title: Positively charged micelles based on a triblock copolymer demonstrate enhanced corneal penetration.
abstract: OBJECTIVE
  The cornea is a main barrier to drug penetration after topical application. The aim of this study was to evaluate the abilities of micelles generated from a positively charged triblock copolymer to penetrate the cornea after topical application.
  
  
  METHODS
  The triblock copolymer poly(ethylene glycol)-poly(ε-caprolactone)-g-polyethyleneimine was synthesized, and the physicochemical properties of the self-assembled polymeric micelles were investigated, including hydrodynamic size, zeta potential, morphology, drug-loading content, drug-loading efficiency, and in vitro drug release. Using fluorescein diacetate as a model drug, the penetration capabilities of the polymeric micelles were monitored in vivo using a two-photon scanning fluorescence microscopy on murine corneas after topical application.
  
  
  RESULTS
  The polymer was successfully synthesized and confirmed using nuclear magnetic resonance and Fourier transform infrared. The polymeric micelles had an average particle size of 28 nm, a zeta potential of approximately +12 mV, and a spherical morphology. The drug-loading efficiency and drug-loading content were 75.37% and 3.47%, respectively, which indicates that the polymeric micelles possess a high drug-loading capacity. The polymeric micelles also exhibited controlled-release behavior in vitro. Compared to the control, the positively charged polymeric micelles significantly penetrated through the cornea.
  
  
  CONCLUSIONS
  Positively charged micelles generated from a triblock copolymer are a promising vehicle for the topical delivery of hydrophobic agents in ocular applications.
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Jingguo
authors.initials: J
authors.lastname: Li
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Zhanrong
authors.initials: Z
authors.lastname: Li
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Tianyang
authors.initials: T
authors.lastname: Zhou
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Huiyun
authors.initials: H
authors.lastname: Xia
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Jijun
authors.initials: J
authors.lastname: He
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Siyu
authors.initials: S
authors.lastname: He
authors.affiliation: Henan Eye Institute, Henan Eye Hospital, Henan Provincial People's Hospital and Zhengzhou University People's Hospital, Zhengzhou, People's Republic of China.
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
mesh_terms: D000818:Animals; D003315:Cornea / Q000187:drug effects*; D057927:Hydrophobic and Hydrophilic Interactions; D051379:Mice; D008810:Mice, Inbred C57BL; D008823:Micelles; D018613:Microscopy, Confocal; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000008:administration & dosage* / Q000737:chemistry*
chemical_list: D008823:Micelles; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; D011092:Polyethylene Glycols
keywords: controlled release; corneal barriers; corneal penetration; polymeric micelles; topical administration