Smart multifunctional hydrogels with shape memory, conductivity, self-healing, and adhesive properties for biomedical applications

Shape memory hydrogels often suffer from slow recovery, mechanical weakness, and poor stability under physiological environments, limiting their biomedical applicability. Herein, we developed a multifunctional smart hydrogel composed of gelatin, chitosan, alginate, and montmorillonite clay (GCAM), engineered for advanced biomedical applications. The hydrogel exhibited ion-responsive shape memory behavior, through calcium-mediated “egg-box” fixation and bicarbonate-induced recovery, achieving robust recovery of complex geometries. GCAM hydrogels showed a high swelling ratio (324.1 ± 22.4%), an interconnected porous structure, excellent skin adhesiveness without leaving residue, and controlled degradation (14.1 ± 0.3% weight loss by day 20 and 85.4 ± 2.1% by day 60 in PBS). The material exhibited rapid self-healing (≤ 1 h), recovering ∼90% tensile strength and maintaining electrical conductivity to enabling LED illumination in a closed circuit. Enoxaparin was successfully encapsulated and released in a sustained manner over 14 days, with cumulative release of 91.6 ± 5.4%. The hydrogel showed strong biocompatibility with viability exceeding 80% at 80 μg/mL in mouse vascular endothelial cells, alongside excellent hemocompatibility, and the promotion in vascularization in the CAM assay. Collectively, these findings highlight the multifunctional potential of the GCAM hydrogel for advanced biomedical and wearable applications.