Nanocapsules with excellent biocompatibility and stability in protein solutions.

Silica nanocapsules (SiONCs) are usually prepared with cationic surfactants that are not cytocompatible. Dialysis can be used to remove surfactants but leads to instability of the SiONCs when they are in the presence of proteins or biological media. Herein, SiONCs stabilized with a reactive surfactant are synthesized to prevent leaching upon dialysis. The SiONCs show superior stability and biocompatibility compared with SiONCs prepared with conventional surfactants. The SiONCs can be used in self-healing materials, smart agriculture and biomedical applications.