Li Lan, Li Yixuan, Yang Longfei, Yu Fei, Zhang Kaijia, Jin Jing, Shi Jianping, Zhu Liya, Liang Huixin, Wang Xingsong, Jiang Qing
School of Mechanical Engineering, Southeast University, Nanjing 210000, China.
Department of Sports Medicine and Adult Reconstructive Surgery, Drum Tower Hospital affiliated to Medical School of Nanjing University, Nanjing 210000, China.
Ann Transl Med. 2019 Jun;7(11):240. doi: 10.21037/atm.2019.04.79.
Titanium implants are widely used in orthopedic and dental for more than 30 years. Its stable physicochemical properties and mechanical strength are indeed appropriate for implantation. However, the Bioinertia oxidized layer and higher elastic modulus often lead to the early implantation failure.
In this study, we proposed a simple design of porous structure to minimize the disparity between scaffold and natural bone tissue, and introduced a one-step reaction to form a polydopamine (PDA) layer on the surface of titanium for the purpose of improving osteogenesis as well. The porous scaffolds with pore size of 400 µm and porosity of 44.66% were made by additive manufacturing. The cell behavior was tested by seeding MC3T3-E1 cells on Ti6Al4V films for 15 days. The biomechanical properties were then analyzed by finite element (FE) method and the osteogenesis effect was accordingly evaluated by implanting the scaffolds for 5 weeks in rabbits.
According to the achieved results, it was revealed that the immersion for 40 min with dopamine could significantly improve the cell adhesion. The proposed method for design of porous structure can avoid the stress shielding effect and bone growth inside the PDA coating scaffolds, which were observed at the early stage of bone healing process.
It can be concluded that the proposed PDA coating method is effective in promoting early osteogenesis, as well as being easy to operate, and can be helpful in the future clinical application of titanium implants.
钛植入物在骨科和牙科领域已广泛应用30多年。其稳定的物理化学性质和机械强度确实适合植入。然而，生物惰性氧化层和较高的弹性模量常常导致早期植入失败。
在本研究中，我们提出了一种简单的多孔结构设计，以尽量减少支架与天然骨组织之间的差异，并引入一步反应在钛表面形成聚多巴胺（PDA）层，目的也是为了改善骨生成。通过增材制造制备了孔径为400 µm、孔隙率为44.66%的多孔支架。通过将MC3T3-E1细胞接种在Ti6Al4V薄膜上15天来测试细胞行为。然后通过有限元（FE）方法分析生物力学性能，并通过将支架植入兔子体内5周来评估骨生成效果。
根据所得结果，发现用多巴胺浸泡40分钟可显著改善细胞粘附。所提出的多孔结构设计方法可以避免在骨愈合过程早期观察到的PDA涂层支架内的应力屏蔽效应和骨生长。
可以得出结论，所提出的PDA涂层方法在促进早期骨生成方面是有效的，并且易于操作，有助于钛植入物未来的临床应用。
