Du Tianming, Niu Yumiao, Liu Youjun, Yang Haisheng, Qiao Aike, Niu Xufeng
Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Department of Biomedical Engineering, Faculty of Environment and Life, Beijing University of Technology, Beijing 100124, China.
Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
J Funct Biomater. 2022 May 13;13(2):57. doi: 10.3390/jfb13020057.
Mineralized collagen is the basic unit in hierarchically organized natural bone with different structures. Polyacrylic acid (PAA) and periodic fluid shear stress (FSS) are the most common chemical and physical means to induce intrafibrillar mineralization. In the present study, non-mineralized collagen, extrafibrillar mineralized (EM) collagen, intrafibrillar mineralized (IM) collagen, and hierarchical intrafibrillar mineralized (HIM) collagen induced by PAA and FSS were prepared, respectively. The physical and chemical properties of these mineralized collagens with different microstructures were systematically investigated afterwards. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that mineralized collagen with different microstructures was prepared successfully. The pore density of the mineralized collagen scaffold is higher under the action of periodic FSS. Fourier transform infrared spectroscopy (FTIR) analysis showed the formation of the hydroxyapatite (HA) crystal. A significant improvement in the pore density, hydrophilicity, enzymatic stability, and thermal stability of the mineralized collagen indicated that the IM collagen under the action of periodic FSS was beneficial for maintaining collagen activity. HIM collagen fibers, which are prepared under the co-action of periodic FSS and sodium tripolyphosphate (TPP), may pave the way for new bone substitute material applications.
矿化胶原蛋白是具有不同结构的分层组织天然骨中的基本单元。聚丙烯酸（PAA）和周期性流体剪切应力（FSS）是诱导纤维内矿化最常用的化学和物理手段。在本研究中，分别制备了由PAA和FSS诱导的非矿化胶原蛋白、纤维外矿化（EM）胶原蛋白、纤维内矿化（IM）胶原蛋白和分层纤维内矿化（HIM）胶原蛋白。随后系统研究了这些具有不同微观结构的矿化胶原蛋白的物理和化学性质。透射电子显微镜（TEM）和扫描电子显微镜（SEM）表明成功制备了具有不同微观结构的矿化胶原蛋白。在周期性FSS作用下，矿化胶原蛋白支架的孔隙密度更高。傅里叶变换红外光谱（FTIR）分析表明形成了羟基磷灰石（HA）晶体。矿化胶原蛋白的孔隙密度、亲水性、酶稳定性和热稳定性有显著改善，表明周期性FSS作用下的IM胶原蛋白有利于维持胶原蛋白活性。在周期性FSS和三聚磷酸钠（TPP）共同作用下制备的HIM胶原纤维可能为新型骨替代材料的应用铺平道路。
