Formulation and evaluation of PVA-based composite hydrogels: physicochemical, leachables, and in vitro immunogenicity...

This study explores the formulation and characterization of poly(vinyl alcohol) (PVA)-based composite hydrogels synthesized through solid-state crosslinking. Comprehensive assessments were conducted on their physicochemical properties, leachables, and immunogenicity. Swelling experiments demonstrated that the incorporation of poly(vinylpyrrolidone) (PVP) enhanced water retention, while chitosan had a minimal effect on swelling behavior. Qualitative analysis of leachables identified water-soluble components, including dehydrated PVA and PVP. Fourier-transform infrared (FTIR) spectroscopy confirmed the formation of ester bonds and indicated increased hydrogen bonding post-crosslinking. Thermal stability was validated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), with decomposition observed at 320-330 °C. X-ray diffraction (XRD) analysis revealed enhanced crystallinity following crosslinking. Solid-state nuclear magnetic resonance (NMR) further confirmed chemical changes consistent with the results from other characterization techniques. In vitro assays using DC2.4 mouse dendritic cells showed that hydrogel extracts inhibited cell proliferation without causing cytotoxicity or triggering significant immune responses. These findings highlight the hydrogels' biocompatibility and stability, supporting their potential for biomedical applications.