TiO₂ nanotubes-MoS₂/PDA-LL-37 exhibits efficient anti-bacterial activity and facilitates new bone formation under near-infrared laser irradiation

Abstract

Titanium dioxide (TiO2), as one of the titanium (Ti)-based implants, holds a promise for a variety of anti-bacterial application in medical research. In the current study, a functional molybdenum disulfide (MoS2)/polydopamine (PDA)-LL-37 coating on titanium dioxide (TiO2) implant was prepared. Anodic oxidation and hydrothermal treatment was given to prepare TiO2 nanotubes-MoS2/PDA-LL-37 (T-M/P-L). The in vitro osteogenic effect of T-M/P-L was evaluated by measuring mesenchymal stem cell (MSC) adhesion, proliferation, alkaline phosphatase (ALP) activity, extracellular matrix (ECM) mineralization, collagen secretion and osteoblast-specific messenger RNAs (mRNAs) expression. The determination on the anti-bacterial ability of T-M/P-L was followed. Furthermore, the ability of T-M/P-L to promote bone formation in vivo was evaluated. Near-infrared (NIR) laser irradiation exposure enabled the T-M/P-L coating-endowed Ti substrates to hold effective anti-bacterial ability. T-M/P-L promoted the adhesion and proliferation of MSCs. In addition, an increase was witnessed regarding the ALP activity, collagen secretion and ECM mineralization, along with the expression of runt-related transcription factor 2, ALP and osteocalcin in the presence of T-M/P-L. Additionally, T-M/P-L could stimulate endothelial cells to secrete vascular endothelial growth factor (VEGF) and promote capillary-like tubule formation. Upon NIR laser irradiation exposure, T-M/P-L not only exhibited efficient in vivo anti-bacterial activity but also facilitated new bone formation. Collectively, T-M/P-L had enhanced anti-bacterial and osteogenic activity under NIR laser irradiation.

Regulation of LL-37 in Bone and Periodontium Regeneration

“…Meanwhile this system significantly promotes osteogenesis in both uninfected and infected models [ 109 ]. Jin M et al developed a functional molybdenum disulfide (MoS 2 )/polydopamine (PDA)-LL-37 coating on titanium dioxide (TiO 2 ) implant and found that this LL-37-coated system can promote the adhesion and proliferation of MSCs as well as osteoblast differentiation and function evidenced by the increase in alkaline phosphatase (ALP) activity, collagen secretion, and ECM mineralization, along with the increased expression of osteoblastic marker genes including runt-related transcription factor 2 (RUNX2), ALP, and osteocalcin [ 110 ]. Besides these findings, Cheng Q et al found that LL-37 can promote odontogenesis and osteogenesis from stem cells of the apical papilla (SCAPs).…”

External Stimuli-Responsive Strategies for Surface Modification of Orthopedic Implants: Killing Bacteria and Enhancing Osteogenesis

“…Furthermore, multiple approaches utilizing photothermal-based material modification have been explored. Titanium-based materials have been used extensively due to their exceptional biocompatibility, − as well as other substrates. − Herein, we provide a comprehensive overview of recent advancements in antibacterial and osteogenic strategies based on light responsiveness, as outlined in Table . While NIR I-region lasers (750–900 nm) have been predominantly utilized in the field of orthopedic implants, studies employing NIR II-region lasers (1000–1700 nm) remain relatively scarce.…”