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

Abstract

New therapeutic approaches that eliminate or reduce the occurrence of intimal hyperplasia following balloon angioplasty could improve the efficacy of vascular interventions and improve the quality of life of patients suffering from vascular diseases. Here, we report that treatment of arteries using catheter balloons coated with thin polyelectrolyte-based films (‘polyelectrolyte multilayers’, PEMs) can substantially reduce intimal hyperplasia in an in vivo rat model of vascular injury. We used a layer-by-layer (LbL) process to coat the surfaces of inflatable catheter balloons with PEMs composed of nanolayers of a cationic poly(β-amino ester) (polymer 1) and plasmid DNA (pPKCδ) encoding the δ isoform of protein kinase C (PKCδ), a regulator of apoptosis and other cell processes that has been demonstrated to reduce intimal hyperplasia in injured arterial tissue when administered via perfusion using viral vectors. Insertion of balloons coated with polymer 1/pPKCδ multilayers into injured arteries for 20 min resulted in local transfer of DNA and elevated levels of PKCδ expression in the media of treated tissue 3 days after delivery. IFC and IHC analysis revealed these levels of expression to promote downstream cellular processes associated with up-regulation of apoptosis. Analysis of arterial tissue 14 days after treatment revealed polymer 1/pPKCδ-coated balloons to reduce the occurrence of intimal hyperplasia by ~60% compared to balloons coated with films containing empty plasmid vectors. Our results demonstrate the potential therapeutic value of this nanotechnology-based approach to local gene delivery in the clinically important context of balloon-mediated vascular interventions. These PEM-based methods could also prove useful for other in vivo applications that require short-term, surface-mediated transfer of plasmid DNA.

Polyelectrolyte Multilayers Promote Stent-Mediated Delivery of DNA to Vascular Tissue

“…The high levels of circumferential gene expression observed in our past studies on balloon-transfer in rats likely resulted from the fact that, in those experiments, film-coated balloons were expanded and left in direct contact with injured tissue for 20 minutes. 46,47 In contrast, the balloons used in stent-mediated experiments in this current study were inflated for only 15–20 seconds prior to deflation and removal. In addition, we note that the arterial tissue of rats is significantly thinner than that of pigs, and the tissue treated in those past experiments was balloon-injured prior to experiment.…”

“…In addition, we note that the arterial tissue of rats is significantly thinner than that of pigs, and the tissue treated in those past experiments was balloon-injured prior to experiment. 46,47 In a broader context, we note that layer-by-layer assembly is also very well suited for coating the surfaces of expanded stents 34 that could subsequently be crimped onto bare balloon assemblies after fabrication. This approach, while technically straightforward, was not adopted here to minimize potential influences that crimping procedures could have on the structures or behaviors of the films used in these proof-of-concept experiments.…”

“…39 In a more general context, several past studies have exploited this layer-by-layer approach to design PEMs relevant to the treatment of cardiovascular diseases and conditions. 32,34,40–47 …”

Engineering Layer‐by‐Layer Thin Films for Multiscale and Multidrug Delivery Applications

“…The capability of controlled nucleic acid delivery has also been demonstrated in biomedical devices such as stents [89,90], and there are many additional areas where localized release will be of interest, including the control of fibrotic disorders and inflammatory or autoimmune response to implanted organs. We have already shown the potential of this kind of approach in the delivery of siRNA directly to tissue in a localized manner as a means of addressing tissue engineering or wound healing, and in the implementation of siRNA in targeted nanoparticles and DNA for transdermal vaccines.…”

The possible pathology and pharmaceutical therapy of ovarian cancer

“…Following TCDD treatment, protein kinase C-delta (PKCδ) is activated in ovarian surface epithelial cancer cells, suggesting a potential intracellular role for PKCδ as an effector molecule for TCDD-mediated biological events in this ovarian cancer (46). PKCδ and its downstream target have been identified as critical factors mediating vascular injury response, such as intimal hyperplasia and aneurysm (47)(48)(49)(50)(51). Ren and colleagues reported that activated PKCδ increases production of pro-inflammatory chemokines through cytosolic interaction with the NF-κB subunit p65 (50).…”