Effect of single-walled carbon nanotubes on tumor cells viability and formation of multicellular tumor spheroids

Synthesis, antibacterial and anticancer activity of azo-based and aminomethylene derivatives of cyclic β-keto sulfones

Herein we describe efficient and cost-effective synthesis of azo-based and aminomethylene derivatives of cyclic β-keto sulfones, specifically, 4,4-disubstituted (E)-2-(2-phenylhydrazineylidene)dihydrothiophen-3(2H)-one 1,1-dioxides and 4,4-disubstituted (E)-2-((methylamino)methylene)dihydrothiophen-3(2H)-one 1,1-dioxides. The azo-based derivatives were prepared through the azo coupling of cyclic β-keto sulfones with aromatic diazonium acetates, in situ prepared by diazotization of appropriate substituted amino benzenes. The aminomethylene derivatives were synthesized through the condensation of cyclic β-keto sulfones with DMF-DMA followed by a transamination reaction with primary amines. The target products were obtained in good yields and their structure was unambiguously established based on NMR spectra data, X-ray diffraction study, and DFT calculations. These compounds were designed as cost-effective and multitarget biologically active compounds. Further in vitro study showed antibacterial activity against Staphylococcus aureus and cytotoxicity against the MDA-MB-231 breast cancer cell line without affecting non-malignant cells MAEC. The molecular docking study confirmed good binding affinity of the studied compounds for DHPS, crucial for the bacterial life cycle and for CLK4 and IDO1, which are the therapeutic targets in cancer treatment.

Enhanced methylene blue adsorption using single-walled carbon nanotubes/chitosan-graft-gelatin nanocomposite hydrogels

In the present study, single-walled carbon nanotubes (SWCNTs) incorporating chitosan-graft-gelatin (CS-g-GEL/SWCNTs) hydrogels were fabricated with multiple advantages, including cost-effectiveness, high efficiency, biodegradability, and ease of separation for methylene blue (MB) dye from aqueous solution. To verify the successful formulation of the prepared hydrogels, various characterization methods such as NMR, FTIR, XRD, FE-SEM, TGA, BET, and EDX were employed. The removal efficiency of CS-g-GEL/SWCNTs nanocomposite hydrogel increased significantly to 98.87% when the SWCNTs percentage was increased to 20%. The highest adsorption was observed for pH = 9, an adsorbent dose = 1.5 g L-1, a temperature = 25 °C, a contact time = 60 min, and a contaminant concentration = 20 mg L-1. Based on the thermodynamic results, spontaneous adsorption occurred from a negative Gibbs free energy (ΔG°). In addition, the thermodynamic analysis of the adsorption process revealed an average enthalpy of - 21.869 kJ mol-1 for the adsorption process at a temperature range of 25-45 °C, which indicates its spontaneous and exothermic behavior. The Langmuir isotherm model was successfully used to describe the equilibrium behavior of adsorption. The pseudo-first-order model better described adsorption kinetics compared to the pseudo-second-order, intra-particle, and Elovich models. CS-g-GEL/SWCNTs hydrogels have improved reusability for five consecutive cycles, suggesting that they may be effective for removing anionic dyes from aquatic environments.

Single-walled carbon nanotube, multi-walled carbon nanotube and Fe2O3 nanoparticles induced mitochondria mediated apoptosis in melanoma cells

PURPOSE

Nanomaterials (NM) exhibit novel anticancer properties.

MATERIALS AND METHODS

The toxicity of three nanoparticles that are currently being produced in high tonnage including single-walled carbon nanotube (SWCNT), multi-walled carbon nanotube (MWCNT) and Fe₂O₃ nanoparticles, were compared with normal and melanoma cells.

RESULTS

All tested nanoparticles induced selective toxicity and caspase 3 activation through mitochondria pathway in melanoma cells and mitochondria cause the generating of reactive oxygen species (ROS), mitochondrial membrane potential decline (MMP collapse), mitochondria swelling, and cytochrome c release. The pretreatment of butylated hydroxytoluene (BHT), a cell-permeable antioxidant and cyclosporine A (Cs. A), a mitochondrial permeability transition (MPT), pore sealing agent decreased cytotoxicity, caspase 3 activation, ROS generation, and mitochondrial damages induced by SWCNT, MWCNT, and IONPs.

CONCLUSIONS

Our promising results provide a potential approach for the future therapeutic use of SWCNT, MWCNT, and IONPs in melanoma through mitochondrial targeting.

In Vitro Study of Influence of Au Nanoparticles on HT29 and SPEV Cell Lines

Cell culture models are excellent tools for potential toxicity of nanoparticles and fundamental investigations in cancer research. Thus, information about AuNP potential toxicity and effects on human health is necessary for the use of nanomaterials in clinical settings. The aim of our research is to examine the effects of AuNPs on the epithelial origin cell lines: continuous and oncogenic. Embryonic porcine kidney epithelial inoculated (SPEV) cell line and colorectal carcinoma cell line (HT29) were used. In the test cultures, the cell proliferation, necrosis/apoptosis, and multicellular spheroids generation were evaluated. We demonstrated that AuNP concentrations of 6-12 μg/ml reduced the proliferation of SPEV and HT29 cells and increased the cell number at early and late stages of apoptosis and necrosis. It was shown that small concentrations of AuNPs (1-3 μg/ml) stimulate multicellular spheroid formation by HT29 and SPEV cells. However, higher AuNP concentrations (6-12 μg/ml) had both cytotoxic and anti-cohesive effects on cell in suspension. The large sensitiveness to the action of AuNPs was shown by the line of HT29 (6 μg/ml) as compared to the SPEV cells (12 μg/ml). This experimental study of the effect of AuNPs on SPEV and HT29 cell lines will justify their further application in AuNP-mediated anticancer treatment.

Methods: Using Three-Dimensional Culture (Spheroids) as an In Vitro Model of Tumour Hypoxia

Regions of hypoxia in tumours can be modelled in vitro in 2D cell cultures with a hypoxic chamber or incubator in which oxygen levels can be regulated. Although this system is useful in many respects, it disregards the additional physiological gradients of the hypoxic microenvironment, which result in reduced nutrients and more acidic pH. Another approach to hypoxia modelling is to use three-dimensional spheroid cultures. In spheroids, the physiological gradients of the hypoxic tumour microenvironment can be inexpensively modelled and explored. In addition, spheroids offer the advantage of more representative modelling of tumour therapy responses compared with 2D culture. Here, we review the use of spheroids in hypoxia tumour biology research and highlight the different methodologies for spheroid formation and how to obtain uniformity. We explore the challenge of spheroid analyses and how to determine the effect on the hypoxic versus normoxic components of spheroids. We discuss the use of high-throughput analyses in hypoxia screening of spheroids. Furthermore, we examine the use of mathematical modelling of spheroids to understand more fully the hypoxic tumour microenvironment.