PLA/TIO₂ NANOCOMPOSITES: PREPARATION, CHARACTERIZATION, ANTIBACTERIAL AND CYTOTOXICITY EVALUATION FOR FOOD PACKAGING

Abstract

Poly (lactic acid) (PLA) is a polymer with promise for various applications, including food packaging and engineering composites. However, PLA is not appropriate for several applications due to its comparatively weak mechanical and thermal properties. The mechanical and thermal properties of PLA can be enhanced by combining it with other materials. The current study has two objectives: first, to synthesize and characterize PLA/titanium dioxide (TiO₂) nanocomposites using a solvent-casting method. The second objective of the present work was to evaluate the biomedical properties of the modified composites using antibacterial and cytotoxicity studies. The methodology part of the present study includes preparing five samples with different PLA:TiO₂ ratios and characterizing them using a field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX), and dynamic mechanical analysis (DMA). The biomedical properties were evaluated using antibacterial activity against Streptococcus pyogenes (S. pyogenes) and Salmonella. Moreover, cytotoxicity of the prepared samples was evaluated using the MTT assay. The results show that the surface morphology of the PLA/TiO₂ nanocomposites was observed in FESEM as a homogeneous dispersion of TiO₂ nanoparticles in a PLA matrix. Moreover, particle size was measured from SEM images, and the prepared samples showed an average particle size of 27 to 63 nm. The storage modulus of the composites augmented with increasing filler loading, whilst the glass transition temperature decreased from 61.7 to 59.6 °C. The prepared composites showed a significant effect against Streptococcus pyogenes and Salmonella. Moreover, the cytotoxicity test showed higher cell viability against the HEK293 cell lines. The amalgamation of PLA and TiO₂ nanofiller has significant promise for food packaging applications.