PVA/CMC/Attapulgite Clay Composite Hydrogel Membranes for Biomedical Applications: Factors Affecting Hydrogel Membranes Crosslinking and Bio-evaluation Tests

Abstract Herein, polyvinyl alcohol-carboxymethyl cellulose (PVA-CMC) composite hydrogel membranes were prepared using solution-casting method, where citric acid (CA) was added as crosslinker in different ratios of (7, 10 and12 wt%). Attapulgite clay extracted from Northwestern Desert of Borg El-Arab, Egypt; was incorporated as nanofiller (1, 2, 4, and 5 wt%) into membranes for improving their mechanical/ thermal stability. Results revealed that, physicochemical properties of membranes e.g. swelling%, tensile strength and morphology of membranes affected significantly by different clay concentrations and citric acid crosslinker. Also, attapulgite clay with concentration 1 (wt%) enhanced mechanical strength of composite membranes, compared to other clay concentrations. Furthermore, protein adsorption %, hydrolytic degradation, hemolysis (%) and antimicrobial activity significantly affected by clay contents and CA concentrations. Four bacterial pathogens e.g. Candida albicans , Escherichia coli , Klebsiella pneumoniae , and Bacillus cereus were used for testing antimicrobial activity of prepared membranes. Results referred to increasing of clay contents led to a high hemolysis %; however, increasing CA concentration significantly reduced hemolysis %. Meanwhile, membranes with low clay contents offered the most effective resistance against tested microbes. These findings are referring to the ability of using PVA-CMC-attapulgite composite membranes crosslinked by CA as good candidate of biomaterials for dermal wound dressings.