Recent Advances in Hydrogel Drug Delivery Systems: Innovations and Applications

The drug delivery systems of hydrogels presented themselves with a very versatile platform by virtue of their capability for encapsulating therapeutic agents and controlled release. Recent efforts limiting hydrogel-based drug delivery aim at developing systems more responsive toward a change in external stimuli like pH, temperature, or light for targeted and on-demand drug release. Recent advances in polymer chemistry have fabricated hydrogels with improved biocompatibility, mechanical strength, and degradation profiles, thereby yielding a wide range of biomedical applications. Moreover, the combination of nanotechnology with hydrogels has rendered new opportunities not only for drugs but also for the delivery of complex drugs such as proteins, peptides, and nucleic acids, which are difficult to administer by traditional drug delivery methods. These novel systems are being explored also for localized and sustained drug delivery, especially in cancer therapy and wound healing, and in tissue engineering. The flexibility of the hydrogels for different routes of administration, namely, injectable formulations and implantable devices, underlines further their potential for application as next-generation drug delivery vehicles. More ongoing research is done in optimizing the drug loading efficiency, release kinetics, and targeting capabilities of the hydrogel system, while increasing therapeutic outcomes and limiting side effects. This review reflects recent trends within hydrogel-based drug delivery but focuses on the role in personalized medicine.