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

Abstract

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 (, %), and interfacial particle concentration (, %)), second emulsification parameters (flow rate ratio, interfacial particle concentration (, %), 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. 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.