Silica microcarriers produced from a microfluidics-generated emulsion

Abstract

Fabrication of micrometric and submicrometric capsules capable of carrying bioactive substances is important for many biological applications. Here we show the results of our work on creating water-in-oil emulsion and encasing the water droplets in silica shell with microfluidic techniques. The emulsion was generated in a polydimethylsiloxane (PDMS) flow-focusing microfluidic chip. TWEEN 80 and lecithin were used as surfactants to stabilize the emulsion. Tetraethylorthosilicate (TEOS) and 3-aminopropyl trimethoxysilane (APTMOS) were then added to the emulsion to form silica shell around water droplets via hydrolysis. We obtained silica microcapsules of about 2 μm in diameter and studied them using confocal fluorescent microscopy. This method allows encapsulating a wide range of sensitive substances including genetic material, enzymes, proteins for intracellular delivery and other biomedical applications.