Mesoporous silicon particles as intravascular drug delivery vectors: Fabrication, in-vitro, and in-vivo assessments

Porous silicon is an attractive biomaterial for drug delivery thanks to its biocompatibility, biodegradability, ease of fabrication, tunable nanostructure, and porous network. Herein we briefly present the development of a multi-stage delivery vector that leverages these advantages to enhance delivery of systemically administered therapeutic agents. We illustrate the rational design, objective-oriented fabrication and geometric control of first stage porous silicon microparticles. We describe how geometry affects the biodistribution of first stage vectors and how their porous structure affects the loading and release of second stage theranostic payloads. We describe the mechanism of cellular internalization and intracellular trafficking of particles. Finally we present two multi-stage vector prototypes for the delivery of magnetic resonance imaging contrast agents and small interfering RNA.