Electrochemical Nanopipette Sensor for In Vitro/In Vivo Detection of Cu2+ Ions.

In vitro/in vivo detection of copper ions is a challenging task but one which is important in the development of new approaches to the diagnosis and treatment of cancer and hereditary diseases such as Alzheimer's, Wilson's, etc. In this paper, we present a nanopipette sensor capable of measuring Cu2+ ions with a linear range from 0.1 to 10 µM in vitro and in vivo. Using the gold-modified nanopipette sensor with a copper chelating ligand, we evaluated the accumulation ability of the liposomal form of an anticancer Cu-containing complex at three levels of biological organization. First, we detected Cu2+ ions in a single cell model of human breast adenocarcinoma MCF-7 and in murine melanoma B16 cells. The insertion of the nanoelectrode did not result in leakage of the cell membrane. We then evaluated the distribution of the Cu-complex in MCF-7 tumor spheroids and found that the diffusion-limited accumulation was a function of the depth, typical for 3D culture. Finally, we demonstrated the use of the sensor for Cu2+ ion detection in the brain of an APP/PS1 transgenic mouse model of Alzheimer's disease and tumor-bearing mice in response to injection (2 mg kg-1) of the liposomal form of the anticancer Cu-containing complex. Enhanced stability and selectivity, as well as distinct copper oxidation peaks, confirmed that the developed sensor is a promising tool for testing various types of biological systems. In summary, this research has demonstrated a minimally invasive electrochemical technique with high temporal resolution that can be used for the study of metabolism of copper or copper-based drugs in vitro and in vivo.

The Centrosomes of Haploid and Diploid Cells Have an Equal Number of Centrioles in the Parasitoid Wasp Anisopteromalus Calandrae.

BACKGROUND: The centrosome is the main center of the organization of microtubules (MT) in the cell, the origin for the formation of flagella and cilia, as well as the site of many regulatory intracellular processes. In diploid cells, the centrosome includes two centrioles connected to some additional structures and surrounded by pericentriolar material. METHODS: The ultrastructure of the cells was studied using transmission electron microscopy on serial ultrathin sections. RESULTS: Here, using transmission electron microscopy on a complete series of ultrathin sections of the centrosome region, we studied the relation between the number of centrioles and ploidy in diploid cells of female wasps and haploid cells of male in the parasitoid wasp Anisopteromalus calandrae (Hymenoptera). It showed that the haploid cells of the male insect have the same number of centrioles as the diploid cells of the female. CONCLUSIONS: It can be concluded that there is no strict correlation between the number of chromosome sets (ploidy) and the number of centrioles in haplodiploid insects.