Chitosan coatings on titanium-based implants - From development to characterization and behavior: A systematic review

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Chitosan is a natural polymer with inherent antibacterial and bone-healing properties, making it suitable for implant coatings.
• A knowledge gap exists regarding the correlation between the physical-chemical characteristics of chitosan coatings and their biological performance on titanium implants.
• Titanium implants are widely used in orthopedics and dentistry, necessitating improved surface modifications for enhanced osseointegration and infection prevention.

Purpose of the Study:

• To systematically review and synthesize the existing literature on the relationship between the physical and chemical properties of chitosan coatings on titanium implants and their antibacterial activity and osteoblast viability.
• To identify key material characteristics and fabrication methods influencing the performance of chitosan-based coatings for orthopedic and dental applications.
• To address the gap in understanding how chitosan coating properties translate to biological outcomes in vitro.

Main Methods:

• A systematic literature search was conducted across four databases and grey literature, adhering to PRISMA guidelines, with no restrictions on publication date or language.
• Two independent reviewers performed a blinded selection of eligible studies evaluating in vitro physical, chemical, microbiological, and biological properties of chitosan coatings on titanium.
• Included studies underwent risk of bias assessment using a specific tool, with a focus on fabrication techniques, material characterization (FT-IR, thickness, adhesion, roughness, wettability), antibacterial assays, and osteoblast viability tests.

Main Results:

• Ten studies met the inclusion criteria, all demonstrating a low risk of bias.
• Chitosan coatings exhibited effective antibacterial activity and cytocompatibility on titanium implant surfaces.
• The efficacy of chitosan coatings was found to be dependent on the specific materials incorporated into the coating and the fabrication techniques employed.

Conclusions:

• Polymeric chitosan coatings on titanium implants demonstrate significant potential for enhancing antibacterial properties and promoting osteoblast viability.
• The physical and chemical characteristics, influenced by fabrication methods and incorporated materials, are critical determinants of chitosan coating performance.
• Further time-dependent in vitro studies are recommended to optimize chitosan coating manufacturing processes, potentially leading to increased market availability and patent opportunities.