Innovative Erythrocyte-based Carriers for Gene Delivery in Porcine Vascular Smooth Muscle Cells: Basis for Local Therapy to Prevent Restenosis

Abstract

Vascular restenosis is affecting 30-40% of patients treated by percutaneous coronary angioplasty (PTCA). The advent of stenting reduced but not abolished restenosis. The introduction of drug eluting stent (DES) further reduced restenosis, but impaired endothelization exposed to intracoronary thrombosis as late adverse event. It is widely accepted that the endothelial denudation and coronary wall damages expose Vascular Smooth Muscle Cells (VSMC) to multiple growth factors and plasma circulating agents thus activating migration and proliferative pathways leading to restenosis. Among the major players of this processes, phosphorylated Elk-1, forming the Elk-1/SRF transcription complex, controls the expression of a different set of genes responsible for cell proliferation. Therefore, it is feasible that gene-specific oligonucleotide therapy targeting VSMC migration and proliferation genes can be a promising therapeutic approach. While a plethora of vehicles is suitably working in static in vitro cultures, methods for in vivo delivery of oligonucleotides are still under investigation. Recently, we have patented a novel erythrocyte-based drug delivery system with high capability to fuse with targeted cells thus improving drug bioavailability at the site of action. Here, the potential of these engineered porcine erythrocytes to deliver a synthetic DNA Elk-1 decoy inside syngenic porcine VSMC was tested. The results of this study indicate that Elk-1 decoy is actually able to inhibit cell proliferation and migration of VSMC. Our data also suggest that erythrocyte-based carriers are more efficient in delivering these oligonucleotides in comparison to conventional vehicles. As a consequence, a lower dose of Elk-1 decoy, delivered by engineered erythrocytes, was sufficient to inhibit cell growth and migration. This approach represents the translational step to reach in vivo experiments in pigs after PTCA and/or stent implantation where oligonucleotide drugs will be site-specific administered by using erythrocyte-based carriers to prevent restenosis.

Clinical and Translational Challenges in Gene Therapy of Cardiovascular Diseases

“…Using "gutless" viral vectors devoid of the immunogenic regions of viral plasmid is an attractive option to reduce the immunologic response, but we have to wait for more in vivo data using these third-generation vectors to reach a conclusive result [160]. Non-viral methods have more barriers to overcome to successfully transfect the cell; however, with the advent of innovative technologies like nanobots [170], stimuli responsive polymers [171], novel erythrocyte based carriers [172], magnetically targeted delivery [173] and focused in vivo plasmid DNA delivery to the vascular wall via intravascular ultrasound destruction of microbubbles [174]; we expect enhanced transgene expression in vascular cells in future studies. This will also be a possible solution to tackle with the immune response associated with the viral vectors.…”

Synthetic blood and blood products for combat casualty care and beyond

“…45 Red blood cells genetically engineered to express an inhibitor of vascular smooth muscle cell proliferation have also been successful in an animal model of coronary graft stenosis. 46 In an animal model, hemoglobin-loaded liposomes have been used to relieve hypoxia in solid tumors, thought to be a means of reducing drug resistance and metastasis. 47 An obvious application is in the treatment of inherited hemoglobinopathies, but for now, this remains experimental.…”

“…As yet, exploration of this concept has been limited to animal models, with encouraging results 45 . Red blood cells genetically engineered to express an inhibitor of vascular smooth muscle cell proliferation have also been successful in an animal model of coronary graft stenosis 46 . In an animal model, hemoglobin-loaded liposomes have been used to relieve hypoxia in solid tumors, thought to be a means of reducing drug resistance and metastasis 47 .…”

Global Initiative for Interdisciplinary Approach to Improve Innovative Clinical Research and Treatment Outcomes in Geriatrics: Biological Cell-Based Targeted Drug Delivery Systems for Geriatrics

“…Finally, the composition of this erythrocyte-based DDS makes it applicable to many clinical settings, such as neoplastic and cardiovascular diseases, pathologies caused by the infection of a human or animal virus, and certain metabolic diseases. [82][83][84][85][86] Erythrocytes loaded with ferromagnetic colloid compound can be magnetically driven at the target organ/tissue by means of an external magnetic field.…”