Sustainable castor oil-based adhesives with enhanced adhesive and biocompatible properties for biomedical applications

Castor oil, a renewable plant-based resource, has gained attention as a promising substitute for petroleum in adhesive production. Despite its potential, the development of castor oil-based adhesives (COA) with enhanced adhesive and biocompatible properties remains challenging. This study addresses these challenges by employing a simple one-pot, solvent-free method to synthesize COA, aiming to optimize its adhesive and biological characteristics. Various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and water contact angle measurements, were employed to characterize COA’s chemical structure, thermal properties, and wettability. Additionally, cytotoxicity, and biocompatibility were evaluated through cell viability assays and histological analysis. The results demonstrated that COA adhesives, with a castor oil content exceeding 70 %, exhibited strong adhesive properties (with an initial tack of ball number 13, 180° peel strength of 11.06 N/25 mm, and tack retention of 16.2 h.), improved thermal stability（-15°C to 251°C）, and favorable biocompatibility. Notably, COA displayed minimal cytotoxicity and no significant skin irritation in animal models. Furthermore, COA treatment promoted angiogenesis and supported tissue healing, highlighting its potential in biomedical applications. This study demonstrates that adhesives derived from renewable castor oil provide a sustainable and biocompatible alternative for adhesive applications in both industrial and everyday use, contributing to the development of environmentally friendly materials. • A simple, solvent-free, one-pot synthesis method was developed to produce high-performance adhesives. • Adhesive contains a high content of castor oil component. • Biocompatibility and renewable content align with sustainable development goals. • Versatile adhesive suitable for food packaging, pharmaceuticals, and medical uses