In Vitro Study of Degradation and Cytocompatibility of Ceramics/PLA Composite Coating on Pure Zinc for Orthopedic Application

Shenghui Su; Qiangqiang Tang; Dongbin Qu

doi:10.3389/fbioe.2022.856986

In Vitro Study of Degradation and Cytocompatibility of Ceramics/PLA Composite Coating on Pure Zinc for Orthopedic Application

Front Bioeng Biotechnol. 2022 Mar 4:10:856986. doi: 10.3389/fbioe.2022.856986. eCollection 2022.

Authors

Shenghui Su¹, Qiangqiang Tang², Dongbin Qu^{1

3}

Affiliations

¹ Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, Southern Medical University, Guangzhou, China.
² School of Materials Science and Engineering, South China University of Technology, Guangzhou, China.
³ Department of Orthopaedic Surgery, Zengcheng Branch of Nanfang Hospital, Southern Medical University, Guangzhou, China.

Abstract

Zinc and its alloys are considered to be next-generation materials for fabricating absorbable biomedical devices. However, cytotoxicity has been reported to be associated with rapid degradation. To address these issues, a composite coating (PLA/Li-OCP) consisting of CaHPO₄ conversion coating (Ca-P) and polylactic acid (PLA) decorated with Li-octacalcium phosphate particles was constructed on pure zinc. The immersion tests showed that the presence of Ca-P coating and PLA/Li-OCP coating on pure zinc could reduce the pH value. Compared with Ca-P coating, the introduction of the PLA/Li-OCP film on the Ca-P-coated samples could enhance the corrosion resistance, and there was one order of magnitude decrease in the corrosion current density. The cytocompatibility assay suggested that the PLA/Li-OCP coating favored the cell viability and upregulated the expression of related osteogenic-genes including RUNX2, OCN, and BMP. Therefore, the presence of the PLA/Li-OCP coating on pure zinc could effectively improve the degradation rate and cytocompatibility of pure zinc.

Keywords: PLA film; biodegradation behavior; cytocompatibility; pH; zinc.