Integrin-mediated osteoblastic adhesion on a porous manganese-incorporated TiO coating prepared by plasma electrolytic oxidation
Authors: Zhenxiang Zhang
Lixian Zhu
Wei Zhu
Beibei Gu
Journal: Experimental and Therapeutic Medicine (2013)
Discipline: CLINICAL MEDICINE
Keywords: MG63; TiO2; adhesion; manganese; plasma electrolytic oxidation.
Affiliations: Orthopedic Department, The Affiliated Taizhou People's Hospital of Nantong University, Taizhou, Jiangsu 225300, P.R. China.

Abstract:  This study was conducted to evaluate the bioactivity of manganese-incorporated TiO2 (Mn-TiO2) coating prepared on titanium (Ti) plate by plasma electrolytic oxidation (PEO) technique in Ca-, P- and Mn-containing electrolytes. The surface topography, phase and element compositions of the coatings were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometry (EDS), respectively. The adhesion of osteoblast-like MG63 cells onto Ti, TiO2 and Mn-TiO2 surfaces was evaluated, and the signal transduction pathway involved was confirmed by the sequential expression of the genes for integrins β1, β3, α1 and α3, focal adhesion kinase (FAK), and the extracellular regulated kinases (ERKs), including ERK1 and ERK2. The results obtained indicated that Mn was successfully incorporated into the porous nanostructured TiO2 coating, and did not alter the surface topography or the phase composition of the coating. The adhesion of the MG63 cells onto the Mn-incorporated TiO2 coating was significantly enhanced compared with that on the Mn-free TiO2 coating and the pure Ti plates. In addition, the enhanced cell adhesion on the Mn-TiO2 coatings may have been mediated by the binding of the integrin subunits, β1 and α1, and the subsequent signal transduction pathway, involving FAK and ERK2. The study indicated that the novel Mn-TiO2 coating has potential for orthopedic implant applications, and that further investigations are required. 

Retracted: No

PubPeer comments:
 *[above]* Fig 1.  Surface morphologies of the (A and C) titanium dioxide (TiO2) and **(B and D) manganese (Mn)-incorporated-TiO2 coatings** at different magnifications (A and B; magnification, x1,000; bar=5 u00b5m... *[below]* Fig. 1 from [Zhu et al (2013)] .  Surface morphologies of the TiO2 (a) and (c), and **Cu-TiO2 (b)** and (d) coatings at different magnifications. ![file] Overlap between Mn-TiO2 and Cu-TiO2. -------------------------------------------- *[above] Fig 1, panels  C and D; magnification, x50,000; bar=100 nm . *[below]* Fig 1 from [Zhang (2015)] .  Surface micrographs of polished TiO2 (a,c) and **Sr-TiO2**(b,d) (bar=10 u03bcm for a,b; bar=100 nm for c, d). ![file] , 
 *[left]* Fig. 8.  MG63 cells proliferated for 2 or 5 days on **Ti plates (a)** and (d), TiO2 coatings (b) and (e) and CueTiO2 coatings (c) and (f) ((a)e(c) 2 days and (d)e(f) 5 days). *[right]* Figure 5 from [Zhang (2015)] .  Acridine orange staining assay of cells cultured for 5 and 10 h on Ti plates(a,d) ,TiO2 coatings (b,e) and **Sr- TiO2 (c**,f). (a,b,c for 5 h; d,e,f for 10 h). ![file] The second paper was published in  Journal of Clinical Experimental Orthopaedics from  iMedPub , a polyp or extrusion of the predatory publisher OMICS. More comparisons with the present paper are possible but I feel dirty enough already. , 
 *[right]* Fig 6.  Scanning electron microscopy micrographs exhibiting the morphology of MG63 cells cultured for 16 h on (A) titanium plates, and with (B) titanium dioxide (TiO2) and (C) manganese (Mn)-incorporated-TiO2 coatings . *[left]* Fig 8 from [Zhang et al (2011)] , with rotated versions of panels (c) and (e). Red and blue boxes mark overlaps. ![] ,