Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Advanced Centre for Materials Science, Indian Institute of Technology Kanpur, Kanpur 208016, India.
ACS Biomater Sci Eng. 2022 Aug 8;8(8):3162-3186. doi: 10.1021/acsbiomaterials.2c00140. Epub 2022 Jul 15.
Being a bioactive material, hydroxyapatite (HAp) is regarded as one of the most attractive ceramic biomaterials for bone and hard-tissue replacement and regeneration. Despite its substantial biocompatibility, osteoconductivity, and compositional similarity to that of bone, the employment of HAp is still limited in orthopedic applications due to its poor mechanical (low fracture toughness and bending strength) and antibacterial properties. These significant challenges lead to the notion of developing novel HAp-based composites via different fabrication routes. HAp, when efficaciously combined with functionally graded materials and antibacterial agents, like Ag, ZnO, Co, etc., form composites that render remarkable crack resistance and toughening, as well as enhance its bactericidal efficacy. The addition of different materials and a fabrication method, like 3D printing, greatly influence the porosity of the structure and, in turn, control cell adhesion, thereby enabling biological fixation of the material. This article encompasses an elaborate discussion on different multifunctional HAp composites developed for orthopedic applications with particular emphasis on the incorporation of functionally graded materials and antibacterial agents. The influence of 3D printing on the fabrication of HAp-based scaffolds, and the different in vitro and in vivo studies conducted on these, have all been included here. Furthermore, the present review not only provides insights and broad understanding by elucidating recent advancements toward 4D printing but also directs the reader to future research directions in design and application of HAp-based composite coatings and scaffolds.
作为一种生物活性材料，羟基磷灰石（HAp）被认为是最具吸引力的陶瓷生物材料之一，可用于骨骼和硬组织的替代和再生。尽管 HAp 具有很高的生物相容性、骨诱导性和与骨相似的成分，但由于其机械性能差（低断裂韧性和弯曲强度）和抗菌性能，其在骨科应用中的应用仍然受到限制。这些重大挑战促使人们通过不同的制造途径开发新型 HAp 基复合材料。通过将 HAp 与功能梯度材料和抗菌剂（如 Ag、ZnO、Co 等）有效结合，形成复合材料，可显著提高抗裂性和韧性，并增强其杀菌效果。不同材料的添加和制造方法（如 3D 打印）会极大地影响结构的孔隙率，从而控制细胞的黏附，实现材料的生物学固定。本文详细讨论了为骨科应用开发的不同多功能 HAp 复合材料，特别强调了功能梯度材料和抗菌剂的加入。还包括 3D 打印对 HAp 基支架制造的影响，以及对这些支架进行的不同体外和体内研究。此外，本综述不仅通过阐明 4D 打印的最新进展提供了见解和广泛的理解，还为读者指明了 HAp 基复合涂层和支架的设计和应用的未来研究方向。
