title: Tumor targeting RGD conjugated bio-reducible polymer for VEGF siRNA expressing plasmid delivery.
abstract: Targeted delivery of therapeutic genes to the tumor site is critical for successful and safe cancer gene therapy. The arginine grafted bio-reducible poly (cystamine bisacrylamide-diaminohexane, CBA-DAH) polymer (ABP) conjugated poly (amido amine) (PAMAM), PAM-ABP (PA) was designed previously as an efficient gene delivery carrier. To achieve high efficacy in cancer selective delivery, we developed the tumor targeting bio-reducible polymer, PA-PEG1k-RGD, by conjugating cyclic RGDfC (RGD) peptides, which bind αvβ3/5 integrins, to the PAM-ABP using polyethylene glycol (PEG, 1 kDa) as a spacer. Physical characterization showed nanocomplex formation with bio-reducible properties between PA-PEG1k-RGD and plasmid DNA (pDNA). In transfection assays, PA-PEG1k-RGD showed significantly higher transfection efficiency in comparison with PAM-ABP or PA-PEG1k-RAD in αvβ3/5 positive MCF7 breast cancer and PANC-1 pancreatic cancer cells. The targeting ability of PA-PEG1k-RGD was further established using a competition assay. To confirm the therapeutic effect, the VEGF siRNA expressing plasmid was constructed and then delivered into cancer cells using PA-PEG1k-RGD. PA-PEG1k-RGD showed 20-59% higher cellular uptake rate into MCF7 and PANC-1 than that of non-targeted polymers. In addition, MCF7 and PANC-1 cancer cells transfected with PA-PEG1k-RGD/pshVEGF complexes had significantly decreased VEGF gene expression (51-71%) and cancer cell viability (35-43%) compared with control. These results demonstrate that a tumor targeting bio-reducible polymer with an anti-angiogenic therapeutic gene could be used for efficient and safe cancer gene therapy.
authors.affiliation: Center for Controlled Chemical Delivery (CCCD), Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Hyun Ah
authors.initials: HA
authors.lastname: Kim
authors.affiliation: Center for Controlled Chemical Delivery (CCCD), Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA.
authors.forename: Kihoon
authors.initials: K
authors.lastname: Nam
authors.affiliation: Center for Controlled Chemical Delivery (CCCD), Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT 84112, USA; Department of Bioengineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791, South Korea. Electronic address: sw.kim@pharm.utah.edu.
authors.forename: Sung Wan
authors.initials: SW
authors.lastname: Kim
mesh_terms: D002460:Cell Line; D045744:Cell Line, Tumor; D018014:Gene Transfer Techniques; D006801:Humans; D009369:Neoplasms / Q000235:genetics / Q000628:therapy; D009842:Oligopeptides / Q000737:chemistry*; D010084:Oxidation-Reduction; D010957:Plasmids / Q000008:administration & dosage* / Q000235:genetics; D011108:Polymers / Q000737:chemistry*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
chemical_list: D009842:Oligopeptides; D011108:Polymers; D034741:RNA, Small Interfering; D042461:Vascular Endothelial Growth Factor A; C047981:arginyl-glycyl-aspartic acid
keywords: Bio-reducible polymer; Cancer gene therapy; RGD peptides; Targeted gene delivery; VEGF siRNA