Enhancement of Cell Adhesion on 3D-Printed PLA through Surface Modification Using Photoactivated Chlorine Dioxide

Poly(lactic acid) (PLA) has attracted considerable attention as a scaffold material in tissue engineering because of its biocompatibility, biodegradability, and suitable mechanical strength. However, PLA's inherent hydrophobicity limits its cell affinity. To address this limitation, several surface modification strategies have been developed; nevertheless, challenges remain, including reduced mechanical strength, limited applicability to three-dimensional structures, and procedural complexity. In response, a surface modification method, termed "photo-oxidation", was developed. This method utilizes reactive species generated by light irradiation of chlorine dioxide radicals and overcomes the aforementioned challenges. In this study, PLA was oxidized using the photo-oxidation method, and its cell affinity was evaluated using mouse fibroblasts (L929 cells). The results showed that photo-oxidation at an appropriate temperature significantly enhanced cell affinity, as evidenced by increased cell numbers and pronounced actin extension. Furthermore, this method was successfully applied to three-dimensional structures, demonstrating its potential as a versatile strategy for improving the biological performance of PLA.