Heat shock responsive drug delivery system based on mesoporous silica nanoparticles coated with temperature sensitive gatekeeper.

Mesoporous silica nanoparticles (MSN) have several advantages as carriers for drug delivery, including high drug loading capacity, good biocompatibility, excellent stability, and easily tailorable surface properties. This study describes the design of an MSN-based carrier for use in a heat shock responsive drug delivery system. MSN were functionalized with the temperature-sensitive PEG/PCL multiblock copolymer, as gatekeepers, allowing the release of entrapped drugs in response to heat shock stimuli (MBC-MSN). In the absence of heat shock, doxorubicin (Dox)-loaded MBC-MSN showed very low cytotoxicity, as PEG/PCL inhibited the premature release of Dox from MBC-MSN. In response to heat-shock stimuli, however, these Dox@MBC-MSN showed significant cytotoxicity, similar to that of free Dox. Dox release was due to the loosening of the structure of the gatekeeper, PEG/PCL, in response to the heat shock stimuli. Taken together, these findings suggest that MBC-MSN are a strong candidate to act as a carrier in heat shock responsive drug delivery. [ABSTRACT FROM AUTHOR]