Biomedical application of graphitic carbon nitrides: tissue depositionin vivo, induction of reactive oxygen species (ROS) and cell viability in tumor cells

Graphitic carbon nitride as a novel anticancer agent: potential mechanisms and efficacy in prostate cancer and glioblastoma treatment

Carbon-derived compounds are gaining traction in the scientific community because of their unique properties, such as conductivity and strength, and promising innovations in technology and medicine. Graphitic nitride carbon (g-C3N4) stands out among these compounds because of its potential in antitumor therapies. This study aimed to assess g-C3N4's antitumor potential and cytotoxic mechanisms. Prostate cancer (DU-145) and glioblastoma (U87) cell lines were used to evaluate antitumor effects, whereas RAW 264.7 and HFF-1 non-tumor cells were used for selectivity evaluation. The synthesized g-C3N4 particles underwent comprehensive characterization, including the assessment of particle size, morphology, and oxygen content, employing various techniques, such as X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, and atomic force microscopy. The results indicated that g-C3N4 significantly affected tumor cell proliferation and viability, exhibiting high cytotoxicity within 48 h. In non-tumor cells, minimal effects on proliferation were observed, except for damage to the cell membranes of RAW 264.7 cells. Moreover, g-C3N4 changed the cell morphology and ultrastructure, affecting cell migration in U87 cells and potentially enhancing migration in RAW 264.7 cells. Biochemical assays in Balb/C mice revealed alterations in alanine aminotransferase, aspartate aminotransferase, and amylase levels. In conclusion, g-C3N4 demonstrated promising antitumor effects with minimal toxicity to non-tumor cells, suggesting its potential in neoplasm treatment.

Sonoactivated Cascade Fenton Reaction Enhanced by Synergistic Modulation of Electron-Hole Separation for Improved Tumor Therapy

Chemodynamic therapy (CDT) is an emerging targeted treatment technique for tumors via the generation of highly cytotoxic hydroxyl radical (·OH) governed by tumor microenvironment-assisted Fenton reaction. Despite high effectiveness, it faces limitations like low reaction efficiency and limited endogenous H2 O2 , compromising its therapeutic efficacy. This study reports a novel platform with enhanced CDT performance by in situ sono-activated cascade Fenton reaction. A piezoelectric g-C3 N4 (Au-Fe-g-C3 N4 ) nanosheet is developed via sono-activated synergistic effect/H2 O2 self-supply mediated cascade Fenton reaction, realizing in situ ultrasound activated cascade Fenton reaction kinetics by synergistic modulation of electron-hole separation. The nanosheets consist of piezoelectric g-C3 N4 nanosheet oxidizing H2 O to highly reactive H2 O2 from the valence band, Fe3+ /Fe2+ cycling activated by conduction band to generate ·OH, and Au nanoparticles that lower the bandgap and further adopt electrons to generate more 1 O2 , resulting in improved CDT and sonodynamic therapy (SDT). Moreover, the Au-Fe-g-C3 N4 nanosheet is further modified by the targeted peptide to obtain P-Au-Fe-g-C3 N4 , which inhibits tumor growth in vivo effectively by generating reactive oxygen species (ROS). These results demonstrated that the sono-activated modulation translates into a high-efficiency CDT with a synergistic effect using SDT for improved anti-tumor therapy.

TFEB-lysosome pathway activation is associated with different cell death responses to carbon quantum dots in Kupffer cells and hepatocytes

Background

Carbon dot has been widely used in biomedical field as a kind of nanomaterial with low toxicity and high biocompatibility. CDs has demonstrated its unique advantages in assisted drug delivery, target diagnosis and targeted therapy with its small size and spontaneous fluorescence. However, the potential biosafety of CDs cannot be evaluated. Therefore, we focused on the study of liver, the target organ involved in CDs metabolism, to evaluate the risk of CDs in vitro.

Methods and results

Liver macrophage KUP5 cells and normal liver cells AML12 cells were incubated in CDs at the same concentration for 24 h to compare the different effects under the same exposure conditions. The study found that both liver cell models showed ATP metabolism disorder, membrane damage, autophagosome formation and lysosome damage, but the difference was that, KUP5 cells exhibited more serious damage than AML12 cells, suggesting that immunogenic cell type is particularly sensitive to CDs. The underlying mechanism of CDs-induced death of the two hepatocyte types were also assessed. In KUP5 cells, death was caused by inhibition of autophagic flux caused by autophagosome accumulation, this process that was reversed when autophagosome accumulation was prevented by 3-MA. AML12 cells had no such response, suggesting that the accumulation of autophagosomes caused by CDs may be specific to macrophages.

Conclusion

Activation of the TFEB-lysosome pathway is important in regulating autophagy and apoptosis. The dual regulation of ERK and mTOR phosphorylation upstream of TFEB influences the death outcome of AML12 cells. These findings provide a new understanding of how CDs impact different liver cells and contribute to a more complete toxicological safety evaluation of CDs.

Radiolabeled nanomaterials for biomedical applications: radiopharmacy in the era of nanotechnology

BACKGROUND

Recent advances in nanotechnology have offered new hope for cancer detection, prevention, and treatment. Nanomedicine, a term for the application of nanotechnology in medical and health fields, uses nanoparticles for several applications such as imaging, diagnostic, targeted cancer therapy, drug and gene delivery, tissue engineering, and theranostics.

RESULTS

Here, we overview the current state-of-the-art of radiolabeled nanoparticles for molecular imaging and radionuclide therapy. Nanostructured radiopharmaceuticals of technetium-99m, copper-64, lutetium-177, and radium-223 are discussed within the scope of this review article.

CONCLUSION

Nanoradiopharmaceuticals may lead to better development of theranostics inspired by ingenious delivery and imaging systems. Cancer nano-theranostics have the potential to lead the way to more specific and individualized cancer treatment.