Fabrication of chitin–chitosan/nano TiO2-composite scaffolds for tissue engineering applications
Authors: V V Divyarani
K P Chennazhi
S V Nair
H Tamura
R Jayakumar
Roshni Ramachandran
Journal: International Journal of Biological Macromolecules (2011)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: chitin-chitosan; nano TiO2; composite scaffolds; bone tissue engineering; SEM
Affiliations: Amrita Institute of Medical Sciences and Research Centre, Amrita Vishwa Vidyapeetham Elamakkara, Kochi 682026, Kerala, India. 

Abstract:  In this study, we prepared chitin-chitosan/nano TiO(2) composite scaffolds using lyophilization technique for bone tissue engineering. The prepared composite scaffold was characterized using SEM, XRD, FTIR and TGA. In addition, swelling, degradation and biomineralization capability of the composite scaffolds were evaluated. The developed composite scaffold showed controlled swelling and degradation when compared to the control scaffold. Cytocompatibility of the scaffold was assessed by MTT assay and cell attachment studies using osteoblast-like cells (MG-63), fibroblast cells (L929) and human mesenchymal stem cells (hMSCs). Results indicated no sign of toxicity and cells were found attached to the pore walls within the scaffolds. These results suggested that the developed composite scaffold possess the prerequisites for tissue engineering scaffolds and it can be used for tissue engineering applications. 

Retracted: No

PubPeer comments:
 There are some unexpected similarities between figures in this paper and another paper by partially overlapping authors, i.e. R. Jayakumar et al. International Journal of Biological Macromolecules (2011), doi: 10.1016 j.ijbiomac.2011.04.020. This paper here studied TiO2 nanoparticles. The other paper studied ZrO2 particles. Yet, some figure look unexpectedly similar. Here is a comparison between Figure 2 of this paper and Figure 1 of the ZrO2 paper. Similar spectra representing different compounds are shown with red and blue boxes. ![file] , 
 Figure 3 of this paper appears to have 2 very similar panels (a and b). In addition, these panels look very similar to a panel in Figure 2 of the ZrO2 paper. Shown with aqua boxes. ![file] , 
 Figure 9 of this paper has two panels, e and f, that appear to show an overlap. The contrast is quite different between these 2 panels, so this might not be immediately visible, but the cells and background smears look very similar. Shown with pink boxes. In addition, panel d of Figure 9 looks very similar to panel d of Figure 6 of the ZrO2 paper. Shown with orange boxes. ![file] , 
 A re-do of Figure 3 of this paper compared to Figure 2 of the ZrO2 paper. ![file] , 
 Some unexpected similarities between figures in this paper and that of another paper by the same group, i.e. Rani et al. Carbohydrate Polymers (2011) - doi: 10.1016 j.carbpol.2010.08.065. See: https: pubpeer.com publications 82D43EBC910010909EFC1525572235 Figure 1 of both papers look very similar. Could the authors explain if these reflect the same experiments? If so, why were identical figures sent to 2 different journals? ![file] , 
 Figure 7 of this Jayakumar paper looks very similar to Figure 4 of the Rani paper mentioned in #5. Here, the graphs appear to represent very different scaffolds. ![file] , 
 Figures 9 and 10 of this Jayakumar paper show panels similar to Figure 6 of the Rani paper mentioned in #5. Here, the graphs appear to represent very different scaffolds. ![file] , 
 Corrigendum published, [15 August 2019] . ------------------------------- In the original manuscript, SEM image of Chitin-Chitosan at lower magnification was inadvertently repeated as Chitin-Chitosan nanoTiO2 (Fig. 3B). Hence, we have re-performed SEM imaging of Chitin-Chitosan nanoTiO2 and new Fig. 3 is given below. ![] In the original manuscript, XRD of the bio-mineralized scaffolds (Fig. 7) were provided incorrectly. The experiment was re-performed and the corrected image is given below. ![] Further, MG-63 cell attachment on the chitin-chitosan scaffold was provided incorrectly (Fig. 9a b). To rectify this, whole experiment of cell attachment was repeated and the corrected Fig. 9 is provided below. ![] The changes in these figures would not affect the overall conclusion of this manuscript. The authors would like to apologise for any inconvenience caused. ,