Assessment of biocompatibility for citric acid crosslinked starch elastomeric films in cell culture applications

Abstract

This study investigates the synthesis of potato starch elastomers reinforced with silicon dioxide (SiO<inf>2</inf>) and citric acid as a crosslinking agent to enhance their mechanical and barrier properties. Surface morphology analysis using optical microscopy revealed that pure potato starch films had uneven surfaces. However, higher SiO<inf>2</inf> concentrations increased roughness, while citric acid crosslinked films displayed smoother surfaces overall. Water vapor transmission rates (WVTR) indicated that native starch films were highly hydrophilic, while SiO<inf>2</inf> incorporation and citric acid crosslinking significantly reduced WVTR of 17% (30% lower than native film), enhancing the barrier properties. Tensile strength testing revealed that citric acid crosslinking increased the tensile strength by 25%, while SiO<inf>2</inf> further reinforced the films but decreased elasticity by 15%. SiO<inf>2</inf> had little impact on degradation rates, while citric acid crosslinking delayed microbial growth, extending film longevity by 20%. Biocompatibility assays using SiHa, HT-29, and HEK 293 cell lines revealed that the films had varying degrees of cell confluency. Films with both SiO<inf>2</inf> and citric acid showed improved confluency (20% higher) compared to films containing only SiO<inf>2</inf>. However, citric acid alone resulted in the highest confluency (95% viability), suggesting its significant role in biocompatibility. This eco-friendly approach demonstrates substantial advancements in film properties, offering potential applications in diverse biomedical industries. © The Author(s) 2025.