Engineering smart hydrogels for intelligent drug delivery

Hydrogels are a brand new generation of three-dimensional polymeric networks with crosslinking bonds and the potential to hold large amounts of aqueous solvents and biological fluids, which have attracted considerable interest in numerous fields. Smart hydrogels can show reversible volume phase transitions or sol–gel transitions in response to small environmental stimuli. Stimulus-responsive hydrogels are also known as smart or environment-sensitive hydrogels. Generally, stimuli are categorized into three groups: physical (temperature, strain, light, sound, ultrasound, electric and magnetic fields, and mechanical pressure), chemical (pH, solvent composition, chemical species, or ionic energy), and biological (glucose, enzyme, and antigen) situations and stimuli. Based on this kind of responsiveness, smart hydrogels have performed a great role in a wide variety of applications, including remedy, biomedical engineering, and drug delivery systems. The purpose of this study is to investigate the basic concept of smart hydrogels and categorize them based totally on the types of stimulants in drug delivery systems. This review also discusses the structural elements and functional properties of smart hydrogels, their chemical interactions, and the principle variables involved in their structure. Smart hydrogels have great promise as a futuristic drug delivery system, enabling targeted and managed release of healing agents. Their responsiveness to environmental stimuli opens new avenues for particular and personalized treatments, revolutionizing the pharmaceutical sector.