Multi-chamber microcapsule generation for cell culture using a high- and low-volume centrifuge-based droplet shooting device

Fabrication of multi-chamber microcapsules is of great interest in biotechnology, 3D cell culture, microfluidics, and other applications. The centrifuge-based droplet shooting device (CDSD) is a valuable method for multi-chamber microcapsule production, but is limited by loading difficulty and low volumes. We present a new CDSD system that is easy to load for multi-chamber high- or low-volume applications. We describe the structure, characteristics, and principle demonstration of the device. We experimentally determine trends of droplet shape differences and the resulting conditions of glob formation (due to collision with the centrifuge wall) with > 97% accuracy which compares well with published studies. The deformation parameter was shown for the first time relative to centrifugal force at the tip, as well as the angle at droplet splashdown, tip gap, and other features. We showed the formation of dimpled droplets, prolate spheroid, and other shaped microcapsules. A variety of contents were individually addressed into the multi-chamber droplets (cells, fluorescent, and magnetic nanoparticles). Encapsulated cancer (KLE) cells were cultured within alginate hydrogel droplets with > 60% viability for 4 days. Cell release post-encapsulation was demonstrated. Six-compartment droplets were produced from low (2 µL/reservoir) and high (~ 100 µL/reservoir) volumes. We report the highest droplet volume production of any multi-chamber CDSD for small, uniform droplets (7 × 10⁵ droplets; 0.431 g; 106 μm diameter). This newly developed CDSD enables improved placement of nanoparticles or cells within multi-chamber microscale droplets for 3D cell culture and other applications. Graphical abstract: [Figure not available: see fulltext.]