title: Uptake characteristics of NGR-coupled stealth PEI/pDNA nanoparticles loaded with PLGA-PEG-PLGA tri-block copolymer for targeted delivery to human monocyte-derived dendritic cells.
abstract: We have investigated the in vitro uptake, toxicity, phenotypic consequences and transfection efficiency of a stealth NGR/PEG/PDBA-coupled-SHA-PEI/pDNA targeting polyplex loaded with PLGA-PEG-PLGA tri-block copolymer in human monocyte-derived dendritic cells (DCs). Modification with PEG effectively shielded and reduced non-specific phagocytosis by immature DCs to approximately 20%. Coupling the NGR cell-specific peptide to the PEGylated polyplex (NGR/PEG/PDBA-SHA-PEI/pDNA) however resulted in specific and enhanced phagocytosis in DCs without any observable toxicity at the optimum concentration of 0.25% of the copolymer. DNase treatment had no effect on DNA integrity in the encapsulated polyplex. Confocal microscopy confirmed intracellular localization of the targeting NGR/PEG/PDBA-SHA-PEI/pDNA microparticles, resulting in more enhanced uptake of the radiolabeled plasmid DNA and approximately 5- and 10-fold increase over the control tri-block Pluronic F68 copolymer and the non-targeting polyplex, respectively. More importantly, phagocytosis of the targeting microparticles neither altered the functionality of immature DCs nor the phenotypic expression of DC-specific cell surface molecules, CD80, CD86, CD40 and CD54 (ICAM-1), suggesting that uptake of the targeting microparticles by themselves did not induce DC maturation. Taken together, these results suggest that PLGA-PEG-PLGA encapsulation of this stealth targeting polyplex has no negative effects on key properties of immature DCs and should pave the way for targeting DCs for vaccination purposes.
authors.affiliation: Department of Genitourinary Medical Oncology, Laboratory of Experimental Therapeutics, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA. stanley-moffat@excite.com
authors.forename: Stanley
authors.initials: S
authors.lastname: Moffatt
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cristiano
mesh_terms: D002470:Cell Survival; D004247:DNA / Q000008:administration & dosage*; D003713:Dendritic Cells / Q000378:metabolism*; D006801:Humans; D007097:Imines / Q000008:administration & dosage*; D049329:Nanostructures; D009842:Oligopeptides / Q000008:administration & dosage*; D010587:Phagocytosis; D011092:Polyethylene Glycols / Q000008:administration & dosage*; D011095:Polyethylenes / Q000008:administration & dosage*; D011098:Polyglactin 910 / Q000008:administration & dosage*; D011993:Recombinant Fusion Proteins; D014162:Transfection / Q000379:methods*; D014409:Tumor Necrosis Factor-alpha
chemical_list: D007097:Imines; D009842:Oligopeptides; D011095:Polyethylenes; D011993:Recombinant Fusion Proteins; D014409:Tumor Necrosis Factor-alpha; C505405:poly(ethylene imine); C102418:poly(lactic-glycolic acid)-poly(ethyleneglycol) copolymer; C464840:tumor Necrosis Factor-alpha, CNGRC fusion protein, mouse; C464839:tumor necrosis factor-alpha, CNGRC fusion protein, human; D011098:Polyglactin 910; D011092:Polyethylene Glycols; D004247:DNA