Bioinspired Laponite-Reinforced Gelatin/Alginate Nanocomposite Hydrogels with Tunable Properties for Enhanced Cartilage Tissue Engineering

Abstract Cartilage tissue engineering offers a promising strategy for the regeneration of damaged cartilage, a tissue with limited self-repair capacity. The development of bioengineered scaffolds that closely mimic the mechanical and biological properties of native cartilage is critical to restoring its function. In this study, we fabricated and characterized gelatin/alginate hybrid hydrogels incorporating varying concentrations of laponite nanoclay particles (0, 1, and 2 wt.%) for potential application in cartilage tissue engineering. The microstructural, mechanical, physicochemical, and biological properties of the hydrogel nanocomposites were systematically evaluated using FTIR, XRD, SEM, swelling and degradation analyses, compression testing, rheological measurements, MTT assay, and cell adhesion studies. The incorporation of laponite nanoclay significantly influenced the hydrogel properties, reducing pore size (from 46 ± 9 µm to 26 ± 7 µm), decreasing the swelling ratio (by ~70% and ~50%), and lowering the degradation rate (from 50% to 40% and 2.5% after 6 hours and 21 days, respectively). Additionally, mechanical strength more than doubled, and the hydrogels exhibited shear-thinning behavior. All formulations maintained a high hydration level (>90%), providing a favorable environment for cell viability and proliferation. These findings indicate that laponite nanoclay-reinforced gelatin/alginate hydrogels possess a biomimetic structure, tunable mechanics, controlled biodegradability, and excellent biocompatibility, making them promising candidates for cartilage tissue engineering applications.