Graphitic carbon nitride (g-C3N4), an engineered carbon nanomaterial with tunable electronic structure, chemical stability, and biocompatibility, has promising applications in photocatalytic therapy, targeted drug delivery, and pollutant degradation. However, its transformations in biological and environmental systems (e.g., chemical protonation) can alter surface chemistry, charge distribution, and nanoscale topology, thereby affecting its biological interactions and toxicity.
In a study (DOI: 10.1016/j.enceco.2025.05.025) published in the KeAi journal Environmental Chemistry and Ecotoxicology, a group of researchers from the Guangdong University of Technology, China, investigated the cytotoxicity evolution of protonated carbon nitride (p-C3N4) toward red blood cells and elucidated its underlying mechanisms.
“Hemolysis assays showed that p-C3N4 exhibits enhanced phospholipid membrane-rupturing capabilities compared to pristine g-C3N4, with no significant lipid peroxidation detected,” shares lead and co-corresponding author Yiping Feng. “Surface characterization revealed that protonation reduces the net negative charge of carbon nitride, increasing its affinity with phospholipid membranes.”
Through molecular docking simulations, the researchers observed that interactions between p-C3N4 and phospholipid molecules were governed by electrostatic and hydrophobic forces, as well as hydrogen bonding with oxygen-containing functional groups.
“Molecular dynamics simulations further revealed that larger oxygen-bearing macropores on p-C3N4 allow for tight and specific binding with phospholipid headgroups, facilitating efficient lipid extraction and intensifying membrane disruption,” adds Feng.
The team’s findings provide critical insights into the cytotoxic changes that carbon nitride materials may undergo during transformations. They also highlight opportunities to mitigate associated risks or use surface protonation for enhanced functionality in carbon nitride-based technologies.
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References
DOI
10.1016/j.enceco.2025.05.025
Original Source URL
https://doi.org/10.1016/j.enceco.2025.05.025
Funding information
This study was supported by the Basic Science Center Project of the Natural Science Foundation of China (52388101), the Program for Guangdong Introducing Innovative and Entrepreneurial Teams (2019ZT08L213), the National Natural Science Foundation of China (21707019), the Natural Science Foundation of Guangdong Province (2021A1515010019), and the Research Fund Program of Guangdong Provincial Engineering Research Center of Intelligent Low-Carbon Pollution Prevention and Digital Technology/SCNU (NAN’AN) Green and Low-Carbon Innovation Center (2024K04).
About Environmental Chemistry and Ecotoxicology
Environmental Chemistry and Ecotoxicology publishes studies that examine the environmental chemistry (distribution, dynamics and fate) of pollutants, the biologic and toxic effects of man-made chemical pollutants on ecotoxicological animal models and plants.