Study of the Influence of Structure-Chemical Properties of Electron Beam-Polymerized PEGDA/Gelatin Hybrid Hydrogels on the Uptake and Release Dynamics of Different Photosensitizer Molecules

Hybrid hydrogels are promising for wound dressing, tissue engineering, and drug delivery due to their exceptional biocompatibility and mechanical stability. This study synthesized hybrid hydrogels for photodynamic therapy using electron beam-initiated polymerization with varying PEGDA/gelatin ratios and irradiation doses to evaluate their effectiveness as uptake and release systems for five photosensitizers. Toluidine blue, O (TBO); methylene blue (MB); eosin, Y; indocyanine, green; and sodium meso-tetraphenylporphine-4,4',4″,4‴-tetrasulfonate were studied for their uptake and release dynamics in relation to their structural properties and the hydrogels' composition. Uptake was influenced by the gelatin ratio and ionic properties, with anionic photosensitizers achieving over 80% uptake while cationic ones remained below 45%. Increased irradiation doses highlighted the roles of ionic interactions, hydrophilicity, and surface polarity. Cationic photosensitizers produced singlet oxygen 9-10 times more efficiently. Nontoxic PEGDA/gelatin hydrogels demonstrated photosensitizer-dependent cytotoxicity, with TBO and MB consistent with previous findings. These results confirm their potential in photodynamic therapy.