title: CD44-specific nanoparticles for redox-triggered reactive oxygen species production and doxorubicin release.
abstract: CD44-specific and redox-responsive nanoparticles were prepared by coating a bioreducible chitosan-based nanoparticles with hyaluronic acid for intracellular glutathione-triggered reactive oxygen species (ROS) production and doxorubicin (DOX) release. Chitosan (CS) was conjugated with a copper chelator, D-penicillamine (D-pen), to obtain a CS-SS-D-pen conjugate through the formation of a disulfide bond. D-pen release from the conjugate was triggered by intracellular glutathione (GSH) via reducing biologically reversible disulfide bonds. Self-assembled CS-SS-D-pen nanoparticles were prepared through ionotropic gelation with tripolyphosphate and subsequently coated with hyaluronic acid (HA). The HA-coated CS-SS-D-pen NPs were reduced by GSH to release free D-pen and trigger ROS production via a series of reactions involving Cu(II)-catalyzed D-pen oxidation and H2O2 generation. DOX was loaded into the HA-coated CS-SS-D-pen NPs by a method involving the complexation of DOX with Cu(II) ions. The Cu(II)-DOX complex-loaded NPs exhibited redox-responsive release properties which accelerated DOX release at a higher glutathione level (10mM). Confocal fluorescence microscopy demonstrated that the Cu(II)-DOX-loaded NPs effectively delivered DOX to human colon adenocarcinoma cells (HT-29) by active targeting via HA-CD44 interactions. Intracellular ROS generated from the HA-coated CS-SS-D-pen NPs sensitized cancer cells to DOX-induced cytotoxicity. In vitro cytotoxicity assays revealed that Cu(II)-DOX-loaded NPs sensitized cells to DOX-induced cytotoxicity in CD44-overexpressing HT-29 cells compared to CD44 low-expressing HCT-15 cells.
  
  
  CONCLUSIONS
  In this manuscript, we develop a CD44-targetable loaded with nanoparticles Cu(II)-DOX complex. The nanoparticles exhibited redox-responsive properties, which triggered reactive oxygen species (ROS) production and accelerated DOX release. The Cu(II)-DOX-loaded nanoparticle sensitized cells to DOX-induced cytotoxicity in CD44-overexpressing HT-29 cells. To our knowledge, this is the first report showing the combination of CD44-targeting and redox-responsive property for triggering ROS production and subsequent drug release. We believe our findings would appeal to the readership of Acta Biomaterialia because the study bring new and interesting ideals in the development of specific and stimuli-responsive nanoparticles as drug carrier for cancer therapy.
authors: Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
authors: Cheng-Wei
authors: CW
authors: Lin
authors: Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
authors: Kun-Ying
authors: KY
authors: Lu
authors: Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
authors: Sin-Yu
authors: SY
authors: Wang
authors: Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan; Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan. Electronic address: hwsung@mx.nthu.edu.tw.
authors: Hsing-Wen
authors: HW
authors: Sung
authors: Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan; Graduate Institute of Nanomedicine and Medical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan. Electronic address: flmi530326@tmu.edu.tw.
authors: Fwu-Long
authors: FL
authors: Mi
mesh_terms: D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D004317:Doxorubicin / Q000494:pharmacology*; D065546:Drug Liberation; D016650:Fluorescein-5-isothiocyanate / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D006820:Hyaluronic Acid / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000378:metabolism; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction / Q000187:drug effects; D010316:Particle Size; D010396:Penicillamine / Q000494:pharmacology; D066244:Proton Magnetic Resonance Spectroscopy; D017382:Reactive Oxygen Species / Q000378:metabolism*; D055672:Static Electricity
chemical_list: D004220:Disulfides; D018960:Hyaluronan Receptors; D017382:Reactive Oxygen Species; D004317:Doxorubicin; D006820:Hyaluronic Acid; D048271:Chitosan; D006861:Hydrogen Peroxide; D005978:Glutathione; D010396:Penicillamine; D016650:Fluorescein-5-isothiocyanate
keywords: CD44-targeting; Chitosan; Doxorubicin; Hyaluronic acid; Nanoparticles