Nanoparticle formulation enhances the delivery and activity of a vascular endothelial growth factor antisense oligonucleotide in human retinal pigment epithelial cells.

The objective of this study was to investigate the delivery and activity of a vascular endothelial growth factor (VEGF) antisense oligonucleotide in a human retinal pigment epithelial cell line (ARPE-19) using a biodegradable nanoparticulate delivery system. A 19-mer antisense phosphorothioate oligonucleotide (PS-ODN) complementary to bases 6-24 relative to the translational start site of the VEGF mRNA, a sense PS-ODN and a mismatch PS-ODN were examined for the inhibition of secretion and mRNA expression of VEGF using an enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction, respectively. Nanoparticles of the antisense oligonucleotides were formulated using a poly(lactide-co-glycolide) (50:50) copolymer using a double emulsion solvent evaporation method. After preparing nanoparticles, drug loading, encapsulation efficiency and particle size were determined. The cells were exposed to either plain solution of oligonucleotide or nanoparticles of oligonucleotide from Day 3 through Day 6. Alternatively, the cells were incubated with PS-ODNs and lipofectin for 4 h on Day 4. In all studies, VEGF secretion and mRNA expression were determined on Day 6. The particle size, drug loading and encapsulation efficiency were 252 nm, 5.5% and 16.5%, respectively. The antisense PS-ODN inhibited VEGF mRNA and protein secretion when delivered using nanoparticles or lipofectin but not in its free form. This was consistent with the ability of nanoparticles and lipofectin to elevate the cellular uptake of the oligonucleotide by 4-fold and 13-fold, respectively. Neither mismatch nor sense oligonucleotides inhibited VEGF secretion. In conclusion, biodegradable nanoparticles enhance cellular delivery of a VEGF antisense oligonucleotide and inhibit VEGF secretion and mRNA expression in a human retinal pigment epithelial cell line.

A biodegradable injectable implant sustains systemic and ocular delivery of an aldose reductase inhibitor and ameliorates biochemical changes in a galactose-fed rat model for diabetic complications.

PURPOSE: To fabricate and characterize in vitro and in vivo performance of a sustained release biodegradable implant for N-4-(benzoylaminophenylsulfonyl glycine) (BAPSG), a novel aldose reductase inhibitor. METHODS: The ability of BAPSG to inhibit aldose reductase activity and glucose-induced vascular endothelial growth factor (VEGF) expression was assessed in a retinal pigment epithelial cell line (ARPE-19). A poly (DL-lactic-co-glycolic acid) implant containing 50% w/w BAPSG was fabricated and characterized for drug loading, in vitro drug release, and the thermal behavior of the drug and the polymer. Implants were injected subcutaneously into a galactose-fed diabetic rat model and cataract scores, plasma and tissue drug levels, galactitol levels in the lens and the retina, glutathione levels in the plasma, lens, cornea and retina and VEGF expression in the retina were determined on or until 18 days. RESULTS: BAPSG inhibited aldose reductase activity and reduced VEGF expression in ARPE-19 cells. Implants (1 x 4 mm), with a loading efficiency of 106 +/- 7% for BAPSG, were fabricated. Upon implant fabrication, while the glass transition temperature of the polymer decreased, the melting point of the drug was not affected. In vivo drug release correlated well with in vitro release, with approximately 44% drug release occurring in vivo by the end of 18 days. The implant reduced galactitol accumulation, glutathione depletion, cataract scores, and VEGF expression in galactose-fed rats. CONCLUSIONS: An injectable biodegradable implant of BAPSG sustained drug release in vitro and in vivo, and reduced galactitol accumulation, glutathione depletion, cataract scores, and VEGF expression in galactose-fed rats.