CD44-specific nanoparticles for redox-triggered reactive oxygen species production and doxorubicin release.

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. STATEMENT OF SIGNIFICANCE: 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.

EGCG/gelatin-doxorubicin gold nanoparticles enhance therapeutic efficacy of doxorubicin for prostate cancer treatment.

AIM: Development of epigallocatechin gallate (EGCG) and gelatin-doxorubicin conjugate (GLT-DOX)-coated gold nanoparticles (DOX-GLT/EGCG AuNPs) for fluorescence imaging and inhibition of prostate cancer cell growth. MATERIALS & METHODS: AuNPs alternatively coated with EGCG and DOX-GLT conjugates were prepared by a layer-by-layer assembly method. The physicochemical properties of the AuNPs and the effect of Laminin 67R receptor-mediated endocytosis on the anticancer efficacy of the AuNPs were examined. RESULTS: The AuNPs significantly inhibit the proliferation of PC-3 cancer cell and the enzyme-responsive intracellular release of DOX could be tracked by monitoring the recovery of the fluorescence signal of DOX. CONCLUSION: Laminin 67R receptor-mediated delivery of DOX using the AuNPs enhanced cellular uptake of DOX and improved apoptosis of PC-3 cells.