Laser-induced surface texturing and nanomaterial functionalization of PLA/PHBV surfaces for enhanced cell adhesion

Abstract

Abstract Current research on the development of biomaterials aims at reducing bacterial colonization and increasing cell adhesion on the surface of implantable devices for regenerative medicine. Equally noteworthy is the growing interest in using materials from renewable sources and biodegradable in medical devices. In this study, femtosecond laser surface texturing was applied to PLA/PHBV polymer blends nanocomposites with and without cellulose nanocrystals (CNCs) and carbon nanotubes (CNTs) fillings. Micro-pillar structures were developed using a femtosecond laser. The textured samples were characterized by SEM, profilometry, and contact angle measurements. The effect of texturing on cytotoxicity, cell adhesion and proliferation were evaluated by MTT assay and confocal fluorescence microscopy by using L929 fibroblasts cell line. The results showed that laser texturing led to a significant increase in surface roughness and caused the material to change from hydrophilic to hydrophobic behavior, a phenomenon explained by the Wenzel model. The polymers showed higher cell viability and directional growth after laser treatment, especially in the samples containing 0.5–1.5 wt% CNT and up to 5 wt% CNC. However, it was observed that at high concentrations of nanofillers the biocompatibility was compromised, which could be attributed to particle agglomeration and percolation effects. Overall, this study highlights the synergistic role of laser-induced microstructures and functionalization with nanomaterials in modulating the surface properties of biopolymers to promote biocompatibility, offering a promising approach for the development of bioactive surfaces for high-performance implants.