INSIGHTS INTO THE DEGRADATION OF CARRAGEENAN-BASED HYDROGEL DURING IN-SITU SYNTHESIS OF METAL NANOPARTICLES: PHYSICOCHEMICAL, ANTIBACTERIAL, AND CYTOTOXIC ASSESSMENTS

Metal nanoparticles have emerged as promising materials for wound care. Aiming to minimize the negative impacts of conventional synthesis routes, researchers have focused on green synthesis using polysaccharides and plant extracts [1]. However, few studies are evaluating the effect of the in-situ green synthesis on the polysaccharide structure. Thus, this study assessed the impact of depolymerization caused by the in-situ synthesis of silver (AgNPs) and gold (AuNPs) nanoparticles in kappa-carrageenan (κC) hydrogels. UV-vis spectra and visual inspection confirmed that AgNPs and AuNPs were synthesized using κC as a reducing agent. The samples containing AuNPs synthesized in-situ exhibited a pronounceable reduction in the molecular mass compared to those containing AgNPs. The FTIR spectra confirmed the oxidation and further depolymerization of κC. The κC samples containing AuNPs showed a dose-dependent and lower antibacterial activity than the κC samples containing AgNPs. The cytotoxic results showed that oxidized κC samples are non-toxic against human keratinocyte cells, whereas κC samples containing AuNPs and AgNPs showed dose-dependent toxicity. These findings collectively gave us new insights into the in-situ synthesis of metal nanoparticles by using a green protocol.