Influence of Soybean Oil Blending with Polylactic Acid (PLA) Films: In Vitro and In Vivo Evaluation

Due to the great interest in oil-based polymers, which are prepared from renewable resources, different forms and amounts of soybean oil-based PLA films were prepared and evaluated for their potential usage as a medical biomaterial. Soybean oil, epoxidized soybean oil and auto-oxidized soybean oil were blended with PLA and PLA/oil films with appropriate oil amounts [2, 7, 14 and 20% (w/w)] were obtained by solvent casting. Thermal stability and plasticization effect were determined by adjusting oil amounts and type. Epoxidized soybean oil blended films showed the smallest increase in elongation breaks (13–20%) and the highest decrease in thermal decomposition temperatures (364–327 °C) compared to other oil blended films. In vitro quantitative and qualitative cytotoxicity results showed no reactivity (grade 0) for the L929 cells treated with 14% (w/w) oil blended PLA films. In vivo irritation and implantation tests concluded that 14% (w/w) oil blended PLA films were non-irritant. No erythema, no oedema reactions, no traumatic necrosis and foreign debris were observed. Thus, along with superior biocompatibility, PLA/oil films can replace petroleum-based products for several biomedical uses.