Development of a simple, repeatable, and cost-effective extracellular matrix for long-term xeno-free and feeder-free self-renewal of human pluripotent stem cells
Authors: Mohammad Kazemi Ashtiani
Hossein Baharvand
Seyed Latif Mousavi-Gargari
Mohammad Pakzad
Journal: Histochemistry and Cell Biology (2013)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: human pluripotent stem cells; extracellular matrix; RoGel; self-renewal; pluripotency
Affiliations: Department of Stem Cells and Developmental Biology at Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran.

Abstract:  Given the potential importance of human pluripotent stem cells (hPSCs) in translational research and regenerative medicine, the aim of the present study was to develop a simple, safe, and cost-effective substrate to expand hPSCs. We report the development of an extracellular matrix (ECM), designated "RoGel," based on conditioned medium (CM) of human fibroblasts under serum- and xeno-free culture conditions. The long-term self-renewal of hPSCs on RoGel was also assessed. The results showed that self-renewal, pluripotency, plating efficiency, and cloning efficiency of hPSCs on this newly developed ECM were similar to those of Matrigel, the conventional mouse-cell line-derived ECM. The cells had the capability to passage mechanically on a cold surface, which resulted in their long-term maintenance with normal karyotype. We have demonstrated that CM-coated plates preserved for 1 year at room temperature maintained the capability of hPSC expansion. This ECM provides an attractive hPSC culture platform for both research and future therapeutic applications. 

Retracted: No

PubPeer comments:
 The authors state they have no conflict of interest to declare.  Yet, this paper appears to contain a lot of overlap with US Patent application US20140220680A1, which can be found here: https: patents.google.com patent US20140220680A1 The inventors of the patent are Hossein Baharvand and Mohammad Pakzad, both authors of this paper, and the patent was filed by Royan Research, presumably associated with the Royan Institute with which the authors are affiliated. Many images in the patent are identical to those in the paper. The patent is based on a provisional application Ser. No. 61 676,900, filed Jul. 28, 2012. The patent itself was filed in February 2013, and granted in August 2014. This paper was accepted on August 14, 2013, so much later than the initial patent application. Could the authors please comment why they did not see this patent as a potential conflict of interest?  , 
 Dear Dr. Bik, Thank you so much for your analysis of my articles! Currently, we are carefully checking each of your comments and concerns regarding  image concerns and undisclosed conflict of interest in some of my papers. We have also started to contact the related journals to ask for corrective notes on those articles that need correction or other potential actions. We will update, on Pubpeer, the final changes and actions communicated with the journals once we get feedback from the journals. Thank you again for your time and concern! Sincerely yours, Hossein Baharvand , 
 #1 Thank you for your concern. We have explained to the editor and asked to publish an Erratum to our manuscript to avoid any potential ambiguities in the future and they accepted. , 
 Correction, January 2021: https: link.springer.com article 10.1007 s00418-021-01963-4  After publication of our article, it has come to our attention that our Conflict of Interest statement should read: u2018A patent on the developed matrix has been filed by the Royan Institute with Hossein Baharvand and Mohammad Pakzad as inventorsu2019. I thank the authors, journal editors, and publisher staff for correcting the record. ,