Injectable Macroporous Cryogels for Minimally Invasive Drug Delivery and Tissue Engineering

Cryogels are a distinct class of polymeric biomaterials synthesized through cryogelation at sub-zero temperatures, resulting in a unique interconnected macroporous architecture. Unlike conventional hydrogels, these scaffolds exhibit exceptional shape-memory properties, mechanical robustness, and rapid swelling kinetics, enabling them to withstand reversible deformation. These attributes facilitate the development of injectable scaffolds that can be delivered via minimally invasive procedures through standard hypodermic needles, subsequently regaining their original geometry in situ. The current state of knowledge regarding the fabrication principles, physicochemical characterization, and biomedical utility of injectable cryogels are discussed in this paper. The cryotropic gelation mechanism, where the critical role of ice crystals as porogens and the non-frozen liquid microphase in defining the scaffold's microstructure are discussed in this review. Cryogels have several important applications including oncology and regenerative medicine