Delivery of plasmid DNA to vascular tissue in vivo using catheter balloons coated with polyelectrolyte multilayers

Abstract

We report an approach for the localized delivery of plasmid DNA to vascular tissue from the surfaces of inflatable embolectomy catheter balloons. Using a layer-by-layer approach, ultrathin multilayered polyelectrolyte films were fabricated on embolectomy catheter balloons by alternately adsorbing layers of a hydrolytically degradable poly(β-amino ester) and plasmid DNA. Fluorescence microscopy revealed that the films coated the surfaces of the balloons uniformly. Coated balloons that were incubated in phosphate-buffered saline at 37 °C released ~25 μg DNA/ cm 2 over 24 hours. Analysis of the DNA by gel electrophoresis showed that the DNA was released in open-circular ('nicked') and supercoiled conformations, and in vitro cell transfection assays confirmed that the released DNA was transcriptionally active. Arterial injury was induced in the internal carotid arteries of Sprague-Dawley rats using uncoated balloons, followed by treatment with film-coated balloons for 20 minutes. X-gal, immunohistochemical, and immunofluorescence staining of sectioned arteries indicated high levels of β-galactosidase or enhanced green fluorescent protein (EGFP) expression in arteries treated with film-coated balloons. β-galactosidase and EGFP expression were observed throughout the medial layers of arterial tissue, and around approximately two-thirds of the circumference of the treated arteries. The layer-by-layer approach reported here provides a general platform for the balloon-mediated delivery of DNA to vascular tissue. Our results suggest the potential of this approach to deliver therapeutically relevant DNA to prevent complications such as intimal hyperplasia that arise after vascular interventions.

Characterization of Degradable Polyelectrolyte Multilayers Fabricated Using DNA and a Fluorescently-Labeled Poly(β-amino ester): Shedding Light on the Role of the Cationic Polymer in Promoting Surface-Mediated Gene Delivery

“…directly into the structure of a film (i.e., as a `layer'). While incorporated small molecules can be released from PEMs by simple diffusion, 37–40,42,43 films fabricated from larger biomacromolecular species can be designed to erode or disassemble 44 using a broad range of natural or synthetic polyelectrolytes that contain hydrolytically, 22,35,45–50 reductively, 31,32,51–54 or enzymatically degradable bonds. 24,28,55–60 Finally, in the context of DNA delivery considered here, we note that the inherent juxtaposition and commingling of DNA with cationic polymers create opportunities to release DNA as part of an aggregate or electrostatic complex that could promote the internalization and processing of DNA more effectively.…”

“…22,26,35,46,50,62–65 Polymer 1 is a hydrolytically degradable poly(β-amino ester) (PBAE), 15,66 and can be used to fabricate thin films (~100 nm thick) that (i) promote the gradual release of DNA from the surfaces of film coated objects, 26,46 and (ii) promote surface-mediated cell transfection when placed in contact with cells and tissues in vitro 22,26 and in vivo . 34,35 Several of these past studies have used films fabricated using fluorescently labeled plasmid DNA constructs to characterize the release and/or transfer of DNA from film-coated surfaces.…”

“…34,35 Several of these past studies have used films fabricated using fluorescently labeled plasmid DNA constructs to characterize the release and/or transfer of DNA from film-coated surfaces. 22,35,50,64,67 Unfortunately, a more complete understanding of the locations and behaviors of polymer 1 in these past studies has been limited by the lack of fluorescently labeled derivatives of this cationic polymer (and, more generally, by difficulties associated with characterizing the locations and dynamics of unlabeled polymer 1 using other methods of analysis). This current investigation sought to characterize the erosion, release, and intracellular trafficking both of DNA and polymer 1 using PEMs fabricated with two new fluorescently end-labeled derivatives of polymer 1 (polymer 1 TMR and polymer 1 OG ).…”

Hydrophobe-substituted bPEI derivatives: boosting transfection on primary vascular cells

“…Altogether, the superior gene expression profiles combined with the lower cytotoxicity with respect to the gold standard 25 kDa bPEI make PEI2-PrA1 a very promising candidate for the transfection of VSMCs. These transfection results are extremely important because they were obtained in the presence of serum and upon centrifugation of the polyplexes over the cells, mimicking the high concentration at the cell surface that could be found in cardiovascular devices such as gene-eluting stents [35] or catheter balloons [36,37].…”

Reduction of intimal hyperplasia in injured rat arteries promoted by catheter balloons coated with polyelectrolyte multilayers that contain plasmid DNA encoding PKCδ

“…to provide control over SMC and progenitor cell proliferation, migration, and differentiation [17, 20–22]. The work reported here takes a step toward a minimally-invasive, gene-based approach to preventing intimal hyperplasia by using polymer-coated catheter balloons to transfer a potential therapeutic DNA construct to injured vascular tissue [23]. Our approach is based on materials-based methods developed for the stepwise, ‘layer-by-layer’ assembly of nanostructured, polyelectrolyte-based thin films and coatings [24, 25].…”