Recent advances in microfluidic 3D cellular scaffolds for drug assays

Microfluidic technologies enable temporal and spatial control of cellular microenvironments by mimicking the complex biological functions of normal cellular interactions, thus opening new opportunities for cell-based drug screening. Microfluidic devices with large-scale integration, automatic operation, and micro-sized scale offer many unique benefits including high throughputs, low cost, and high efficiency in drug development. Here, we review the recent fundamental development of microfluidic three-dimensional (3D) cellular scaffolds and highlight the perspective of drug assay applications in relation to drug screening and nanodrug cytotoxicity analysis. In particular, we discuss the advances in diverse biomimetic strategies including microfabricated 3D cell culture systems, droplet-based 3D hydrogel scaffolds for cell encapsulation, and organs- and tissues-on-chips. A brief summary is also presented along with a perspective of this field in the future.