Morphological and biological properties of silica nanoparticles for CRTC3-siRNA delivery and downregulation of the RGS2 expression in preadipocytes.

The aim of this study was to characterize the morphological properties of amorphous silica nanoparticles (SiO NPs), their cytotoxicity and intracellular location within Human Osteoblasts (HOB). Additionally, SiO NPs were explored for their effectivity as carriers of CRTC3-siRNA on Human Preadipocytes (HPAd), and thus downregulate RGS2 gene expression. SiO NPs were synthesized using the method of Stöber at 45 °C, 56 °C, and 62 °C. These were characterized via TEM with EDS, Zeta Potential and FT-IR. Cytotoxicity was evaluated by XTT at three concentrations 50, 100 and 500 µg/mL; SiO NPs intracellular localization was observed through Confocal Laser Scanning Microscope. Delivering siRNA effectivity was measured by RT-qPCR. Morphology of SiO NPs was spherical with a range size from 64 to 119 nm; their surface charge was negative. Confocal images demonstrated that SiO NPs were located within cellular cytoplasm. At a SiO NPs concentration of 500 µg/mL HOB viability decreased, while at 50 µg/mL and 100 µg/mL cell viability was not affected regardless SiO NPs size. SiO NPs-CRTC3-siRNA are effective to down-regulate RGS2 gene expression in HPAd without cytotoxic effects. The developed SiO NPs-CRTC3-siRNA are a promising tool as a delivery vehicle to control obesity.