Redox- and pH-responsive fluorescent carbon nanoparticles-MnO₂-based FRET system for tumor-targeted drug delivery in vivo and in vitro

The carbonized boronic acid-conjugated fluorescent carbon nanoparticles (FNPs) were crosslinked with carbonized dopamine-conjugated hyaluronic acid (HA) via the diol boronic acid-linked catechol groups [C-FNP] as extracellular targeting ligands and pH responsiveness. Into that C-FNP, the redox-responsive MnO₂ nanosheets were loaded to demonstrate quenching effect, which recovered after glutathione (GSH) treatment. The MnO₂-loaded C-FNP showed excellent stability and tumor-targeting ability guided to the localized tumor using “on–off” fluorescent switch. Furthermore, paclitaxel (PTX) inside the MnO₂-loaded C-FNP performed in vitro and in vivo bioimaging and chemotherapeutic activities analyzed towards cancer and non-cancerous cells.