Double emulsion templated monodisperse antibubbles via combined high-shear homogenization and T-junction microfluidics.

Antibubbles are unique bubbles (within a bulk liquid) that comprise liquid core(s). This study focused on creating and evaluating antibubbles with multiple cores using double emulsion (DE) templating. The primary emulsion (PE) was made using high-shear homogenization and then passed through a T-junction to form the DE. These DEs were then freeze-dried and rehydrated to form antibubbles. The study examined the effect of PE parameters (homogenization speed (rpm), internal phase ([Formula: see text], %), and interfacial particle concentration ([Formula: see text], %)), second emulsification parameters (flow rate ratio, interfacial particle concentration ([Formula: see text], %), microchannel size, and additional cryoprotectants in continuous phase), and post-emulsification freezing temperature on DE and the antibubble. The best conditions for yielding small-sized DE and the antibubble with maximum reconstitution coefficient (RC) were selected to evaluate the encapsulation efficiency (EE) of calcein in [Formula: see text]. The study found that antibubbles could provide better EE than DEs for storage longer than 7 days. Future studies should focus on scaling up production, improving EE during the DE-to-antibubble transition, and evaluating stability and release dynamics under in-vitro gastrointestinal simulations using human digestive fluids and tissues for more accurate in vivo predictions.