Recent advances in hydrogel fabrication approaches and pharmaceutical applications

Hydrogels represent a unique class of three-dimensional crosslinked polymer networks that demonstrate exceptional capacity to absorb and retain water while maintaining structural integrity. Their water-laden composition closely resembles the physicochemical environment of living tissues, making them particularly attractive for biomedical and pharmaceutical research. Over recent decades, a progressive transition has been observed from naturally derived hydrogels toward engineered synthetic variants, owing to improvements in mechanical stability, tunable water retention, and designer functional properties. Synthetic hydrogels can be engineered with precisely controlled architectures, enabling programmable degradation rates and responsive behaviors under physiological conditions. Structurally, hydrogels are classified as two- or multi-component systems, where polymer chain networks form a scaffold with water filling the interstitial voids — a balance governed by the nature and cross link density of the polymer matrix. This review explores the structural basis, physicochemical attributes, classification frameworks, synthesis routes, characterization methods, and emerging biomedical utilities of hydrogels, with emphasis on recent technological breakthroughs.