Plasma-deposited polymer coatings for improved biocompatibility of titanium implants

The surface modification of titanium implants is essential for improving osteointegration and cellular contact, since untreated surfaces may result in fibrous tissue growth and an elevated risk of infections, hence diminishing implant efficacy. Plasma chemical treatment is an environmentally sustainable technique for applying polymer coatings to various surfaces, enabling meticulous regulation of surface characteristics. The integration of functional groups, including carboxyl and amino groups, enhances hydrophilicity and tissue contact, rendering these coatings particularly advantageous for biomedical applications. This study examines the impact of several plasma chemical treatments on the surface characteristics of titanium implants.

Plasma modification was conducted with the ZP-COVANCE-RFPE-3MP plasma system (13.56 MHz). Three therapy modalities were evaluated, commencing with plasma chemical activation in an Ar/O₂ environment (200 W, 10 minutes). In the initial mode, activated samples were submerged in a 25% collagen solution for one hour. The second approach entailed the deposition of amino groups by cyclopropylamine (C₃H₅NH₂) in a CPA/Ar plasma at 50 W. The third mode introduced carboxyl groups via a gas combination of Ar, CO₂, and C₂H₄ at 150 W. Plasma-deposited polymer films were examined utilizing SEM, EDX, XPS, FTIR, and WCA techniques. The adhesion and proliferation of mesenchymal stem cells were quantitatively assessed through fluorescence microscopy.

Plasma deposition yielded homogenous, well-adhered layers devoid of pinholes or fissures, as evidenced by SEM micrographs. Wettability assessments demonstrated a substantial enhancement, with an approximately 100° decrease in the contact angle in the optimal mode alongside notable stability. The coatings facilitated improved adherence and proliferation of mesenchymal stem cells.

Plasma treatment of titanium implants enhanced surface characteristics and biocompatibility. These findings underscore the promise of plasma-deposited polymer coatings for biomedical applications.

This research was funded by the Russian Science Foundation (№24-79-10121).