Design and characterization of Zn-integrated cellulose nanoparticle derived from sugarcane bagasse for biomedical applications.

The valorization of agricultural residues for synthesizing advanced nanomaterials has garnered significant attention in recent years. This study reports the environmentally benign and cost-effective extraction of cellulose from sugarcane bagasse (SCB), a prevalent agro-industrial byproduct for the synthesis of nanoparticles integrated with Zn (CNP-Zn). Cellulose was extracted from SCB through iterative alkali treatment and bleaching, followed by in situ zinc incorporation during nanoparticle formation via acid hydrolysis and physicochemically characterized. Dynamic Light Scattering (DLS) analysis indicated an average particle diameter of 341.52 nm (PDI 0.4786), whereas Field Emission Scanning Electron Microscopy (FESEM) and High-Resolution Transmission Electron Microscopy (HR-TEM) images demonstrated quasi-spherical morphology (< 100 nm). The Fourier Transform Infrared Spectroscopy (FTIR) confirmed the presence of characteristic cellulose functional groups. X-ray Diffraction (XRD) patterns revealed a crystalline structure. Antioxidant activity, assessed via the DPPH assay, demonstrated CNP-Zn's free radical scavenging capacity. Hemolytic analysis (10-500 µg/ml) showed less than 2% red blood cell lysis, supporting the cytocompatibility of CNP-Zn. These nanoparticles exhibited moderate anticancer activity compared to their control (IC50 557.61 µg/ml) in the triple-negative breast cancer cell line MDA-MB-231. Apart from this, bio-stimulant and favourable biocompatibility have been monitored in plant assays (250-2500 µg/ml) on Vigna radiata. These nanoparticles also revealed moderate broad-spectrum UV protection with a Sun Protection Factor (SPF) of 13.54; CNP-Zn represents its good UV-protecting feature. These studies thus highlight the ability of agricultural waste-derived CNP-Zn as a sustainable nanomaterial for biomedical applications.