Abstract
Purpose:
Cornea is a main barrier for drug penetration after topical application. The aim of this study was to evaluate the ability of corneal penetration by newly generated micelles based on tri-block copolymer with a positive charge.
Methods:
The tri-block copolymer poly (ethylene glycol)-poly (ε-caprolactone)-g-polyethylenimine (mPEG-PCL-g-PEI) was synthesized. The physicochemical properties of the self-assembled polymeric micelles were investigated including hydrodynamic sizes, zeta potentials, the morphology, the drug loading content (DLC), drug loading efficiency (DLE) and in vitro drug release. The behavior of polymeric micelles penetration was in vivo monitored using a two-photon scanning fluorescence microscopy on murine corneas after topical application.
Results:
The polymeric micelles had a particle size of 28 nm and a zeta potential of approximately +12 mV, with spherical in morphology. DLE and DLC were 75.37% and 3.47%, respectively. The release of polymeric micelles showed a control-release behavior in vitro. The polymeric micelles with positive charge penetrated significantly across the cornea compared with the control in vivo.
Conclusions:
Positively charged micelles based on triblock copolymer is a promising vehicle for the topical delivery of hydrophobic agents in ocular applications.