A new model for preclinical testing of dermal substitutes for human skin reconstruction.
BACKGROUND
Currently, acellular dermal substitutes used for skin reconstruction are usually covered with split-thickness skin grafts. The goal of this study was to develop an animal model in which such dermal substitutes can be tested under standardized conditions using a bioengineered dermo-epidermal skin graft for coverage.


METHODS
Bioengineered grafts consisting of collagen type I hydrogels with incorporated human fibroblasts and human keratinocytes seeded on these gels were produced. Two different dermal substitutes, namely Matriderm(®), and an acellular collagen type I hydrogel, were applied onto full-thickness skin wounds created on the back of immuno-incompetent rats. As control, no dermal substitute was used. As coverage for the dermal substitutes either the bioengineered grafts were used, or, as controls, human split-thickness skin or neonatal rat epidermis were used. Grafts were excised 21 days post-transplantation. Histology and immunofluorescence was performed to investigate survival, epidermis formation, and vascularization of the grafts.


RESULTS
The bioengineered grafts survived on all tested dermal substitutes. Epidermis formation and vascularization were comparable to the controls.


CONCLUSIONS
We could successfully use human bioengineered grafts to test different dermal substitutes. This novel model can be used to investigate newly designed dermal substitutes in detail and in a standardized way.
Tissue Biology Research Unit, Department of Surgery, University Children's Hospital Zurich, Zurich, Switzerland.
Fabienne
F
Hartmann-Fritsch
Thomas
T
Biedermann
Erik
E
Braziulis
Martin
M
Meuli
Ernst
E
Reichmann
D000818:Animals; D057005:Bioengineering; D003094:Collagen / Q000627:therapeutic use*; D024042:Collagen Type I; D004549:Elastin / Q000627:therapeutic use*; D006085:Graft Survival; D006801:Humans; D020100:Hydrogels / Q000627:therapeutic use*; D023421:Models, Animal; D051381:Rats; D011919:Rats, Inbred Strains; D017768:Skin, Artificial
D024042:Collagen Type I; D020100:Hydrogels; C532298:matriderm; D003094:Collagen; D004549:Elastin