Polyvinyl alcohol/corn starch/castor oil hydrogel films, loaded with silver nanoparticles biosynthesized in Mentha piperita leaves' extract

Objectives: Hydrogel films were prepared from Polyvinyl alcohol [PVA], Corn starch [CS], Castor oil [CO] and silver nanoparticles [SNP], biosynthesized in leaves' extract of locally grown Mentha piperita L. (Family, Labiatae) for prospective application as wound dressings. Methods: Both aqueous [AME] and methanolic [MME] extracts of Mentha piperita leaves were used for phytochemical synthesis of SNP, that were later dispersed in hydrogel matrix by simple blending of the constituents (PVA, CS, CO, AME/MME and SNP) and crosslinking with glutaraldehyde. Results: The hydrogel films were flexible and biodegradable. The structure analysis by FTIR suggested hydrogen bonding between the functional groups of PVA, CS and CO in the films. SEM analysis revealed that SNP globules were distributed (10.02% and 12.57%) throughout the hydrogel matrices that were prepared from both AME and MME, respectively. The hydrogel films with MME showed higher thermal stability than those formed from AME due to uniform dispersion of small (size <= 70 nm) and unagglomerated SNP in the former. The hydrogel films can be safely used upto 200 degrees C. The antibacterial studies exhibited that the films inhibited the growth of both S. aureus and P. aeruginosa, as investigated by disc diffusion method. Conclusion: The hydrogel films were prepared through ecofriendly and benign route, devoid of any toxic solvents, diluents, surfactants, stabilizers and can be employed as thermally stable, antibacterial and biodegradable films. The hydrogel films with MME showed better performance than AME films, for prospective application as wound dressings. (C) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.

Automated summary

Hydrogel films were prepared from silver nanoparticles (SNP) synthesized with plant extracts, along with other constituents. The films were flexible, biodegradable, exhibited antibacterial properties, and showed high thermal stability, making them suitable for wound dressings.