Yuan Xun, Zhu Wei, Yang Zhongyuan, Chen Feng, Han Xiaoxiao
National Engineering Research Center for High-Efficiency Grinding, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China.
Bioengineering (Basel). 2023 Feb 28;10(3):307. doi: 10.3390/bioengineering10030307.
Poly-L-lactic acid (PLLA) has gained great popularity with researchers in regenerative medicine owing to its superior biocompatibility and biodegradability, although its inadequate bioactivity inhibits the further use of PLLA in the field of bone regeneration. Zinc oxide (ZnO) has been utilized to improve the biological performance of biopolymers because of its renowned osteogenic activity. However, ZnO nanoparticles tend to agglomerate in the polymer matrix due to high surface energy, which would lead to the burst release of the Zn ion and, thus, cytotoxicity. In this study, to address this problem, carbon-ZnO (C-ZnO) was first synthesized through the carbonization of ZIF-8. Then, C-ZnO was introduced to PLLA powder before it was manufactured as scaffolds (PLLA/C-ZnO) by a selective laser sintering 3D printing technique. The results showed that the PLLA/C-ZnO scaffold was able to continuously release Zn ions in a reasonable range, which can be attributed to the interaction of Zn-N bonding and the shielding action of the PLLA scaffold. The controlled release of Zn ions from the scaffold further facilitated cell adhesion and proliferation and improved the osteogenic differentiation ability at the same time. In addition, C-ZnO endowed the scaffold with favorable photodynamic antibacterial ability, which was manifested by an efficient antibacterial rate of over 95%.
聚左旋乳酸（PLLA）因其卓越的生物相容性和生物降解性而在再生医学领域受到研究人员的广泛关注，尽管其生物活性不足限制了PLLA在骨再生领域的进一步应用。氧化锌（ZnO）因其著名的成骨活性而被用于改善生物聚合物的生物学性能。然而，由于高表面能，ZnO纳米颗粒倾向于在聚合物基质中团聚，这会导致锌离子的突发释放，从而产生细胞毒性。在本研究中，为了解决这个问题，首先通过ZIF-8的碳化合成了碳-氧化锌（C-ZnO）。然后，在通过选择性激光烧结3D打印技术将PLLA粉末制成支架（PLLA/C-ZnO）之前，将C-ZnO引入其中。结果表明，PLLA/C-ZnO支架能够在合理范围内持续释放锌离子，这可归因于Zn-N键相互作用和PLLA支架的屏蔽作用。支架中锌离子的控释进一步促进了细胞黏附和增殖，同时提高了成骨分化能力。此外，C-ZnO赋予支架良好的光动力抗菌能力，其抗菌率高达95%以上。
