Enhanced localized pressure-mediated non-viral gene delivery.

Topically applied therapies must not only be effective at the molecular level but also efficiently access the target site which can be on milli/centimetre-scales. This bottleneck is particularly inhibitory for peptide and nucleic acid macromolecule drug delivery strategies, especially when aiming to target wounded, infected, and poorly perfused tissues of significant volume and geometry. Methods to drive fluid-flow or to enhance physical distribution of such formulations after local administration in accessible tissues (skin, eye, intestine) would be transformative in realizing the potential of such therapeutics. We previously developed a technology termed Glycosaminoglycan (GAG)-binding enhanced transduction (GET) to efficiently deliver a variety of cargoes intracellularly, using GAG-binding peptides and cell penetrating peptides (CPPs) in the form of nanoparticles. Herein, we demonstrate that the most simplistic GET formulation is relatively poor in diffusing into tissue matrix (tested in collagen scaffolds). Changing nanoparticle physicochemical properties can enhance penetration, however the use of a pressure differential, generating fluid-flow significantly enhances effective gene delivery over milli/centimetre scales. We adapted clinically used pressure systems to administer both negative (Negative pressure (NP) wound therapy; NPWT) and positive pressures (PP; Insufflator). Pressure differences generated enhanced distribution, and we were able to show for the first-time localized gene transfer in vitro in cell scaffolds and enhanced transfection of ex vivo skin explants. The ability to simply control intra-tissue localization of gene delivery on milli/centimetre scales using pressure application will facilitate new drug delivery strategies for accessible tissues. Importantly site-specific enhancement of penetration and activity of novel nanotechnologies and gene therapeutics could be transformative for future regenerative medicine strategies.