Green valorization of cannabis wastes into CNC/AgNP nanohybrids for controlled silver ion release in antibacterial hydrogels

The rapid expansion of cannabis cultivation has led to a substantial accumulation of agricultural waste, particularly stems and leaves, posing environmental challenges. In this study, the cannabis wastes were valorized into nanomaterials. Cellulose nanocrystals (CNC) were extracted from cannabis stems via KMnO 4 /oxalic acid oxidation, yielding rod-shaped particles with 19 nm in diameter and 196 nm in length. Cannabis leaf extract exhibited strong reducing capability for the synthesis of silver nanoparticles (AgNPs). CNC served as a substrate for AgNPs to form nanohybrids. UV–Vis spectroscopy and TEM confirmed the formation of AgNPs with a diameter of 16 nm, while the CNC/AgNP retained a comparable dimension. XPS confirmed the presence of metallic silver (Ag⁰) in the nanohybrids, while XRD revealed no significant alteration in the crystalline structure after incorporation. Nanohybrids were incorporated into polyvinyl alcohol/chitosan hydrogels, enhancing mechanical strength and conferring antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus at 0.5 wt% loading. AgNP hydrogels showed rapid Ag + release within 6 h, while CNC/AgNP enabled a two-stage, sustained release. Kinetic modeling indicated Fickian diffusion for AgNP films and non-Fickian transport for nanohybrids. Cytotoxicity tests of the nanohybrid hydrogels demonstrated an acceptable viability rate in HDFa. These findings position CNC/AgNP nanohybrids as sustainable materials offering controlled Ag + release, antibacterial efficacy, and biocompatibility for advanced biomedical systems. • CNCs were successfully extracted from cannabis stems using a green oxidation method. • Biosynthesis of AgNPs on the surface of CNC was achieved using cannabis leaf extract. • Hydrogel with 0.5 wt% CNC/AgNPs inhibited both Gram-positive and Gram-negative bacteria. • CNC/AgNPs enabled a two-stage, sustained Ag⁺ release with improved control. • Hydrogel with 0.5 % CNC/AgNPs exhibited acceptable biocompatibility with HDFa cells.