Surface defect engineered-Mg-based implants enable the dual functions of superhydrophobic and synergetic photothermal/chemodynamic therapy

Dongdong Zhang; Ru Xu; Shuhan Chen; Huihui Du; Shi Qian; Feng Peng; Xuanyong Liu

doi:10.1016/j.bioactmat.2023.07.012

Surface defect engineered-Mg-based implants enable the dual functions of superhydrophobic and synergetic photothermal/chemodynamic therapy

Bioact Mater. 2023 Jul 24:30:15-28. doi: 10.1016/j.bioactmat.2023.07.012. eCollection 2023 Dec.

Authors

Dongdong Zhang^{1

2

3

4}, Ru Xu¹, Shuhan Chen^{1

2}, Huihui Du^{1

2}, Shi Qian^{1

2}, Feng Peng^{5

6}, Xuanyong Liu^{1

2

7}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma, The University of Hong Kong Shenzhen Hospital, Shenzhen, China.
⁴ Center for Human Tissues and Organs Degeneration, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen, 518055, PR China.
⁵ Medical Research Institute, Department of Orthopedics, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, 510080, China.
⁶ GuangDong Engineering Technology Research Center of Functional Repair of Bone Defects and Biomaterials, Guangzhou, 510080, China.
⁷ School of Chemistry and Materials Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, 1 Sub-lane Xiangshan, Hangzhou, 310024, China.

Abstract

Promoting metallic magnesium (Mg)-based implants to treat bone diseases in clinics, such as osteosarcoma and bacterial infection, remains a challenging topic. Herein, an iron hydroxide-based composite coating with a two-stage nanosheet-like structure was fabricated on Mg alloy, and this was followed by a thermal reduction treatment to break some of the surface Fe-OH bonds. The coating demonstrated three positive changes in properties due to the defects. First, the removal of -OH made the coating superhydrophobic, and it had self-cleaning and antifouling properties. This is beneficial for keeping the implants clean and for anti-corrosion before implantation into the human body. Furthermore, the superhydrophobicity could be removed by immersing the implant in a 75% ethanol solution, to further facilitate biological action during service. Second, the color of the coating changed from yellow to brown-black, leading to an increase in the light absorption, which resulted in an excellent photothermal effect. Third, the defects increased the Fe²⁺ content in the coating and highly improved peroxidase activity. Thus, the defect coating exhibited synergistic photothermal/chemodynamic therapeutic effects for bacteria and tumors. Moreover, the coating substantially enhanced the anti-corrosion and biocompatibility of the Mg alloys. Therefore, this study offers a novel multi-functional Mg-based implant for osteosarcoma therapy.

Keywords: Anti-bacterial; Anti-tumor; Magnesium-based implants; Superhydrophobic; Surface defects.