Cytotoxicity of selenium nanoparticles in rat dermal fibroblasts
Authors: Joseph F Ramos
Thomas J Webster
Journal: International Journal of Nanomedicine (2012)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: cytotoxicity; fibroblast; nanoparticle; selenium; ventilator-associated pneumonia.

Abstract:  Background: Ventilator-associated pneumonia is a deadly nosocomial infection caused by contaminated endotracheal tubes. It has been shown that polyvinyl chloride (PVC, the endotracheal tube substrate) coated with elemental selenium nanoparticles reduces bacterial adherence and proliferation on PVC by over 99%. However, it is not known if selenium nanoparticles elicit a cytotoxic effect in vitro. The purpose of this study was to investigate the cytotoxic effects of PVC coated with selenium nanoparticles on fibroblasts, which are mammalian cells central to endotracheal tube intubation. Methods: Different concentrations of selenium nanoparticles were precipitated onto the PVC surface by reduction of selenium salts using glutathione. Characterization of PVC coated with selenium nanoparticles was done by scanning electron microscopy, energy dispersive x-ray, and contact angle measurements. For the cytotoxicity experiments, fibroblasts were seeded at a density of 5000 cm(2) onto PVC coated with three different concentrations of selenium nanoparticles (high, medium, low) and incubated for 4 hours (adhesion) as well as for 24 hours and 72 hours (proliferation). The half-maximal inhibitory concentration (IC(50)) value was determined after 72 hours using an ultrahigh concentration. MTT assays were used to assess cell viability at the indicated time points. Results: The three concentrations of selenium nanoparticles did not elicit a cytotoxic effect after 72 hours (P &lt; 0.01, n = 3). It was found that the IC(50)value was at the ultrahigh concentration of selenium nanoparticles. The nanoparticulate elemental selenium concentration previously shown to decrease the function of bacteria was shown not to cause a cytotoxic effect on fibroblasts in vitro. Conclusion: These findings demonstrate great selectivity between bacteria and healthy cells, and are a viable option for coating endotracheal tubes in order to prevent ventilator-associated pneumonia. 

Retracted: No

PubPeer comments:
 Figure 2 from this paper looks very similar to Figure 2 from an older paper by the same senior author. That paper is Tran PA et al., Inc. J Biomed Mater Res 93A: 1417u20131428, 2010, DOI: 10.1002 jbm.a.32631. In the 2010 paper, Figure 2 represents selenium nanoparticles bound to a titanium surface. In this 2012 paper, Figure 2 represents selenium nanoparticles bound to a polyvinyl chloride surface. Could the authors clarify if these images are representing the same experiment? ![file] , 
 #1 Dr. Bik: I agree that the two images identified appear to represent the same source. I also applaud the Herculean effort that you are making on examining the Webster papers. With dozens of papers containing questionable data now identified here on PubPeer, is it perhaps time for the institutions (and possibly, journals) to conduct their own investigations? I am a bit concerned that there are diminishing returns in you identifying more u201cerrorsu201d in the Webster literature when your services might also be valuable to the world in the COVID-19 papers you have also questioned. , 
 July 30, 2021 The Editor and Publisher of International Journal of Nanomedicine wish to issue an Expression of Concern for the published article. Concerns were raised regarding the alleged duplication of the image shown in Figure 2 with the image shown in Figure 2 in the article Tran et al, 2009 . The International Journal of Nanomedicine would like to alert readers of this while we continue with our investigation. The authors have been contacted and were informed of these concerns. ,