Charge-Convertible Carbon Dots for Imaging-Guided Drug Delivery with Enhanced in Vivo Cancer Therapeutic Efficiency

Abstract

Carbon dots (CDs) are remarkable nanocarriers due to their promising optical and biocompatible capabilities. However, their practical applicability in cancer therapeutics is limited by their insensitive surface properties to complicated tumor microenvironment in vivo. Herein, a tumor extracellular microenvironment-responsive drug nanocarrier based on cisplatin(IV) prodrug-loaded charge-convertible CDs (CDs-Pt(IV)@PEG-(PAH/DMMA)) was developed for imaging-guided drug delivery. An anionic polymer with dimethylmaleic acid (PEG-(PAH/DMMA)) on the fabricated CDs-Pt(IV)@PEG-(PAH/DMMA) could undergo intriguing charge conversion to a cationic polymer in mildly acidic tumor extracellular microenvironment (pH ∼ 6.8), leading to strong electrostatic repulsion and release of positive CDs-Pt(IV). Importantly, positively charged nanocarrier displays high affinity to negatively charged cancer cell membrane, which results in enhanced internalization and effective activation of cisplatin(IV) prodrug in the reductive cytosol. The in vitro experimental results confirmed that this promising charge-convertible nanocarrier possesses better therapeutic efficiency under tumor extracellular microenvironment than normal physiological condition and noncharge-convertible nanocarrier. The in vivo experiments further demonstrated high tumor-inhibition efficacy and low side effects of the charge-convertible CDs, proving its capability as a smart drug nanocarrier with enhanced therapeutic effects. The present work provides a strategy to promote potential clinical application of CDs in the cancer treatment.

Origin and Perspectives of the Photochemical Activity of Nanoporous Carbons

“…Discovery of graphene further advanced the study of photoluminescence of carbon‐based materials in the context of exciting applications of graphene/carbon quantum dots (CQDs) in bioimaging,160, 161, 162 drug delivery,163 photocatalysis,164, 165 electrocatalysis,165 photovoltaics,166, 167 and sensing 168. Those CQDs169 are a new form of fluorescent carbon nanostructures.…”

Characterization and Analytical Separation of Fluorescent Carbon Nanodots

“…Yang et al succeeded in using C-dots for the in vivo studies of optical imaging with mice for animal test. Followed by these, as a result of extensive and multidisciplinary efforts, C-dots have found their place in a wide range of applications in nanoprobes [56][57][58][59][60][61][62][63][64][65][66], drug delivery [67][68][69][70][71], therapy [72][73][74][75][76], and optoelectronic devices [77][78][79][80][81][82].…”

A review of drug delivery systems based on nanotechnology and green chemistry: green nanomedicine

“…In vivo experiments of charge-convertible CDs exhibited high tumor inhibition ability and low side effects as a smart nanodrug delivery with impressive therapeutic effects. 53 Bright green luminescent graphitic carbon nitride QDs (GCNQDs) doped with oxygen and sulfur were synthesized using citric acid and thiourea via a simple microwave method. The cell viability assay of GCNQDs demonstrated that GCNQDs can be used as a good and enhanced fluorescent probe for HeLa cell imaging with low cytotoxicity and high potential in bioanalysis and related research.…”