title: Cytotoxicity of paclitaxel incorporated in PLGA nanoparticles on hypoxic human tumor cells.
abstract: OBJECTIVE
  The aim of this work was to prepare paclitaxel-loaded PLGA nanoparticles and determine cytotoxicity of released paclitaxel for two hypoxic human tumor cell lines: breast carcinoma (MCF-7) and carcinoma cervicis (HeLa).
  
  
  METHODS
  Poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles containing paclitaxel were prepared by o/w emulsification-solvent evaporation method. Physicochemical characteristics of nanoparticles were studied. Cellular uptake of nanoparticles was evaluated by transmission electronic microscopy and fluorescence microscopy. Flow cytometry quantified the number of cells held in G(2)/M phase. Cell viability was determined by the ability of single cell to form colonies. Biodistribution of nanoparticles in mice was evaluated by fluorescence microscopy.
  
  
  RESULTS
  The nanoparticles were spherical with average diameter 318 +/- 5.1 nm. The encapsulation efficiency was 88.52%. The drug release profile in vitro exhibited a biphasic pattern. Cellular uptake was observed. Co-culture of tumor cells with paclitaxel-loaded nanoparticles demonstrated that released paclitaxel retained its bioactivity to block cells in G(2)/M phase. Paclitaxel-loaded nanoparticles exhibited cytotoxic effect on both hypoxic MCF-7 and HeLa cells and its cytotoxicity was more significant than that of free paclitaxel. Fluorescent nanoparticles were mainly distributed to liver and spleen of mice.
  
  
  CONCLUSIONS
  Paclitaxel-loaded PLGA nanoparticles may be considered a promising drug delivery system to eradicate hypoxic tumor cells.
authors.affiliation: Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Jin
authors.forename: Ling
authors.initials: L
authors.lastname: Bai
authors.forename: Hong
authors.initials: H
authors.lastname: Wu
authors.forename: Wenjie
authors.initials: W
authors.lastname: Song
authors.forename: Guozhen
authors.initials: G
authors.lastname: Guo
authors.forename: Kefeng
authors.initials: K
authors.lastname: Dou
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity*; D001943:Breast Neoplasms / Q000188:drug therapy; D002277:Carcinoma / Q000188:drug therapy; D015687:Cell Hypoxia; D002470:Cell Survival / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry*; D005260:Female; D006367:HeLa Cells; D006801:Humans; D019344:Lactic Acid; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D017239:Paclitaxel / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity*; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004337:Drug Carriers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D017239:Paclitaxel