title: Preparation and characterization of PLGA nanospheres for the targeted delivery of NR2B-specific antisense oligonucleotides to the NMDA receptors in the brain.
abstract: Treatment of central nervous system (CNS) diseases with potentially useful pharmaceuticals is prevented by the blood-brain barrier (BBB). The BBB is a unique protective barrier in the body. It is formed by epithelial-like tight junctions, which are expressed by the brain capillary endothelial cells. Although most molecules are potentially active in the CNS, they cannot readily enter the brain because of their properties. Antisense oligonucleotides (ODNs) have a great potential as neuropharmaceuticals; however, the large size and polar nature of nucleic acid drugs prevent these molecules from bypassing the BBB and readily entering the CNS following systemic administration. One approach to improve both the pharmacokinetics and the pharmacodynamics of ODNs involves the use of sustained-release polymer formulations, such as poly(lactide-co-glycolide) (PLGA) nanoparticulate systems. In this study, nanospheres were prepared by the emulsification diffusion technique and characterized in terms of particle size, surface morphology, encapsulation efficiency, in vitro release profiles and ODN stability. The nanospheres produced were spherical with homogenous size distribution. Nanospheres were prepared with different encapsulation efficiency. Release profiles of formulations were also evaluated. The results show that formulations with different ODN content exhibited different release profiles. Moreover, the chemical integrity of ODN during the processes was conserved. These results demonstrate that a stable ODN formulation could be prepared utilizing PLGA nanospheres as a potential delivery system for the treatment of CNS diseases.
authors.affiliation: Faculty of Pharmacy, Department of Pharmaceutical Technology, Hacettepe University, Ankara, Turkey.
authors.forename: A C
authors.initials: AC
authors.lastname: Kilic
authors.forename: Y
authors.initials: Y
authors.lastname: Capan
authors.forename: I
authors.initials: I
authors.lastname: Vural
authors.forename: R N
authors.initials: RN
authors.lastname: Gursoy
authors.forename: T
authors.initials: T
authors.lastname: Dalkara
authors.forename: A
authors.initials: A
authors.lastname: Cuine
authors.forename: A A
authors.initials: AA
authors.lastname: Hincal
mesh_terms: D001921:Brain / Q000378:metabolism*; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D019344:Lactic Acid / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D043942:Nanotubes / Q000737:chemistry*; D016376:Oligonucleotides, Antisense / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics*
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; C121001:NR2B NMDA receptor; D016376:Oligonucleotides, Antisense; D011108:Polymers; D016194:Receptors, N-Methyl-D-Aspartate; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid