Enhancing Titanium Surface Properties with Castor Oil-Based Polyurethane: A Sustainable and Low-Cytotoxicity Approach

Titanium implants are widely used in medical and dental applications due to their excellent mechanical properties, biocompatibility, and corrosion resistance. However, surface modifications are often necessary to enhance osseointegration and improve long-term clinical outcomes. In this context, polymeric coatings have gained prominence as a means of modifying the surface properties of titanium implants. Castor oil-based polyurethane (PU) represents a promising alternative due to its low cytotoxicity, biodegradability, and environmentally friendly synthesis process. This study aims to investigate the physicochemical and biological properties of castor oil-based PU coatings on titanium substrates, assessing their potential as a biomaterial for surface modification of titanium implants.

To produce and evaluate the physicochemical and biological properties of castor oil-based polyurethane (PU) coatings on titanium substrates, we focused on their potential as a biomaterial for surface modification of titanium implants.

PU was synthesized from castor oil and characterized by Fourier transform infrared spectroscopy (FTIR) to confirm the synthesis. Thermal stability was analyzed by thermogravimetric analysis (TGA). Surface morphology was investigated by using scanning electron microscopy (SEM) and atomic force microscopy (AFM), while adhesion of PU to titanium was confirmed by X-ray photoelectron spectroscopy (XPS). Increased surface hydrophilicity, confirmed by contact angle tests, and the successful adhesion of polyurethane functional groups identified by XPS highlight the low cytotoxicity of the material, which was analyzed by in vitro cytotoxicity assays.

FTIR analysis confirmed the successful synthesis of PU. Thermal analysis demonstrated that the material remained stable up to 200 °C, with distinct degradation events beyond this temperature range, while SEM and AFM revealed increased surface roughness and porosity, enhancing cell adhesion and osseointegration potential. Contact angle measurements indicated improved hydrophilicity, and XPS confirmed the strong adhesion of PU to titanium. Cytotoxicity assays showed cell viability above 70%, suggesting no significant cytotoxic effect.

Castor oil-based PU proved to be a viable and environmentally friendly alternative for titanium implant coatings, with promising physicochemical and biological properties. MTT assay results demonstrated no significant cytotoxic effect, suggesting the potential for future in vivo biocompatibility studies.