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Production and Targeting of Monovalent Quantum Dots
Published on: October 23, 2014
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Cytotoxicity and autophagy induction by graphene quantum dots with different functional groups
Yichun Xie1, Bin Wan1, Yu Yang1
1State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Journal of Environmental Sciences (China)
|December 22, 2018
Summary
Carboxyl-graphene quantum dots (cGQDs) exhibit excellent biocompatibility, unlike hydroxyl- and amino-modified GQDs which induce toxicity and autophagy. Autophagy plays a protective role against GQD toxicity, suggesting its importance in health risk assessments.
Area of Science:
- Nanomaterials Science
- Toxicology
- Cell Biology
Background:
- Graphene quantum dots (GQDs) offer promising applications due to unique properties and surface modifiability.
- Systematic toxicity assessment of GQDs, especially surface-modified variants, is crucial for safe development.
- The role of autophagy in GQD-induced cellular responses remains largely unexplored.
Purpose of the Study:
- To investigate the cytotoxicity and autophagy induction of three surface-modified GQDs (cGQDs, hGQDs, aGQDs) using A549 lung cancer cells.
- To elucidate the underlying molecular pathways of GQD-induced autophagy and its relationship with cytotoxicity.
- To evaluate the biocompatibility of different GQD surface modifications for potential biological applications.
Main Methods:
- Cytotoxicity was assessed using WST-1 assays and Annexin-V-FITC/PI staining.
- Autophagy was detected via transmission electron microscopy (TEM), LC3 fluorescence tracking, and Western blotting.
- Signaling pathways (p38MAPK, ERK1/2, JNK, Akt) and autophagy inhibition (3-MA) were analyzed.
Main Results:
- Hydroxyl-GQDs (hGQDs) exhibited significant cytotoxicity at 100 μg/mL, while carboxyl-GQDs (cGQDs) and amino-GQDs (aGQDs) were non-cytotoxic.
- aGQDs and hGQDs induced autophagy, whereas cGQDs did not.
- All GQDs activated p38MAPK; signaling pathways for ERK1/2, JNK, and Akt varied depending on GQD modification.
- Autophagy inhibition increased GQD cytotoxicity, indicating a protective role.
Conclusions:
- cGQDs demonstrate excellent biocompatibility and are suitable for biological applications.
- Autophagy induction by GQDs is linked to their toxicity and cellular stress response.
- Health risk assessments for GQDs should consider autophagy induction as an indicator of potential adverse effects.
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