Multifaceted material characterization and biocompatibility evaluation of polylactic acid nanocomposites reinforced with palmyra nanofibrillated cellulose

Abstract

Eco-conscious nanocomposites are developed by embedding nanofillers into biopolymeric matrices, enhancing their properties in various aspects. Polylactic acid (PLA), a naturally degradable thermoplastic derived from renewable resources, is renowned for its sustainable and eco-friendly attributes. However, despite extensive research on PLA-based nanocomposite films, there is a gap in studies exploring PLA reinforced with Palmyra nanofibrillated cellulose (NFC). This study explores the incorporation of Palmyra NFC into PLA using the solution casting method to improve its thermal, mechanical, bactericidal, and biosafety properties. FTIR analysis reveals the formation of hydrogen bonds between the hydroxyl (–OH) moieties of NFC and the carbonyl (C=O) in PLA, which helps the compatibility and dispersion of the components. Thermal analysis shows 27°C increase in thermal degradation temperature compared to plain PLA. The addition of NFC increases the tensile strength and modulus of PLA nanocomposites by 68.8% and 89.4%, respectively. The antibacterial performance improves with higher NFC content, inhibiting bacterial growth more effectively than plain PLA. The hemolysis and MTT assays demonstrate good red blood cell compatibility and high cell viability, confirming the excellent biocompatibility of the 3 wt% NFC reinforced PLA nanocomposite at below 200 µg/mL concentrations. The improvements in thermal stability, mechanical strength, antibacterial properties, and biocompatibility suggest that these nanocomposites can meet the demanding requirements of biomedical materials.