title: Poly(ethylene oxide)-modified poly(beta-amino ester) nanoparticles as a pH-sensitive system for tumor-targeted delivery of hydrophobic drugs: part 3. Therapeutic efficacy and safety studies in ovarian cancer xenograft model.
abstract: OBJECTIVE
  The objective of this study was to evaluate the anti-tumor efficacy and lack of systemic toxicity of paclitaxel when administered in pH-sensitive poly(ethylene oxide) (PEO)-modified poly(beta-amino ester) (PbAE) nanoparticles in mice bearing human ovarian adenocarcinoma (SKOV-3) xenograft.
  
  
  METHODS
  Paclitaxel-encapsulated PEO-modified PbAE (PEO-PbAE) nanoparticles were prepared by the solvent displacement method. PEO-modified poly(epsilon-caprolactone) (PCL) (PEO-PCL) nanoparticles were used as a non pH-responsive control formulation. Efficacy studies were conducted in SKOV-3 tumor-bearing athymic (Nu/Nu) mice at an equivalent paclitaxel dose of 20 mg/kg with the control and nanoparticle formulations. Safety of the drug when administered in the control and nanoparticle formulation was determined from blood cell counts and changes in body weight of the animals.
  
  
  RESULTS
  The formulated paclitaxel-containing PEO-PbAE and PEO-PCL nanoparticles had a particle size in the range of 100-200 nm and a surface charge of + 39.0 and - 30.8 mV, respectively. After intravenous administration of paclitaxel in these formulations, the tumor growth was inhibited significantly. Both of the formulated nanoparticles tested have shown improved therapeutic efficacy as compared to the paclitaxel aqueous solution. Additionally, significantly lower toxicity profile of paclitaxel was observed with PEO-modified nanoparticles as compared to the aqueous solution formulation
  
  
  CONCLUSIONS
  PEO-modified PbAE nanoparticles are a unique pH-sensitive drug delivery system that elicits enhanced efficacy and safety profile in solid tumor therapy.
authors.affiliation: Department of Pharmaceutical Sciences, School of Pharmacy, Northeastern University, Boston, MA 02115, USA.
authors.forename: Harikrishna
authors.initials: H
authors.lastname: Devalapally
authors.forename: Dinesh
authors.initials: D
authors.lastname: Shenoy
authors.forename: Steven
authors.initials: S
authors.lastname: Little
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
authors.forename: Mansoor
authors.initials: M
authors.lastname: Amiji
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical; D016503:Drug Delivery Systems; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D053758:Nanoparticles; D009368:Neoplasm Transplantation; D010051:Ovarian Neoplasms / Q000188:drug therapy*; D017239:Paclitaxel / Q000008:administration & dosage* / Q000009:adverse effects; D011091:Polyesters / Q000008:administration & dosage*; D011092:Polyethylene Glycols; D014183:Transplantation, Heterologous
chemical_list: D011091:Polyesters; C016240:polycaprolactone; D011092:Polyethylene Glycols; D017239:Paclitaxel