PVA/CMC/Attapulgite clay composite hydrogel membranes for biomedical applications: Factors affecting 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.

Preparation of Food Grade Superhydrophobic Coatings Based on Attapulgite Nanorods

“…APT has received extensive attention in various fields, such as agriculture, 27 environmental protection, 28 cosmetics, 29 textile printing and dyeing, 30 food, 31 and medicine. 32 We have successfully prepared some superhydrophobic or superamphiphobic coatings with a good performance by constructing micro-/nanostructures using APT instead of synthetic nanomaterials. 33−35 However, these coatings aim at applications in oil/water separation, anti-icing, and anticorrosion and are not applicable to the food industry.…”