Increased endothelial and vascular smooth muscle cell adhesion on nanostructured titanium and CoCrMo
Authors: Karen M Haberstroh
Mikal Berhe
Saba Choudhary
Thomas J Webster
Journal: International Journal of Nanomedicine (2006)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: vascular cells; nanostructured surface features; vascular stents; endothelial cells; vascular smooth muscle cells
Affiliations: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.

Abstract:  In the body, vascular cells continuously interact with tissues that possess nanostructured surface features due to the presence of proteins (such as collagen and elastin) embedded in the vascular wall. Despite this fact, vascular stents intended to restore blood flow do not have nanoscale surface features but rather are smooth at the nanoscale. As the first step towards creating the next generation of vascular stent materials, the objective of this in vitro study was to investigate vascular cell (specifically, endothelial, and vascular smooth muscle cell) adhesion on nanostructured compared with conventional commercially pure (cp) Ti and CoCrMo. Nanostructured cp Ti and CoCrMo compacts were created by separately utilizing either constituent cp Ti or CoCrMo nanoparticles as opposed to conventional micron-sized particles. Results of this study showed for the first time increased endothelial and vascular smooth muscle cell adhesion on nanostructured compared with conventional cp Ti and CoCrMo after 4 hours' adhesion. Moreover, compared with their respective conventional counterparts, the ratio of endothelial to vascular smooth muscle cells increased on nanostructured cp Ti and CoCrMo. In addition, endothelial and vascular smooth muscle cells had a better spread morphology on the nanostructured metals compared with conventional metals. Overall, vascular cell adhesion was better on CoCrMo than on cp Ti. Results of surface characterization studies demonstrated similar chemistry but significantly greater root-mean-square (rms) surface roughness as measured by atomic force microscopy (AFM) for nanostructured compared with respective conventional metals. For these reasons, results from the present in vitro study provided evidence that vascular stents composed of nanometer compared with micron-sized metal particles (specifically, either cp Ti or CoCrMo) may invoke cellular responses promising for improved vascular stent applications. 

Retracted: No

PubPeer comments:
 Images and table data from this paper appear to also be shown in two later papers by one of that authors, without a clear mentioning that these data have been published before. The three papers with similar images are: * Thomas J. Webster, Jeremiah U. Ejiofor - Increased osteoblast adhesion on nanophase metals: Ti, Ti6Al4V, and CoCrMo - Biomaterials 25 (2004) 4731u20134739 - DOI: 10.1016 j.biomaterials.2003.12.002 ( Webster 2004 ) * Saba Choudhary , Mikal Berhe , Karen M Haberstroh , Thomas J Webster - Increased endothelial and vascular smooth muscle cell adhesion on nanostructured titanium and CoCrMo - International Journal of Nanomedicine 2006:1(1) 41u201349 - DOI: 10.2147 nano.2006.1.1.41 ( Choudhary 2006 , this paper) * Saba Choudhary, Karen M. Haberstroh, Thomas J. Webster - Enhanced Functions of Vascular Cells on Nanostructured Ti for Improved Stent Applications - Tissue Engineering (2007) - DOI: 10.1089 ten.2006.0376 ( Choudhary 2007 ) Here is a comparison of figures from these three papers, with panels that look similar marked with boxes of the same color. The panels might be showing the same materials, but there is no mention that these figures had been published before.  , 
 Table data in these three papers also appears to share some similarities. Of note, the standard errors appear to be different between the 2006 and 2007 papers, although the mean values are the same. Could the authors clarify if the same measurements were published twice, or if these were different experiments?  ,