Permeability enhancement of Escherichia coli by single-walled carbon nanotube treatment

This research investigated the use of single-walled carbon nanotubes (SWNTs) as an additive to increase the permeability of a bacterial cell wall. Recombinant Escherichia coli BL21 (DE3) that expressed β-lactamase were exposed to SWNTs under various levels of concentration and agitation. Activity of β-lactamase in the culture fluid and transmission electron microscopy (TEM) were used to determine the amount of released protein, and visually examine the permeability enhancement of the cells. It was found that β-lactamase release in the culture fluid occurred in a dose-dependent manner with treatment by SWNTs and was also dependent on agitation rate. Based on TEM, this treatment successfully caused an increase in permeability without significant damage to the cell wall. Consequently, SWNTs can be used as an enhancement agent to cause the release of intracellular proteins. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:654-657, 2017.

Photo-assisted inactivation of Escherichia coli bacteria by silver functionalized titanate nanotubes, Ag/H2Ti2O5·H2O

One-dimensional titanate nanotubes functionalized with silver nanoparticles exhibit unique properties for the effective inactivation of the Gram-negative E. coli in 45 min. under irradiation using a 65 W halogen lamp.

Membrane permeabilization by conjugated oligoelectrolytes accelerates whole-cell catalysis

Conjugated oligoelectrolytes (COE) increase outer membrane permeability inEscherichia coli,improve transport of small molecules through the cell envelope and thus accelerate whole-cell catalysis.

Understanding the toxicity of carbon nanotubes in the environment is crucial to the control of nanomaterials in producing and processing and the assessment of health risk for human: a review

With the development and application of carbon nanotubes (CNTs), the potential hazards of CNTs to biological systems and the environment are getting more and more attention. This review evaluated the effects of physicochemical properties of CNTs on toxicity and summarized the advances on the mechanism of CNTs toxicity. We also proposed the possible hazards associated with CNTs and harmful effects resulting from exposure of aquatic animals, bacteria and higher plants to CNTs in vitro and in vivo. The current knowledge and gaps on CNTs were outlined as a potential problem for the environment and human health. The current research gaps on CNTs toxicity were identified and the further studying focus was proposed, too. This essay concluded with a set of recommendations for the advancement of understanding of the role of CNTs and future challenges in environmental and ecotoxicological research.

Combination of single walled carbon nanotubes/graphene oxide with paclitaxel: a reactive oxygen species mediated synergism for treatment of lung cancer

Heterogeneity in tumors has led to the development of combination therapies that enable enhanced cell death. Previously explored combination therapies mostly involved the use of bioactive molecules. In this work, we explored a non-conventional strategy of using carbon nanostructures (CNs) [single walled carbon nanotube (SWNT) and graphene oxide (GO)] for potentiating the efficacy of a bioactive molecule [paclitaxel (Tx)] for the treatment of lung cancer. The results demonstrated enhanced cell death following combination treatment of SWNT/GO and Tx indicating a synergistic effect. In addition, synergism was abrogated in the presence of an anti-oxidant, N-acetyl cysteine (NAC), and was therefore shown to be reactive oxygen species (ROS) dependent. It was further demonstrated using bromodeoxyuridine (BrdU) incorporation assay that treatment with CNs was associated with enhanced mitogen associated protein kinase (MAPK) activation that was ROS mediated. Hence, these results for the first time demonstrated the potential of SWNT/GO as co-therapeutic agents with Tx for the treatment of lung cancer.