In vivo implantation of a tissue engineered stem cell seeded hemi‐laryngeal replacement maintains airway, phonation, and swallowing in pigs
Authors: M A Birchall
S Janes
C Carvalho
A Varanou Jenkins
P D Sibbons
A Southgate
T Ansari
L Partington
P Herrmann
M Lowdell
Journal: Journal of tissue engineering and regenerative medicine (2019)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: animal model; de-cellularisation; larynx; replacement; stem cells
Affiliations: NPIMR, Harrow, UK., UCL Ear Institute, Royal National Throat Nose and Ear Hospital, London, UK., Department Lungs for Living Research Centre, Division of Medicine, Rayne Building, University College London, London, UK., Department of Haematology, University College London, London, UK.

Abstract:  Laryngeal functional impairment relating to swallowing, vocalisation, and respiration can be life changing and devastating for patients. A tissue engineering approach to regenerating vocal folds would represent a significant advantage over current clinical practice. Porcine hemi-larynx were de-cellularised under negative pressure. The resultant acellular scaffold was seeded with human bone marrow derived mesenchymal stem cells and primary human epithelial cells. Seeded scaffolds were implanted orthotopically into a defect created in the thyroid cartilage in 8 pigs and monitored in vivo for 2 months. In vivo assessments consisted of mucosal brushing and bronchoscopy at 1, 2, 4, and 8 weeks post implantation followed by histological evaluation post termination. The implanted graft had no adverse effect on respiratory function in 6 of the 8 pigs; none of the pigs had problems with swallowing or vocalisation. Six out of the 8 animals survived to the planned termination date; 2 animals were terminated due to mild stenosis and deep tissue abscess formation, respectively. Human epithelial cells from mucosal brushings could only be identified at Weeks 1 and 4. The explanted tissue showed complete epithelialisation of the mucosal surface and the development of rudimentary vocal folds. However, there was no evidence of cartilage remodelling at the relatively early censor point. Single stage partial laryngeal replacement is a safe surgical procedure. Replacement with a tissue engineered laryngeal graft as a single procedure is surgically feasible and results in appropriate mucosal coverage and rudimentary vocal fold development. 

Retracted: No

PubPeer comments:
 Somewhat below the radar, this paper was corrected sometime after publication. This is because, most of Figure 1 was Figure 2 from a paper published slightly earlier. And also because, in a pleasing symmetry, Figure 2 was mostly Figure 1 from said other paper. Regarding this pair of papers, figure sleuths at PubPeer, though a tad late to the party, have been moving fast to make up for lost time. See the images and discussion posted for Ansari et al. 2017 at PubPeer https: pubpeer.com publications 9E123595C9AEBBD512BBF1475796DA ***Executive summary:*** DegMed enthusiasts at the pre-Brexit **Global Research Powerhouse** claimed different surgical procedures in the two papers, despite the blatant image reuse for, er, surgical procedures. Other images were also reused for tissues subjected to different experimental procedures. Earlier PubPeer discussions have already revealed that image reuse is Standard Operating Procedure (SOP) for this crack team of DegMed operatives. A fish rots from the head and **GloRP** managerial jobsworths will do anything to avoid being found out. How well does that work? Anyone for a Boeing? **GloRP** are currently hiding a PhD thesis that might shed light on what went on behind these papers, given that doctoral theses tend to have more detail than the publications in the refereed literature. The hidden thesis: https: discovery.ucl.ac.uk id eprint 1533028 A Figure 1 masquerading as a Figure 2: https: pubpeer.com storage imgur-gE5NhOP.png , 
 #1 If wikipedia is to be believed, scepticism is traditionally considered to be a fundamental part of the scientific method. Some of us (who, admittedly, may not belong to teh majority of those claiming to be scientific researchers) think that this requirement was worked out for well-established reasons. https: en.wikipedia.org wiki Scientific_method *Money quote*: **u201cIt involves careful observation, applying rigorous skepticism about what is observedu201d** This applies to all science and, therefore, reckless DegMed studies reporting ostensibly happily-swallowing, joyfully oinking, cut-throated porkers donu2019t have any automatic exclusion from the scientific process. (Whether or not the entitled protagonists of such activities think they do is not something that we are ever likely to know.) For any rigorous scientific observers who happen by, here are Fig. 1 of Herrmann et al. (subject of this thread) and Fig. 2 of the Ansari et al. paper, as linked above. Overlapping images have not been marked up. Enjoy the challenge of mapping out the multiple figure reuses. Insufficient information has been deployed for the observer to determine whether these casually selected images are not all for the same experimental condition - whether or not this is the case might have been explained in the discussion of the Ansari paper linked to in comment #1 ![image] ,