Antimicrobial Sponge: A Polyvinyl Alcohol, Tannic Acid and Curcumin-Loaded Nanolignin Hydrogel Composite Scaffold

Materials with antimicrobial properties and high adsorption capabilities are crucial for managing exudate in post-surgical cases. However, achieving both properties simultaneously remains a challenge. In this study, we first synthesized curcumin-loaded organosolv lignin nanoparticles (Lig-Cur Nps) using a solvent-shifting approach in a continuous flow reactor. These Lig-Cur NPs were then dispersed in a polyvinyl alcohol (PVA) solution. The PVA-Lig-Cur NP colloidal suspension was further crosslinked with tannic acid (TA) through hydrogen bonding interactions. A simple freeze-thaw cycle of the PVA-Lig-Cur NP suspension with TA resulted in the formation of a stable gel, which was then lyophilized to fabricate the PVA-Lig-Cur-TA hydrogel scaffold. This scaffold features an interconnected microporous network with a swelling percentage of 800%, enabling the rapid adsorption of exudates. Its excellent properties and antimicrobial efficacy against Staphylococcus aureus, a bacterium commonly found on the skin, and Pseudomonas aeruginosa highlight its potential to effectively remove exudates while preventing bacterial colonization.