Supplementary file 1_Effect of tannic acid content on the properties and antibacterial activity of Shapeable polyvinyl alcohol/sodium alginate/tannic acid/borax (PBST) composite hydrogels.docx

In this study, the role of TA concentration (2, 4, and 8 mg/mL) in polyvinyl alcohol/sodium alginate/tannic acid/borax (PBST) composite hydrogels prepared by a one-pot method was systematically investigated. The shapeability, compressive/rheological properties, swelling, degradation, biocompatibility, and antibacterial activity of the composites were evaluated.

Increasing the TA content from 2 to 8 mg/mL raised the compressive modulus from 1.80 to 25.46 kPa, improved rheological performance, and reduced the swelling ratio at 96 h from 67.44% to 29.67% as well as the degradation rate at 21 days from 56.07% to 22.62%, although shapeability decreased at the highest TA level. The hydrogels exhibited favorable in vitro and in vivo biocompatibility. Antibacterial efficacy also increased with TA dosage: the antibacterial rates against Staphylococcus aureus/E. coli were 31.10%/30.01% for PBST0.2, 69.23%/56.75% for PBST0.4, and 79.07%/59.80% for PBST0.8, with the highest TA concentration showing the strongest overall antibacterial effect.