by Dr. Anderson Shum, Mechanical Engineering
Nov 3, 2016
Emulsions, which consist of droplets of one liquid in another immiscible liquid, such as oil droplets in water, are ubiquitously found in everyday products, ranging from salad dressing to paints. However, their use in biomedical application is often limited by the presence of oils, which can degrade the drugs, such as proteins and enzymes, which need to be encapsulated within the droplets. An emerging type of emulsions, often called all-aqueous emulsions, which consist of aqueous droplets in an aqueous solution and are free of any oils, have been demonstrated as a promising alternative for delivering and processing biomolecules and drugs without compromising their efficacy. In this work, Song et al. solve a long-standing challenge of stabilizing the water-in-water droplets by applying protein nanofibrils, which are nanometer-sized fibers of proteins. The protein nanofibrils' slender shape, their preference dissolve in the surrounding aqueous phase as well as their ability to continuously grow impart the superior stability to the resulting all-aqueous emulsion. We also demonstrate the fabrication of a new type of protein microcapsules by connecting the protein nanofibrils that stabilize the droplets. This novel approach of forming stable all-aqueous emulsions holds great potential for biomedical encapsulation of delicate and sensitive drugs and biomolecules.
