Microscale hydrogels with dimensions of
or
less are powerful tools for various biomedical applications such as tissue engineering,
drug delivery, and biosensors, due to their size, biocompatibility, and their
controllable biological, chemical, and mechanical properties. In this review, we
provide a broad overview of the approaches used to synthesize and characterize
microgels, as well as their applications. We discuss the various methods used to
fabricate microgels, such as emulsification, micromolding, microfluidics, and
photolithography. Furthermore, we discuss the effects of porosity and crosslinking
density on the mechanical and biological properties of hydrogels. In addition, we give
specific examples of the use of hydrogels, such as scaffolds and cell encapsulation for
tissue engineering, controlled release materials for drug delivery, and environmentally
sensitive sensors for microdevices. Finally, we will discuss the future applications of
this technology.