Mesoporous Silica Nanoparticles with Large Pores for the Encapsulation and Release of Proteins

Mesoporous silica nanoparticles (MSNs) have been explored extensively as solid supports for proteins in biological and medical applications. Small ( 5 nm), capable of encapsulating therapeutic small molecules suitable for delivery applications in vivo, are rare however. Here we present small, elongated, cuboidal, MSNs with average dimensions of 90 × 43 nm that possess disk-shaped cavities, stacked on top of each other, which run parallel to the short axis of the particle. Amine functionalization was achieved by modifying the MSN surface with 3-aminopropyltriethoxysilane or 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane (AP-MSNs and AEP-MSNs) and were shown to have similar dimensions to the nonfunctionalized MSNs. The dimensions of these particles, and their large surface areas as measured by nitrogen adsorption–desorption isotherms, make them ideal scaffolds for protein encapsulation and delivery. We therefore investigated the encapsulation and release be...