Bioinspired Oil Core/Silica Shell Nanocarriers with Tunable and Multimodal Functionalities

The application of multimodal systems in the field of nanomedicine is advantageous as they can perform two or more tasks simultaneously. Here a robust approach is presented mimicking biogenic silica to design a multilayered nanocarrier system with a central oil core encapsulated within a polymer-silica shell. The outermost silica shell has been deposited through a biosilicification process induced by poly-L-lysine molecules immobilized on the surface of emulsion droplets. This system can be simultaneously loaded with high amount of hydrophobic molecules or contrasting agents in the inner oil core, while the polymeric-silica layers can be easily tagged with at least two different contrasting agents. Additionally, the zwitterionic nature of the silica precipitating peptide (poly-L-lysine) has been efficiently exploited to modulate and entirely reverse the surface charge of the nanocarrier without using any additional coating material. It has been demonstrated experimentally that the designed nanocapsular system is monodisperse, nontoxic, cargo protective, tunable in thickness, fluorescent, and magnetic resonance imaging (MRI) active so highly versatile for multiple applications in the field of drug delivery and in vivo imaging.