title: Poly(ethylene glycol)-b-poly(lysine) copolymer bearing nitroaromatics for hypoxia-sensitive drug delivery.
abstract: Hypoxia occurs in a variety of pathological conditions including stroke, rheumatoid arthritis, atherosclerosis, and tumors. In this study, an amphiphilic block copolymer, composed of poly(ethylene glycol) as the hydrophilic block and poly(ε-(4-nitro)benzyloxycarbonyl-L-lysine) as the hydrophobic block, was prepared for hypoxia-sensitive drug delivery. Owing to its amphiphilic nature, the block copolymer formed micelles and encapsulated doxorubicin (DOX) in an aqueous condition. The DOX-loaded micelles exhibited rapid intracellular release of DOX under the hypoxic condition, implying high potential as a drug carrier for cancer therapy.
  
  
  CONCLUSIONS
  Hypoxia occurs in a variety of pathological conditions including stroke, rheumatoid arthritis, atherosclerosis, and tumors. In this study, we developed a novel type of hypoxia-sensitive polymeric micelles (HS-PMs) that can specifically release the drug under the hypoxic conditions. HS-PMs were prepared using poly(ethylene glycol) as the hydrophilic block and poly(ε-(4-nitro)benzyloxycarbonyl-L-lysine) as the hydrophobic block. Owing to its amphiphilic nature, the block copolymer formed micelles and encapsulated doxorubicin (DOX) in an aqueous condition. The DOX-loaded micelles exhibited rapid intracellular release of DOX under the hypoxic condition. Overall, it is evident that the HS-PMs prepared in this study have the potential to effectively deliver hydrophobic drugs into the hypoxic cells involved in various intractable diseases.
authors.affiliation: School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Thavasyappan
authors.initials: T
authors.lastname: Thambi
authors.affiliation: Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Soyoung
authors.initials: S
authors.lastname: Son
authors.affiliation: School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea.
authors.forename: Doo Sung
authors.initials: DS
authors.lastname: Lee
authors.affiliation: School of Chemical Engineering, College of Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Suwon 440-746, Republic of Korea. Electronic address: jhpark1@skku.edu.
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Park
mesh_terms: D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D003692:Delayed-Action Preparations / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D004317:Doxorubicin / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D009578:Nitrobenzenes / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D011107:Polylysine / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology
chemical_list: D003692:Delayed-Action Preparations; D009578:Nitrobenzenes; D011107:Polylysine; D011092:Polyethylene Glycols; D004317:Doxorubicin; C000595209:polyethylene glycol 1000
keywords: Block copolymer; Cancer; DOX; Drug delivery; Hypoxia