Li Xiaoting, Wang Qiaoying, Wei Qingrong
School of Medicine and Nursing, Leshan Vocational and Technical College, No. 1336, Middle Section of Qingjiang Avenue, Leshan 614000, China.
National Engineering Research Center for Biomaterials (NERCB), College of Biomedical Engineering, Sichuan University, Chengdu 610065, China.
Gels. 2024 Aug 25;10(9):550. doi: 10.3390/gels10090550.
The microstructure of bone consists of nano-hydroxyapatite (nano-HA) crystals aligned within the interspaces of collagen fibrils. To emulate this unique microstructure of bone, this work applied two biomimetic techniques to obtain bone-like microstructures in vitro, that is, combining the construction of collagen liquid crystal hydrogel (CLCH) with the application of a polymer-induced liquid precursor (PILP) mineralization process. Upon the elevation of pH, the collagen macromolecules within the collagen liquid crystal (CLC) were activated to self-assemble into CLCH, whose fibrils packed into a long and dense fiber bundle in high orientation, emulating the dense-packed matrix of bone. We demonstrated that the fibrillar mineralization of CLCH, leading to a bone-like nanostructured inorganic material part, can be achieved using the PILP crystallization process to pre-mineralize the dense collagen substrates of CLCH with CaCO, immediately followed by the in situ mineral phase transformation of CaCO into weak-crystalline nano-HA. The combination of CLCH with the biomineralization process of PILP, together with the mineral phase transformation, achieved the in vitro simulation of the nanostructures of both the organic extracellular matrix (ECM) and inorganic ECM of bone. This design would constitute a novel idea for the design of three-dimension biomimetic bone-like material blocks for clinical needs.
骨的微观结构由排列在胶原纤维间隙内的纳米羟基磷灰石（nano-HA）晶体组成。为了模拟骨的这种独特微观结构，本研究应用了两种仿生技术在体外获得类骨微观结构，即将胶原液晶水凝胶（CLCH）的构建与聚合物诱导液相前驱体（PILP）矿化过程相结合。随着pH值升高，胶原液晶（CLC）中的胶原大分子被激活并自组装成CLCH，其纤维以高取向堆积成长而致密的纤维束，模拟骨的紧密堆积基质。我们证明，CLCH的纤维状矿化可通过PILP结晶过程实现，该过程先用CaCO₃对CLCH的致密胶原底物进行预矿化，随后立即将CaCO₃原位矿相转变为弱结晶纳米HA，从而形成类骨纳米结构无机材料部分。CLCH与PILP生物矿化过程以及矿相转变相结合，实现了对骨的有机细胞外基质（ECM）和无机ECM纳米结构的体外模拟。这种设计将为临床需求的三维仿生类骨材料块的设计提供新思路。
