Royal College of Surgeons in Ireland
Bioinspired Star-Shaped Poly(L-Lysine) Polypeptides.pdf (1.65 MB)

Bioinspired Star-Shaped Poly(L-Lysine) Polypeptides; 2 Efficient Polymeric Nanocarriers for the Delivery of DNA 3 to Mesenchymal Stem Cells

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posted on 2020-03-24, 16:17 authored by David Walsh, Robert MurphyRobert Murphy, Angela Panarella, Rosanne Raftery, Brenton CavanaghBrenton Cavanagh, Jeremy C. Simpson, Fergal O'BrienFergal O'Brien, Andreas HeiseAndreas Heise, Sally-Ann CryanSally-Ann Cryan
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.


Science Foundation 21 Ireland Investigators Program (Grant code 13/IA/1840)

High content screening was facilitated via the Science Foundation Ireland Centre for Research in Medical Device (CURAM), National University of Ireland, Galway and University College Dublin, Ireland (Grant code 13/RC/20173).



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Walsh DP, Murphy RD, Panarella A, Raftery RM, Cavanagh B, Simpson JC, O'Brien FJ, Heise A, Cryan SA. Bioinspired Star-Shaped Poly(l-lysine) Polypeptides: Efficient Polymeric Nanocarriers for the Delivery of DNA to Mesenchymal Stem Cells. Molecular Pharmaceutics.2018;15(5):1878-1891

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