Visible-light-responsive reduced graphene oxide/g-C3N4/TiO2 composite nanocoating for photoelectric stimulation of neuronal and osteoblastic differentiation

Ziru Yan; Kai Li; Dandan Shao; Qingyi Shen; Yi Ding; Shansong Huang; Youtao Xie; Xuebin Zheng

doi:10.1039/d2ra00282e

Visible-light-responsive reduced graphene oxide/g-C₃N₄/TiO₂ composite nanocoating for photoelectric stimulation of neuronal and osteoblastic differentiation

RSC Adv. 2022 Mar 22;12(15):8878-8888. doi: 10.1039/d2ra00282e. eCollection 2022 Mar 21.

Authors

Ziru Yan^{1

2}, Kai Li^{1

2}, Dandan Shao^{1

2}, Qingyi Shen³, Yi Ding¹, Shansong Huang¹, Youtao Xie^{1

2}, Xuebin Zheng^{1

2}

Affiliations

¹ Key Laboratory of Inorganic Coating Materials CAS, Shanghai Institute of Ceramics, Chinese Academy of Sciences Shanghai China likai@mail.sic.ac.cn xbzheng@mail.sic.ac.cn.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences Beijing China.
³ Department of Stomatology, Huashan Hospital, Fudan University Shanghai China.

Abstract

Restoration of nerve supply in newly formed bone is critical for bone defect repair. However, nerve regeneration is often overlooked when designing bone repair biomaterials. In this study, employing graphitic carbon nitride (g-C₃N₄) as a visible-light-driven photocatalyst and reduced graphene oxide (rGO) as a conductive interface, an rGO/g-C₃N₄/TiO₂ (rGO/CN/TO) ternary nanocoating with photoelectric conversion ability was fabricated on a Ti-based orthopedic implant for photoelectric stimulation of both bone and nerve repair. Compared with g-C₃N₄/TiO₂ (CN/TO) and TiO₂ nanocoatings, the ternary nanocoating exhibited stronger visible-light absorption as well as higher transient photocurrent density and open circuit potential under blue LED exposure. The improved photo-electrochemical properties of the ternary nanocoating were attributed to the enhanced separation of photogenerated carriers at the heterointerface. For the tested nanocoatings, introducing blue LED light irradiation enhanced MC3T3-E1 osteoblastic differentiation and neurite outgrowth of PC12 cells. Among them, the rGO/CN/TO nanocoating exerted the greatest enhancement. In a coculture system, PC12 cells on the ternary nanocoating released a higher amount of neurotransmitter calcitonin gene-related peptide (CGRP) under light irradiation, which in turn significantly enhanced osteoblastic differentiation. The results may provide a prospective approach for targeting nerve regeneration to stimulate osteogenesis when designing bone repair biomaterials.