Optimization of Nanoparticle Gene Therapy for Stem Cells using Cell Penetrating Peptides

Nova Southeastern University, Davie, Florida, USA

Objective. This study was conducted to determine the optimum gene therapy delivery platform for primary human mesenchymal stem cells (hMSC) using cell penetrating peptide (CPP) coated fluorescent nanoparticle quantum dots (QD). Background. Earlier research has shown that CPP loaded QDs can effectively transfect human cells. This technology allows for the development of transfection platforms for the delivery of gene therapy molecules directly into human cells of interest. hMSCs are primary cells which are notoriously difficult to transfect but which have great therapeutic potential as bioreactor therapeutic cells. The CPP-QD platform can be optimized for gene transfection of hMSC, to achieve this goal. Results. The lower the loading level of targeting CPPs versus control peptides (10% versus 90%) as well as the identity of the targeting peptide (hCT versus CPMLKE) showed differences in cell uptake in hMSCs, as quantified by fluorescent intensity, and also affected the efficacy of therapeutic delivery of the cargo DNA, as quantified by observed expression of the delivered red fluorescent protein gene under fluorescent microscopy. Conclusion. The peptide identity and ratio of loading onto the QD nanoparticle determines the efficacy of therapeutic DNA delivery into hMSCs. Grants. This study was partially funded by a grant from the NSU President’s Faculty Research Development Grant.