Castor oil plasticized polylactic acid nanocomposites reinforced with screw pine cellulose nanofibers for tissue engineering scaffolds

Biodegradable polymeric nanocomposites have attracted considerable attention in biomedical applications due to their excellent biocompatibility, tunable mechanical properties and ability to support tissue repair and regeneration. The natural fiber based reinforcements improves sustainability and functional performance without compromising the advantages of biodegradable polymers. In this study, cellulose nanofibers (CNFs) were extracted from screw pine leaves and incorporated into a polylactic acid (PLA) matrix to develop nanocomposite films using solution casting method. Castor oil was added as a natural plasticizer instead of conventional synthetic plasticizers to improve the flexibility and processability of the PLA matrix. The CNFs exhibited nanoscale dimensions with good dispersion, enhancing interfacial interaction within the PLA matrix. FTIR analysis confirmed the presence of functional groups and interactions between CNFs and PLA. SEM analysis revealed uniform morphology of the nanocomposites at lower CNF loadings. Mechanical testing analysis showed improved tensile strength and young’s modulus, although elongation at break decreased due to restricted polymer chain mobility. Chemical degradation studies indicated higher sensitivity in alkaline conditions compared to acidic and aqueous conditions. Biodegradation behaviour improved with CNF incorporation due to increased hydrophilicity and microbial accessibility. Hemolysis studies demonstrated blood compatibility at concentrations below 300 µg/mL. Cytotoxicity test results showed high cell viability indicating that the nanocomposites were non-toxic to PBMC cells. These nanocomposites exhibited good mechanical, biodegradation and biocompatibility properties, making them suitable for tissue engineering applications.