Sustained delivery and expression of DNA encapsulated in polymeric nanoparticles

Abstract

Sustained release polymeric gene delivery systems offer increased resistance to nuclease degradation, increased amounts of plasmid DNA (pDNA) uptake, and the possibility of control in dosing and sustained duration of pDNA administration. Furthermore, such a system lacks the inherent problems associated with viral vectors. Biodegradable and biocompatible poly(DL-lactide-co-glycolide) polymer was used to enacapsulate pDNA (alkaline phosphatase, AP, a reporter gene) in submicron size particles. Gene expression mediated by the nanoparticles (NP) was evaluated in vitro and in vivo in comparison to cationic-liposome delivery. Nano size range (600 nm) pDNA-loaded in poly(DL-lactideco-glycolide) polymer particles with high encapsulation efficiency (70%) were formulated, exhibiting sustained

Poly (D, L-lactide-co-glycolide)/DNA microspheres to facilitate prolonged transgene expression in airway epithelium in vitro, ex vivo and in vivo

“…Nebulization of pharmacological agents encapsulated in PLG has been described, particularly for airway delivery of antituberculous therapy, 23 but the effect of nebulization on PLG-encapsulated plasmid DNA has not yet been studied. While encapsulation of the DNA potentially offers a way to both protect DNA from degradation 15 and also control its release, 7 analysis of DNA extracted from our microspheres, as well as in previous studies, 6 revealed a relative increase in the amount of nicked DNA compared to supercoiled. Whether this translates into loss of transfection efficiency remains unclear.…”

“…To determine the amount and structural integrity of pDNA incorporated during preparation of the PLG microspheres, pDNA was extracted from the microspheres using a method previously described. 6 Briefly, the microspheres (10 mg) were dissolved in chloroform (1.5 ml) and the pDNA extracted by serial ( Â 5) additions of TE buffer (0.5 ml each time). pDNA content was analysed by spectrophotometry (Unicam UV1, ThermoSpectronic, Cambridge, UK) at 260 nm.…”

“…DNA has also been formulated with the synthetic, biodegradable polymer, poly(lactide-co-glycolide) (PLG) to generate microparticles capable of sustained gene delivery and expression. [5][6][7] PLG, which has a history of safe application in humans, 8 has been used extensively in the development of vaccine technology, [9][10][11] and may be loaded with biologically active molecules of widely different molecular size including insulin, 12 prolidase, 13 camptothesin 14 and rhVEGF. 15 pDNA encapsulated in PLG remains stable, and protected from enzymatic degradation.…”

Calcium carbonate nanoparticle delivering vascular endothelial growth factor-C siRNA effectively inhibits lymphangiogenesis and growth of gastric cancer in vivo

“…In addition, the divalent metal cation Ca 2 þ could form ionic complexes with the nucleic acid backbone and may stabilize DNA structures, so the CaCO 3 nanoparticle-DNA complexes can effectively cross cell membranes by ion channel-mediated endocytosis. 39 Because of the dissolution of calcium carbonate in the low acidic medium of endosomal compartments, the calcium carbonate nanoparticles are dissolved in the endosome and destabilize it through osmotic imbalance, and finally deliver the genetic material out into the cytosol. 40 The electrostatic interaction of Ca 2 þ with negatively charged DNA makes the DNA stable against nuclease attack, so that DNA can slowly enter the nucleus without any degradation.…”

Inhibitory efficacy of hypoxia-inducible factor 1α short hairpin RNA plasmid DNA-loaded poly (D, L-lactide-co-glycolide) nanoparticles on choroidal neovascularization in a laser-induced rat model

“…38,69 The encapsulation of pDNA within microspheres or NPs has also been shown to preserve their in vivo functional integrity when the contact time with lysosomal enzymes is shortened. 37,70,71 Prior research that followed the kinetics of tissue and cellular localization of NPs loaded with either Rh-6G or Nile red also showed that the injected NPs reach the retina rapidly, homing in on the RPE cells where they were still observed 4 months after the injection; encapsulated Rh-6G dye diffused slowly from the NPs and uniformly stained the retinal layers. 72 RPE cells, as main constituents in CNV, are known to quickly respond and adapt to environmental stresses such as ischemia and metabolic changes by expressing a number of various genes, 73 and have a major role in CNV because of their essential function in neural retina homeostasis.…”