(473g) Engineering Lipid Nanoparticles for Drug Delivery to Alleviate Oxidative Stress during Stem Cell Transplant Therapy

The success of stem cell therapy is dependent on the survival of stem cells against oxidative stress and inflammation. Due to shear stress during injection, reactive oxygen species (ROS) are produced resulting in apoptosis and release of inflammatory mediators. Vitamin E has been well known for its anti-oxidant properties and thus can be used as a drug in this study. In this study, we will describe the engineering of clinically translatable lipid based nanoparticles (LNPs) encapsulated with Vitamin E to protect iPS cells target against hydrogen peroxide induced oxidative stress. LNPs were characterized by both photon correlation spectroscopy to determine particle size distribution, hydrodynamic diameter, and polydispersity, and by zeta potential measurements to determine nanoparticle surface charge characteristics and to quantify colloidal stability. The encapsulation studies were performed using the standard curve for absorbance measurement of vitamin E at 295 nm wavelength and we achieved about 75 % encapsulation efficiency. The preliminary uptake studies using stem cells and FITC tagged LNPs indicated that the nanocarriers were internalized into the cytosol. The oxidative stress was induced by treating iPS cells with 100 μM H₂O₂ with or without LNP encapsulated Vitamin E. The viability of iPS cells was enhanced after LNP-vitamin E treatment. In addition, ROS production was observed after vitamin E treatment. The vitamin E loaded LNPs targeted to these cells showed a significant decrease in the reactive oxidative stress induced due to peroxide. On further performing MTT assay, it showed that cells treated with vitamin E loaded particles had significantly higher viability than control groups just treated with peroxide. We are currently measuring gene expression analysis of vitamin E-treated iPS cells associated with oxidative stress and apoptosis, including NOS2, Casp3, p53, BAX, NF-kappa B, and HIF1α genes. The findings of this study may help in developing effective stem cell therapy for the diseases characterized by the oxidative stress and inflammation.