Infra-red laser pulse increases the expression of heat-inducible molecular cargo delivered via mesoporous silica nanoparticles

INTRODUCTION: The use of nanocarriers for gene transfer into reproductive tissues, gametes, or embryos is gaining increasing capability as a non-invasive research tool for the manipulation and investigation of mechanisms... [ view full abstract ]

INTRODUCTION: The use of nanocarriers for gene transfer into reproductive tissues, gametes, or embryos is gaining increasing capability as a non-invasive research tool for the manipulation and investigation of mechanisms underlying unexplained infertility. A significant limitation of current nanocarrier systems is the lack of controlled delivery to target sites, predominantly due to insufficient temporal and spatial control. Current literature describes several advances in specialized nanoparticles that respond to exogenous stimuli such as temperature and magnetic fields in order to assist controlled cargo release; however, such studies have yet to explore nanoparticle systems with thermo-controlled responsive molecular cargo.

METHODS: A specialized molecular construct, featuring green fluorescent protein, and driven by the human heat-shock protein 70-1 promoter (HSP:GFP), was created as cargo for mesoporous silica nanoparticles (MSNPs). The cargo was electrostatically loaded onto MSNPs, and the MSNPs were delivered into HEK293T cells. Cargo expression following MSNP delivery was assessed with and without infra-red laser stimulus. Laser-treated cells were subjected to a single infra-red laser pulse (400mW, 1480nm) to stimulate a heat-shock response.

RESULTS: MSNPs and infra-red laser treatment were not cytotoxic to HEK293T cells, both respectively and together. HSP:GFP cargo expression from MSNP delivery into HEK293T cells was increased two-fold following laser treatment, compared to delivery without laser treatment (p<0.05).

DISCUSSION: We describe for the first time, the development of a laser-activated MSNP system with intrinsic heat-responsive cargo, capable of enhancing gene expression and providing spatial and temporal control. It is expected that this new approach for controlled and enhanced genetic expression could be applied to allow more refined spatio-temporal control of genetic manipulation for investigations into the pathophysiological mechanisms underlying unexplained mechanisms of infertility.