Multifunctional PVP/PEG Hydrogel Coatings Functionalized with Taxifolin for Surface Modification of Titanium-Based Substrates

Surface functionalization of metallic implants is widely explored to enhance their performance and functionality. In this study, multifunctional hydrogel coatings based on poly(vinylpyrrolidone) and polyethylene glycol were developed and functionalized with a taxifolin (TAX) inclusion complex and collagen to introduce bioactive features. TAX, a naturally occurring flavonoid with antioxidant and anti-inflammatory properties, was incorporated using β-cyclodextrin to improve its stability and enable controlled release. The coatings were applied to titanium-hydroxyapatite composites and titanium sheet substrates to evaluate their applicability across surfaces with varying morphologies, ranging from porous to relatively smooth. The ceramic phase was modified with magnesium ions to enhance its bioactivity and better mimic the composition of natural bone tissue. FTIR and SEM analyses confirmed hydrogel formation and effective surface coverage. Degradation and incubation studies in simulated physiological environments demonstrated the material’s stability, while UV–Vis analysis indicated TAX release, highlighting the system’s potential as a carrier for flavonoid-based compounds. Indirect cytotoxicity studies using MC3T3-E1 preosteoblasts indicated low cytotoxicity and a favorable biological response of collagen- and taxifolin-modified systems. The developed coatings represent a versatile platform for surface modification of titanium-based biomaterials and demonstrate potential for application across substrates with diverse surface characteristics. Further studies are required to assess their biological potential.