In vitro evaluation of cytotoxicity and release kinetics of green-synthesised Azadirachta indica silver nanoparticles.

Toxicological investigations are essential to guarantee the safety of new compound for medical use prior to any clinical application. The aim of this study was to evaluate the cytotoxicity and elucidate the mechanisms of release kinetics of Azadirachta indica-derived silver nanoparticles (AI-AgNPs) for potential medical applications. A comprehensive in vitro cytotoxicity assessment effect using Chinese Hamster Ovary (CHO-CD36) cells was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. The release kinetics were evaluated by fitting experimental data to various models, including the zero-order, first-order, Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin. This allowed for elucidation of the underlying drug release mechanisms. Both MTT and LDH assays reveal that cell viability was reduced by approximately 80% at a concentration of 100 µg/mL and LDH release increased by 30-50% compared to the untreated group in a concentration-dependent manner. Morphological analysis revealed increased circularity and roundness, along with a decreased aspect ratio, indicating cellular stress or apoptosis. The Peppas-Sahlin model provided the best fit (R(2) > 0.95), suggesting that AI-AgNPs release was governed by a combination of Fickian diffusion and case II relaxations.