The development of biologically relevant and human-mimicking platforms underlines the appropriate study of novel technologies for human diseases. Previously, animal and 2D models have been used as standard model systems to understand the toxicity of different drugs. The lack of physiological relevance of these systems has given rise to more adequate models such as organoids, and spheroids. These "mini-organs" [1] are expected to have the same complexity as human organs [2]. They have been effectively used in a variety of tissue engineering subfields for cancer predictions and drug development [3]. However, the majority of these systems are built through manual pipetting and liquid handling [2] which leads to a lack of uniformity of the droplets. In this work, a droplet microfluidics approach is implemented to combat the heterogeneity of these non-engineered systems. We demonstrated the tunability of the size of the 3D droplets and the successful encapsulation of 3T3 cells inside the droplets. Due to its versatility, the developed platform can be used for various biomedical applications such as cancer drug toxicity assessment
