Nanostructured TPS/PVA/CNC films for sustained copper oxide nanoparticle Release: Toward Advanced transdermal dressing systems

Abstract

The search for biodegradable alternatives to traditional dressings has driven the development of thermoplasticstarch nanocomposite films (T) with polyvinyl alcohol (P) and cellulose nanocrystals (CNC). Films were preparedvia the casting technique with varying PVA concentrations (10, 20, 30, and 40 % w/v) and CNC reinforcements(2.5, 5.0, and 10 % w/w). The synthesis and characterization of copper oxide nanoparticles (NPCuO) was alsocarried out. The best-performing films were further modified with NPCuO to study their controlled release. Thefinal material developed (T/P/10CNC/NPCuO) was extensively characterized, with measurements of thickness,swelling capacity in PBS buffer, tensile test, contact angle measurements, thermogravimetric analysis (TGA) andFourier-transform infrared spectroscopy (FTIR). In addition, solubility, water vapor permeation, NPCuO releaseby visible ultraviolet spectroscopy (UV–Vis) and the cytocompatibility of the developed films were studied.NPCuO characterization showed hexagonal morphologies, a zeta potential of –32 mV, a hydrodynamic diameterof 122 nm (PDI = 0.5). Mechanical tests revealed that adding 10 % CNC tripled the stress at rupture compared tounreinforced films. Contact angle measurements (62◦) confirmed hydrophilicity, a desirable property fordressings. The films showed good solubility in PBS, sustained release of nanoparticles for 8 h. Water vaporpermeability increased from 0.9 to 1.75 g.mm-2.kPa-1.day-1 with CNC addition and to 1.88 g.mm-2.kPa-1.day-1 with NPCuO. NPCuO release was low but provided enhanced antioxidant activity: 76 % (24 h), 67 % (48h), 43 % (72 h), and 38 % (96 h), outperforming T/P/10CNC. These nanocomposites exhibit promising mechanical,permeability, and antioxidant properties, making them suitable candidates for transdermal dressings.