Guo Ying, Tran Richard T, Xie Denghui, Wang Yuchen, Nguyen Dianna Y, Gerhard Ethan, Guo Jinshan, Tang Jiajun, Zhang Zhongming, Bai Xiaochun, Yang Jian
Department of Orthopedic, Academy of Orthopedics, Guangdong Province, The Third Affiliated Hospital, Southern Medical University, Guangzhou, 510280, China; Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, 510515, China.
J Biomed Mater Res A. 2015 Feb;103(2):772-81. doi: 10.1002/jbm.a.35228. Epub 2014 May 29.
Attempts to replicate native tissue architecture have led to the design of biomimetic scaffolds focused on improving functionality. In this study, biomimetic citrate-based poly (octanediol citrate)-click-hydroxyapatite (POC-Click-HA) scaffolds were developed to simultaneously replicate the compositional and architectural properties of native bone tissue while providing immediate structural support for large segmental defects following implantation. Biphasic scaffolds were fabricated with 70% internal phase porosity and various external phase porosities (between 5 and 50%) to mimic the bimodal distribution of cancellous and cortical bone, respectively. Biphasic POC-Click-HA scaffolds displayed compressive strengths up to 37.45 ± 3.83 MPa, which could be controlled through the external phase porosity. The biphasic scaffolds were also evaluated in vivo for the repair of 10-mm long segmental radial defects in rabbits and compared to scaffolds of uniform porosity as well as autologous bone grafts after 5, 10, and 15 weeks of implantation. The results showed that all POC-Click-HA scaffolds exhibited good biocompatibility and extensive osteointegration with host bone tissue. Biphasic scaffolds significantly enhanced new bone formation with higher bone densities in the initial stages after implantation. Biomechanical and histomorphometric analysis supported a similar outcome with biphasic scaffolds providing increased compression strength, interfacial bone ingrowth, and periosteal remodeling in early time points, but were comparable to all experimental groups after 15 weeks. These results confirm the ability of biphasic scaffold architectures to restore bone tissue and physiological functions in the early stages of recovery, and the potential of citrate-based biomaterials in orthopedic applications.
对复制天然组织结构的尝试已促使人们设计出专注于改善功能的仿生支架。在本研究中，开发了基于柠檬酸的仿生聚（柠檬酸辛二醇酯）-点击-羟基磷灰石（POC-点击-HA）支架，以同时复制天然骨组织的组成和结构特性，同时为植入后大段骨缺损提供即时结构支撑。制备了具有70%内相孔隙率和各种外相孔隙率（5%至50%之间）的双相支架，分别模拟松质骨和皮质骨的双峰分布。双相POC-点击-HA支架的抗压强度高达37.45±3.83MPa，可通过外相孔隙率进行控制。还对双相支架进行了体内评估，用于修复兔10mm长的桡骨节段性缺损，并与植入5、10和15周后的均匀孔隙率支架以及自体骨移植进行比较。结果表明，所有POC-点击-HA支架均表现出良好的生物相容性，并与宿主骨组织广泛骨整合。双相支架在植入后的初始阶段显著增强了新骨形成，骨密度更高。生物力学和组织形态计量学分析支持了类似的结果，双相支架在早期提供了更高的抗压强度、界面骨长入和骨膜重塑，但在15周后与所有实验组相当。这些结果证实了双相支架结构在恢复早期恢复骨组织和生理功能的能力，以及基于柠檬酸的生物材料在骨科应用中的潜力。
