Biomaterials with droplet microfluidics

Abstract

Generating biomaterials with controlled structure, morphology and physicochemical properties is a key enabler of modern bioengineering, with applications in areas ranging from tissue engineering to drug delivery. In this context, microgels — hydrogel particles with characteristic dimensions in the micrometre range — have become a foundational, modular and versatile platform for building biomaterials. Their design can be tailored across multiple length scales, integrating a range of scientific and engineering principles. In this Review, we focus on the power of droplet microfluidics to make materials drop by drop, and how this allows us to control and tailor the properties of microgels. We outline the basic principles of droplet microfluidics-enabled microgel fabrication and explore microfluidic strategies for the production of microgels and modulation of their physicochemical properties, extending beyond simple isotropic designs. We then review their applications, distinguishing between single microgels and their assemblies. We highlight how microgel features, such as size, porosity and modularity, enable unique opportunities in analytical chemistry, cell culture and drug delivery applications. Collective assemblies of microgels into jammed scaffolds are also discussed in the context of tissue engineering and biofabrication. Finally, we discuss current limitations in microgel fabrication and characterization, and outline emerging directions for future research in the field. Droplet microfluidics enables the precise fabrication of microgels, which are microscale hydrogel particles that serve as modular building blocks for biomaterials. This Review outlines principles of microfluidic microgel production, strategies for tailoring structure and functionality, and applications spanning drug delivery, cell culture and tissue engineering, while highlighting current challenges and future directions.