Multifunctional Nanomaterial-Integrated Hydrogels for Sustained Drug Delivery: From Synthesis and Characterization to Biomedical Application

Hydrogels have emerged as versatile platforms for controlled and sustained drug delivery due to their high biocompatibility, tunable mechanical properties, and ability to mimic the natural extracellular matrix. Incorporating functional nanomaterials into hydrogel networks introduces additional structural and functional complexity, enabling stimuli-responsive release, enhanced bioactivity, and synergistic therapeutic effects. This review provides a comprehensive overview of recent advances in the design, fabrication, and characterization of nanomaterial-integrated hydrogels for biomedical applications. Emphasis is placed on nanoparticle synthesis, functionalization strategies, incorporation into hydrogel matrices, physicochemical characterization, and biological aspects, including cytotoxicity, genotoxicity, antioxidative, and antibacterial effects. Emerging approaches for performance optimization, such as preliminary data-driven strategies and machine learning-based modeling, are also discussed. Special attention is given to smart and stimuli-responsive hydrogels and their potential biomedical applications.