Supramolecular microgels/microgel scaffolds for tissue repair and regeneration

Biomedical microgels are a novel type of materials with promising perspectives for repair and regeneration of multi-types of tissues and organs due to their highly hydrated nature, tunable microporous structure, ability to encapsulate bioactive factors, and tailorable properties such as stiffness and composition. In particular, the reversible bonding in supramolecular microgels leads to their ease of injectability and self-healing ability, which are essential for therapeutic delivery of cells and drugs, assembly to generate scaffolds, and bioinks for 3D printing. In vivo studies of microgels have pioneered the clinical relevance of these novel and innovative materials for regenerative medicine. In this review, the important supramolecular interactions such as hydrogen bonding, ionic bonding, and host-guest and hydrophobic interactions, and metal coordination are summarized with respect to the formation of supramolecular microgels for biomedical applications, highlighting their advantages over the traditional bulk ones. The applications of supramolecular microgels in the fields of cardiac tissue repair, osteoarthritis therapy, and bone and neuronal tissue engineering are discussed.