%0 Journal Article %A Walsh, David %A Murphy, Robert %A Panarella, Angela %A Raftery, Rosanne %A Cavanagh, Brenton %A Simpson, Jeremy C. %A O'Brien, Fergal %A Heise, Andreas %A Cryan, Sally-Ann %D 2020 %T Bioinspired Star-Shaped Poly(L-Lysine) Polypeptides; 2 Efficient Polymeric Nanocarriers for the Delivery of DNA 3 to Mesenchymal Stem Cells %U https://repository.rcsi.com/articles/journal_contribution/Bioinspired_Star-Shaped_Poly_L-Lysine_Polypeptides_2_Efficient_Polymeric_Nanocarriers_for_the_Delivery_of_DNA_3_to_Mesenchymal_Stem_Cells/12018528 %R 10.25419/rcsi.12018528.v1 %2 https://repository.rcsi.com/ndownloader/files/22082925 %K cellular uptake %K gene delivery %K high content screening %K mesenchymal stem cells %K nanomedicine %K star polymer %K tissue engineering %K Pharmaceutical Sciences %X The field of tissue engineering is increasingly recognizing that gene therapy can be employed for modulating in vivo cellular response thereby guiding tissue regeneration. However, the field lacks a versatile and biocompatible gene delivery platform capable of efficiently delivering transgenes to mesenchymal stem cells (MSCs), a cell type often refractory to transfection. Herein, we describe the extensive and systematic exploration of three architectural variations of star-shaped poly(l-lysine) polypeptide (star-PLL) with varying number and length of poly(l-lysine) arms as potential nonviral gene delivery vectors for MSCs. We demonstrate that star-PLL vectors are capable of self-assembling with pDNA to form stable, cationic nanomedicines. Utilizing high content screening, live cell imaging, and mechanistic uptake studies we confirm the intracellular delivery of pDNA by star-PLLs to MSCs is a rapid process, which likely proceeds via a clathrin-independent mechanism. We identify a star-PLL composition with 64 poly(l-lysine) arms and five l-lysine subunits per arm as a particularly efficient vector that is capable of delivering both reporter genes and the therapeutic transgenes bone morphogenetic protein-2 and vascular endothelial growth factor to MSCs. This composition facilitated a 1000-fold increase in transgene expression in MSCs compared to its linear analogue, linear poly(l-lysine). Furthermore, it demonstrated comparable transgene expression to the widely used vector polyethylenimine using a lower pDNA dose with significantly less cytotoxicity. Overall, this study illustrates the ability of the star-PLL vectors to facilitate efficient, nontoxic nucleic acid delivery to MSCs thereby functioning as an innovative nanomedicine platform for tissue engineering applications. %I Royal College of Surgeons in Ireland