title: An innovative, quick and convenient labeling method for the investigation of pharmacological behavior and the metabolism of poly(DL-lactide-co-glycolide) nanospheres.
abstract: Nanoparticles of poly(DL-lactide-co-glycolide) (PLGA) in the size range 90-150 nm were produced using the physicochemical method with solvent/non-solvent systems. The encapsulation of the ascorbic acid in the polymer matrix was performed by homogenization of the water and organic phases. In vitro degradation and release tests of PLGA nanoparticles with and without encapsulated ascorbic acid were studied for more than 60 days in PBS and it has been determined that PLGA completely degrades within this period, fully releasing all encapsulated ascorbic acid. The cytotoxicity of PLGA and PLGA/ascorbic acid 85/15% nanoparticles was examined with human hepatoma cell lines (HepG2 ECACC), in vitro. The obtained results indicate that neither PLGA nanospheres nor PLGA/ascorbic acid 85/15% nanoparticles significantly affected the viability of the HepG2 cells. The investigation of the distribution and pharmacokinetics of PLGA is crucial for the effective prediction of host responses to PLGA in particular applications. Thus we present a method of labeling PLGA nanospheres and PLGA/ascorbic acid 85/15 wt% nanoparticles by (99m)Tc which binds outside, leaving the cage intact. This enables a quick and convenient investigation of the pharmacological behavior and metabolism of PLGA. The biodistribution of (99m)Tc-labeled PLGA particles with and without encapsulated ascorbic acid after different periods of time of their installation into rats was examined. PLGA nanospheres with encapsulated ascorbic acid exhibit prolonged blood circulation accompanied by time-dependent reduction in the lungs, liver and spleen, and addition in the kidney, stomach and intestine. The samples were characterized by x-ray diffraction, scanning electron microscopy, stereological analysis, transmission electron microscopy, ultraviolet spectroscopy and instant thin layer chromatography.
authors.affiliation: Institute of Technical Sciences of the Serbian Academy of Sciences and Arts, 11000 Belgrade, Serbia. magdalena.stevanovic@itn.sanu.ac.rs
authors.forename: Magdalena
authors.initials: M
authors.lastname: Stevanović
authors.forename: Tatjana
authors.initials: T
authors.lastname: Maksin
authors.forename: Jana
authors.initials: J
authors.lastname: Petković
authors.forename: Metka
authors.initials: M
authors.lastname: Filipic
authors.forename: Dragan
authors.initials: D
authors.lastname: Uskoković
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry / Q000493:pharmacokinetics; D002021:Buffers; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D006801:Humans; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology*; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D011100:Polyglycolic Acid / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017208:Rats, Wistar; D013056:Spectrophotometry, Ultraviolet; D013194:Staining and Labeling / Q000379:methods*; D017556:Technetium Compounds; D013997:Time Factors; D014018:Tissue Distribution / Q000187:drug effects; D014961:X-Ray Diffraction
chemical_list: D002021:Buffers; D017556:Technetium Compounds; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D001205:Ascorbic Acid