Imaging Cellular Aerobic Glycolysis using Carbon Dots for Early Warning of Tumorigenesis

Abstract

is crucial for developing a better understanding of how tumors develop and progress. In this context, great achievements have been made using fluorescence imaging to detect tumors with high sensitivity and quality. [2-4] The current fluorescence-imaging strategies used to identify tumor cells are based on the conjugation of ligands and targeting of receptors, including peptides, proteins, antibodies, and aptamers. [5,6] However, it is difficult to realize early warning of tumor formation using fluorescence imaging before the development of in situ tumor tissues due to the lack of characteristic receptors in the tumorigenesis process. In most types of tumor, the energy metabolism pattern changes from oxidative phosphorylation to aerobic glycolysis and so a metabolic pattern characterized by abnormal glycolysis can be closely related to the development and progression of tumors. [7,8] Nicotinamide adenine dinucleotide (reduced, NADH; oxidized, NAD +) is a cofactor that plays a central role in cellular electron transfer (redox) reactions, wherein it alternates between its oxidized and reduced Early warning of tumor formation is crucial for the classification, treatment, and prognosis of tumor patients. Here, a new strategy is reported, aimed at realizing this goal based on imaging aerobic glycolysis processes using nitrogen-doped carbon dots (N-CDs) as fluorescent probes. The intensity of the photoluminescence emitted by the N-CDs is specifically enhanced by nicotinamide adenine dinucleotide (NAD + , oxidized) in the physiological environment. The N-CDs allow a few (five to ten) abnormal cells in spontaneous hepatocellular carcinoma models to be identified before the in situ development of tumor tissue. The N-CD probes can also distinguish tumor cells from normal cells and be used to evaluate their proliferation activity (with a specificity of up to 96.15% in 13 types of tumor cells and 90.90% in orthotopic xenograft models). The N-CDs are successfully used to monitor the invasion of tumor cells into neighboring tissues and body fluids in 49 clinical samples (with a sensitivity up to 79.31%). These included three vitreous body samples (from patients with retinoblastoma), 42 urine samples (22 patients clinically diagnosed with urothelium carcinoma and 20 healthy persons), and four hydrothorax samples (from patients with metastatic lesions).

Metformin Carbon Dots for Promoting Periodontal Bone Regeneration via Activation of ERK/AMPK Pathway

“…[ 25 ] Carbon dots (CDs), a new type of fluorescent nanomaterial, [ 26,27 ] display unique properties of small size, facile preparation, low cost, good biocompatibility, and excellent optical properties. [ 27–30 ] Therefore, CDs have attracted particular attention in various biomedical applications, [ 29–34 ] including in the field of bone regeneration. [ 35,36 ] The various medications provide abundant raw materials for preparing CDs.…”

Preparation, Properties, and Application of Lignocellulosic‐Based Fluorescent Carbon Dots

“…CDs will not damage organisms’ life activity when they enter the organisms because of its good biocompatibility of CDs. As for extracorporeal cell imaging, Li et al [136] . found that CDs were not only limited to clathrin‐mediated endocytosis and active transported into cytosol, but they could also enter cells through free diffusion.…”

Two-dimensional quantum dots for biological applications

“…The carbon dots were originated from the fragments of singlewalled carbon nanotubes (SWCNTs), which can be refined into graphene quantum dots (GQDs) and carbon quantum dots (CQDs), according to the hybridization and crystallinity of nanomaterials [66,69]. As traditional fluorescent nanoparticles, carbon dots were revalued in recent years since the exceptional chemical properties [17,29,33], including low toxicity, outstanding biocompatibility, and chemical inertness, endowed promising biological applications [27,34,40], such as biosensing, medical diagnosis, bioimaging, and tumor therapy.…”