title: In vivo evaluation of wound bed reaction and graft performance after cold skin graft storage: new targets for skin tissue engineering.
abstract: Surplus harvested skin grafts are routinely stored at 4 to 6°C in saline for several days in plastic surgery. The purpose of this study was to evaluate the influence of storage on human skin graft performance in an in vivo intravital microscopic setting after transplantation. Freshly harvested human full-thickness skin grafts and split-thickness skin grafts (STSGs) after storage of 0, 3, or 7 days in moist saline at 4 to 6°C were transplanted into the modified dorsal skinfold chamber, and intravital microscopy was performed to evaluate vessel morphology and angiogenic change of the wound bed. The chamber tissue was harvested 10 days after transplantation for evaluation of tissue integrity and inflammation (hematoxylin and eosin) as well as for immunohistochemistry (human CD31, murine CD31, Ki67, Tdt-mediated dUTP-biotin nick-end labelling). Intravital microscopy results showed no differences in the host angiogenic response between fresh and preserved grafts. However, STSGs and full-thickness skin grafts exhibited a trend toward different timing and strength in capillary widening and capillary bud formation. Preservation had no influence on graft quality before transplantation, but fresh STSGs showed better quality 10 days after transplantation than 7-day preserved grafts. Proliferation and apoptosis as well as host capillary in-growth and graft capillary degeneration were equal in all groups. These results indicate that cells may activate protective mechanisms under cold conditions, allowing them to maintain function and morphology. However, rewarming may disclose underlying tissue damage. These findings could be translated to a new approach for the design of full-thickness skin substitutes.
authors.affiliation: From the *Division of Plastic and Reconstructive Surgery, Department of Surgery, University Hospital Zurich, Switzerland; †Division of Dermatology, University Hospital Zurich, Switzerland; ‡Clinic for Cardiovascular Surgery, University Hospital Zurich, Switzerland; and §Institute for Experimental Surgery, University of Rostock, Germany.
authors.forename: Alicia
authors.initials: A
authors.lastname: Knapik
authors.forename: Kai
authors.initials: K
authors.lastname: Kornmann
authors.forename: Katrin
authors.initials: K
authors.lastname: Kerl
authors.forename: Maurizio
authors.initials: M
authors.lastname: Calcagni
authors.forename: Christian A
authors.initials: CA
authors.lastname: Schmidt
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vollmar
authors.forename: Pietro
authors.initials: P
authors.lastname: Giovanoli
authors.forename: Nicole
authors.initials: N
authors.lastname: Lindenblatt
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D017209:Apoptosis; D049109:Cell Proliferation; D003080:Cold Temperature; D006085:Graft Survival; D006801:Humans; D007150:Immunohistochemistry; D016513:Mice, SCID; D008833:Microcirculation; D008853:Microscopy; D008875:Middle Aged; D018919:Neovascularization, Physiologic; D012867:Skin / Q000098:blood supply; D016038:Skin Transplantation; D013997:Time Factors; D023822:Tissue Engineering; D014021:Tissue Preservation / Q000379:methods*; D014945:Wound Healing