Cationic curdlan-based hydrogels loaded with Calendula officinalis-decorated silver nanoparticles: Synthesis,...

Curdlan, known for its biomedical applications, and a quaternary derivative thereof with antimicrobial properties were used to prepare new hydrogels for potential applications in wound dressings. To enhance the antimicrobial and antioxidant properties, silver nanoparticles synthesised in the presence of Calendula officinalis, known for its wound healing activity, were entrapped in the hydrogels. The parameters of the green synthesis of metallic nanoparticles were studied to determine the optimal conditions. Then, the spherical nanoparticles (22 nm) containing biologically active compounds from the plant extract were introduced into the cross-linking process of curdlan and quaternary derivative. The hydrogels exhibited a well-defined porous morphology (60-70 μm) with interconnected pores, which can retain up to 20.34 g/g fluid under skin-simulated conditions. The new hydrogels, with an elastic modulus between 4.85 and 11.31 kPa, exhibit complete and rapid shape recovery after progressive compression of at least five cycles. In addition, they have been shown to be biocompatible in contact with human dermal fibroblasts and can even induce their migration and proliferation within the first 8 h of contact. They have antioxidant properties and antimicrobial activity against S. aureus and E. coli, and the entrapment of silver nanoparticles leads to the augmentation of these properties.