pH-Responsive κ-Carrageenan–Egg Albumin Hydrogels Reinforced with Curcumin–Aloe vera Composite for Drug Delivery and Tissue Engineering Applications

Abstract Regeneration of impaired tissues requires advanced biomaterials that integrate mechanical integrity with antioxidant functionality and biocompatibility. In this study, we fabricated a bioactive κ-carrageenan–egg albumin (KC–EA) hydrogel incorporating a curcumin–Aloe vera (CUR–ALV) composite via ionotropic gelation. Incorporation of the CUR–ALV composite enhanced both structural and functional properties of the hydrogel, as characterized through mechanical testing, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and swelling analyses. The composite-loaded hydrogel exhibited enhanced mechanical performance relative to the KC–EA hydrogel, while SEM analysis revealed increased surface roughness and heterogeneous microdomains suggesting successful composite incorporation. The hydrogel exhibited pH-responsive curcumin release, reaching a maximum cumulative release of approximately 80% at pH 8.5, with kinetic modeling suggesting erosion-influenced release under alkaline conditions. The system demonstrated high hydrophilicity and controlled biodegradation under physiological conditions. Antioxidant assessment by the DPPH assay showed substantially enhanced radical scavenging activity (~ 67%), likely reflecting the synergistic contribution of curcumin and Aloe vera constituents. In vitro cytocompatibility assessed by the MTT assay suggested high cell viability comparable to tissue culture polystyrene (TCPS) over seven days, suggesting cytocompatibility and sustained cellular proliferation. Overall, these findings suggest that CUR–ALV-loaded KC–EA hydrogels represent a promising pH-responsive, antioxidant-active system for drug delivery and tissue engineering applications.