Preclinical regulatory validation of an engineered diaphragmatic tendon made with amniotic mesenchymal stem cells.
OBJECTIVE
Under a Food and Drug Administration directive, we examined definite long-term safety and efficacy aspects of an engineered diaphragmatic tendon graft as a regulatory prerequisite for clinical trials.


METHODS
Newborn lambs (N = 27) underwent partial diaphragmatic replacement with a Teflon patch, a composite acellular bioprosthesis, or the same bioprosthesis seeded with autologous amniotic mesenchymal stem cells processed under Good Manufacturing Practice guidelines. Multiple safety and efficacy analyses were performed at different time points up to 14 months of age (ovine adulthood).


RESULTS
There was no mortality. None of the blood tests or full body autopsy specimens showed any abnormality. There was a significantly higher failure rate in animals that received an acellular bioprosthetic graft vs an engineered graft, with no significant differences between Teflon and acellular bioprosthetic implants. Tensile strength and total collagen levels were significantly higher in engineered grafts than in acellular bioprosthetic grafts. On histology, lysozyme and myeloperoxidase stainings were unremarkable in all grafts.


CONCLUSIONS
Diaphragmatic repair with a clinically viable autologous tendon engineered with amniotic mesenchymal stem cells leads to improved outcomes when compared with an equivalent acellular bioprosthesis, with no local or systemic adverse effects. Clinical trials of engineered diaphragmatic repair appear practicable within regulatory guidelines.
Department of Surgery, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA.
Christopher G
CG
Turner
Justin D
JD
Klein
Shaun A
SA
Steigman
Myriam
M
Armant
Grace A
GA
Nicksa
David
D
Zurakowski
Jerome
J
Ritz
Dario O
DO
Fauza
D000653:Amniotic Fluid / Q000166:cytology*; D000818:Animals; D001705:Bioprosthesis / Q000592:standards*; D003964:Diaphragm / Q000601:surgery*; D004195:Disease Models, Animal; D005260:Female; D006548:Hernia, Diaphragmatic / Q000601:surgery; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods* / Q000592:standards; D011138:Polytetrafluoroethylene; D011247:Pregnancy; D012756:Sheep; D013710:Tendons / Q000637:transplantation*; D023822:Tissue Engineering / Q000379:methods* / Q000592:standards; D014481:United States; D014486:United States Food and Drug Administration
D011138:Polytetrafluoroethylene