Boron-Doped Carbon Nanodots as a Theranostic Agent for Colon Cancer Stem Cells.

Carbon nanodots have drawn a great deal of attention due to their green and expedient opportunities in biological and chemical sciences. Their high fluorescence capabilities and low toxicity for living cells and tissues make them excellent imaging agents. In addition, they have a fluorimetric response against inorganic and organic species. Boron-doped carbon nanodots (B-CDs) with high fluorescence yield were produced from phenylboronic acid and glutamine as boron and carbon sources, respectively, by a hydrothermal method. First, the effects of the temperature on their fluorescence yield and the structural characteristics of B-CDs were investigated. Second, their cytotoxicity and cell death and proliferation behaviors were examined. The cytotoxicity was evaluated by the MTT assay. The cellular properties were evaluated with the distribution of caspase 3, Ki67, lamin B1, P16, and cytochrome c after the indirect immunoperoxidase technique. After the MTT assay, 1:1 dilution of all applicants for 24 h was used in the study. After immunohistochemical analyses, the application of B-CDs synthesized at 230 °C did not change control cell (Vero) proliferation, and also apoptosis was not triggered. Colo 320 CD133+ and CD133- cell-triggered apoptosis and cellular senescence were found to be synthesis temperature dependent. In addition, Colo 320 CD133- cells were affected relatively more than CD133+ cells from B-CDs. While B-CDs did not affect the control cells, the colon cancer stem cells (Colo 320 CD133+) were affected in a time-dependent manner. Therefore, the use of the synthesized B-CD product may be an alternative method for controlling or eliminating cancer stem cells in the tumor tissue.

To what extent are orally ingested nanoplastics toxic to the hippocampus in young adult rats?

As the use of plastic-containing materials in our daily lives becomes increasingly common, exposure to nanoplastics accordingly becomes inevitable. Micro and nanoplastics released from large amounts of plastic waste constitute a serious environmental problem. Therefore, this study aimed to examine the effects of polystyrene nanoplastic (PS-NP) on the hippocampus. MATERIAL AND METHOD: Thirty Wistar albino rats, 15 male and 15 female, aged 6-8 weeks, were used in the research. These were randomly divided into three groups of five males and five females each. A five-minute open field test was applied to all rats on the first and last days of the study. Three groups of rats (Control, NP1 and NP2) received the standard chow and water. Additionally, rats in the first neoplastic group (NP1) received 25 mg/kg PS-NP and rats in the second nanoplastic group (NP2) received 50 mg/kg PS-NP, at the same time each day by oral gavage. The rats were sacrificed under deep anesthesia at the end of four weeks. The hippocampi were removed and subjected to histopathological and biochemical analyses. RESULTS: Green fluorescent dots were detected in the hippocampi of both dose groups receiving nanoplastics (NPs) administered orally to female and male rats. Histopathological examination revealed neuronal degeneration in the hippocampi of male and female rats from both dose groups. However, while no significant difference was observed among the groups in terms of changes in antioxidant enzyme values and open-field test data in male rats, significant differences in peroxidase (POD) and glutathione S-transferase (GST) values and fecal boli and grooming numbers were determined in female rats exposed to NPs. In conclusion, exposure to NP substances extend as far as the hippocampus, causing neuronal damage and behavioral problems.

Fluorescent and Biocompatible Nitrogen and Sulfur Co-Doped Carbon Nanodot as an Ocular Fundus Angiography Imaging Agent.

The florescence characteristics and the toxicities of carbon nanodots (CDs) are directly related to their elemental compositions. Fluorescent and non-toxic agent for imaging of biological systems was aimed. Sulfur and nitrogen co-doped CDs (S/N-CDs) was hydrothermally produced in an average size of 8 nm. S/N-CDs showed blue fluorescence under UV-light with an excitation wavelength of 365 nm. After 24 h, S/N-CDs was non-cytotoxic in HUVEC and L929 cells. S/N-CDs have a great potential to act as an alternative material for commercial fluorescent materials with its 85.5% of quantum yield. S/N-CDs was approved in vitro as an imaging agent for an ocular fundus angiography of rats.