GelMA-Based Hydrogels for Controlled Delivery of Antimicrobial Peptides against Candida albicans Biofilm

Abstract Objective: This study aimed to engineer and characterize GelMA hydrogels and dual-cross-linked GelMA–alginate hydrogels as tunable delivery platforms for antimicrobial peptides (AMPs; Histatin-5, GK-17, and INLK), and to evaluate their physicochemical properties, release kinetics, cytocompatibility, and antibiofilm efficacy against Candida albicans. Methods: Hydrogels with varying GelMA concentrations (5%, 7.5%, and 10%), with or without alginate, were fabricated and characterized in terms of microstructure, rheological and mechanical properties, swelling, degradation, and AMP release kinetics. Cytocompatibility was assessed using human gingival fibroblasts, and antimicrobial activity was evaluated through colony-forming unit counts, metabolic activity assays, biomass quantification, and confocal microscopy. Results: All hydrogels exhibited suitable moldability, pseudoplastic behavior, and structural stability. Increasing GelMA concentration and alginate incorporation enhanced mechanical properties: G10 displayed a higher compressive modulus (12,437.39 ± 565.33 Pa; p < 0.0001) compared with the other GelMA-only groups, while G7.5A showed the highest value overall (18,090.45 ± 2324.12 Pa; p < 0.0001). Sustained peptide release was observed over 48 h, with faster release from lower GelMA concentrations; G5 released 20.46% of Histatin-5-FAM after 48 h (p < 0.006). All formulations showed high cytocompatibility, with viability exceeding 100% at 24 h, indicating a stimulatory effect on fibroblast metabolic activity rather than mere absence of cytotoxicity. Hydrogels loaded with INLK or GK-17 significantly reduced C. albicans biofilm viability, biomass, and metabolic activity, whereas unloaded hydrogels showed no antifungal effect. G5-INLK reduced biofilm viability by approximately 1.6 log (p < 0.006) among the GelMA 5% groups, G7.5-INLK and G7.5-GK-17 reduced it by approximately 2 log (p < 0.0001), and G10-INLK produced a 0.9–1.2 log reduction. Conclusion: GelMA-based hydrogels provide a tunable and biocompatible platform for controlled AMP delivery, enabling effective disruption of C. albicans biofilms. This approach represents a promising strategy for the localized treatment of C. albicans-associated oral biofilm infections.