Fabrication of SnO₂/porous silica/polyethyleneimine nanoparticles for pH-responsive drug delivery

Highlights

• SnO₂/porous silica/polyethyleneimine (SnO₂/PS/PEI) nanoparticles were prepared by emulsion–condensation route.

• The SnO₂/PS/PEI nanoparticles have large specific surface area and high drug storage capacity.

• The SnO₂/PS/PEI nanoparticles display pH-responsive release and aspirin-dependent fluorescence.

Abstract

To create novel nanocarriers for achieving excellent drug delivery performance, pH-responsive fluorescent porous silica (PS) nanocarriers were developed by encapsulating SnO₂ nanoparticles and coating polyethyleneimine (PEI) layer. SnO₂/porous silica (SnO₂/PS) nanoparticles have an average diameter of 80 nm and center-radial large pore channels. The large channels endow them high surface area with a Brunauer–Emmett–Teller (BET) area of 939 m² g^− 1. Aspirin was used as test drug to evaluate the releasing behavior of SnO₂/porous silica/polyethyleneimine (SnO₂/PS/PEI) nanoparticles. Results indicated that aspirin can be successfully incorporated into the SnO₂/PS/PEI nanoparticles and the SnO₂/PS/PEI nanoparticles displayed excellent pH-responsive release. The release rate in pH 7.4 buffer is higher than that in pH 5.5 buffer, which attributed to the PEI structure change in varied pH buffer. In addition, the SnO₂/PS/PEI nanoparticles presented novel drug-dependent fluorescence, which could be used to trace the drug release.