Mimosa pudica-derived zinc oxide nanoparticles preserve mesenchymal stromal cell viability, morphology, and osteogenic competence

IntroductionMusculoskeletal disorders remain a major cause of disability worldwide and require non invasive regenerative strategies that support tissue repair. Green-synthesized zinc oxide nanoparticles (ZnONPs) have attracted interest because of their biocompatibility and biological activity. This study investigated the synthesis of Mimosa pudica-derived ZnONPs (ZnOMP) and evaluated their effects on human bone marrow mesenchymal stromal cells (BM-MSCs). MethodologyZnOMP were synthesized using an aqueous extract of Mimosa pudica leaves and characterized by UV-Vis spectroscopy, FTIR spectroscopy, powder X-ray diffraction, SEM, EDS, and TEM. BM-MSCs isolated from human bone marrow were exposed to ZnOMP, plant extract, and synthesized ZnO nanoparticles. Cell metabolic activity was assessed by MTT assay after 1, 3, and 5 days. Cytoskeletal and nuclear morphology were analyzed by fluorescence microscopy and CellProfiler-based morphometry. Osteogenic differentiation was evaluated after 21 days using Alizarin Red S staining and quantification. ResultsSpectroscopic and microscopic analyses confirmed the successful formation of phytochemical-capped ZnOMP nanoparticles with nanoscale dimensions and specific elemental composition. ZnOMP maintained significantly higher metabolic activity than Mimosa pudica extract or ZnO at both 150 and 300 g/mL. Morphometric profiling revealed that Mimosa pudica extract induced the most pronounced changes in nuclear morphology, reflecting enhanced nuclear plasticity and substantial remodeling of nuclear architecture, whereas ZnOMP preserved cellular and nuclear features closer to untreated controls. During osteogenic induction, ZnOMP did not impair matrix mineralization and preserved the ability of BM-MSCs to form a mineralized extracellular matrix. ConclusionMimosa pudica-mediated ZnO nanoparticles combine favorable biocompatibility with preservation of mesenchymal stem cell morphology and osteogenic competence. These findings support their potential use as bioactive nanomaterials for musculoskeletal tissue engineering and regenerative medicine.