidate for orthopedic biomaterial application with a Ca/P molar ratio of 1.35.In addition,the aerogel has good biocompatibility demonstrated by CCK8 assay and Live/Dead fluorescence staining of L929 cells.The L929 cells activity of both Cellu/SA and dicarboxylic Cellu/SA composite aerogels extracts are higher than 80%.When the culture duration is prolonged to 72 h,an obvious increase in the intensity of green fluorescence is observed,suggesting that the number of cells is increased.The biocompatible mineralized dicarboxylic Cellu/SA composite aerogels can promote cell growth and differentiation and are potential to be applied as a bone repair material.

关 键 词：纤维素 海藻酸钠 气凝胶 羧基化改性 仿生矿化 

分 类 号：R318[医药卫生—生物医学工程]