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Folic-Acid, Cell Turnover, Binding-Protein, Cancer, Delivery, Receptor, Expression, Cytotoxicity, Differentiation, Trafficking

Using nanoparticles as carriers for drug delivery systems has become a widely applied strategy in therapeutics and diagnostics. However, the pattern of their intracellular distribution is yet to be clarified. Here we present an in vitro study on the incorporation of mesoporous silica nanoparticles conjugated with folate and loaded with a cytotoxic drug, Irinotecan. The nanoparticles count and distribution within the cell frame were evaluated by means of enhanced dark field microscopy combined with hyperspectral imagery and 3D reconstructions from double-labeled fluorescent samples. An original post-processing procedure was developed to emphasize the nanoparticles’ localization in 3D reconstruction of cellular compartments. By these means, it has been shown that the conjugation of mesoporous silica nanoparticles with folate increases the efficiency of nanoparticles entering the cell and their preferential localization in the close vicinity of the nucleus. As revealed by metabolic viability assays, the nanoparticles functionalized with folate enhance the cytotoxic efficiency of Irinotecan.

Polygonum bistorta, Polyphenols, Antioxidant, Cytotoxicity, Fibroblast cells, NIH3T3

This work aimed to study the polyphenols content, the antioxidant activity and the potential cytotoxic effects on fibroblast
murine cells NIH3T3 of an ethanolic extract (70%, v/v) obtained from the aerial part (herba et flores) of Polygonum bistorta
L. (Polygonaceae family). The tested extract was assessed for its total phenols content: 1.15 mg gallic acid equivalents
(GAE) per 1 mL extract and showed numerous flavonoids compounds such as quercetin, kaempferol and luteolin derivates,
as well as caffeic and chlorogenic phenolic acids. The chemiluminescence (CL) tests indicated a high antioxidant capacity
(IC50 = 0.57 µg GAE/mL), superior to gallic acid (IC50 = 0.85 µg/mL) and rutin (IC50 = 2.54 µg/mL), used as reference
compounds. The cytotoxicity test demonstrated that, at concentrations over 25 µg GAE/mL extract, the ethanolic extracts
from the aerial part of Polygonum bistorta plant species have a significant toxicity on mouse embryonic fibroblast NIH3T3 cells.

Aminoglycosides, Pseudomonas Aeruginosa, Endothelial Cells

The membrane organization of cultured human endothelial cells (EA.hy926) infected with Pseudomonas aeruginosa (PS) was studied in the temperature range 15–37 oC by using fluorescent depolarization and generalized polarization (GP) measurements on the cells suspensions labeled with TMA-DPH and laurdan, respectively. The opportunistic pathogen Pseudomonas aeruginosa was chosen since this pathogen is the etiologic agent of resistant and recurrent pulmonary infections in cystic fibrosis (CF) patients, who require sustained treatment with antibiotics. The effect of several aminoglycoside antibiotics – gentamicin, amikacin and kanamycin – on membrane organization of infected cultured cells was recorded. The measurements results showed that the presence of aminoglycosides cations induces a rigidity of the infected cell membrane, gentamicin being the most efficient in this respect. This effect is temperature sensitive, being much more pronounced at temperatures close to physiological range. The above information may be of use in determining the treatment regimen of a CF patient who has recurrent infections and requires antibiotics treatment for a longer time.