Quality evaluation of meshed split-thickness skin grafts stored at 4 °C in isotonic solutions and nutrient media by cell cultures

Objective: Excess split-skin autografts harvested and meshed during burn surgery are often stored at 4 degrees C temporarily for later use. The quality of the stored skin is critical to clinical outcome and needs to be assured. Methods: Meshed split-thickness skin graft (mSSG) stored in saline, Hartmann's solution and two cell culture media, Dulbecco's Modified Eagle Medium (DMEM) and DMEM/Ham F12 (DMEM/F12, 3:1 mixture) were analyzed by trypan blue staining, cell culture and microbiological testing through a 28-day time course for cell viability and microbial contamination. Results: mSSG samples in all groups showed a progressive decrease of cell viability and colony forming efficiency through the time course of storage at 4 inverted perpendicular C. Cell culture media were better than saline and Hartmann's solution in maintaining the viability and growth capability of skin cells. The viability observed by trypan blue staining did not truly reflect the cell growth capacity after storage. mSSG in saline and Hartman's solution retained minimal keratinocyte growth potency after 7 days. mSSG in cell culture media had significant loss of keratinocyte colony growth potency after 7 days and minimal keratinocyte growth after 14 days. Dermal fibroblasts of all groups were less tolerant than keratinocytes to the storage. Microbial contaminations were common in mSSG harvested from burn surgery. Conclusions: Culture media instead of saline or Hartman's solution should be used for temporary storage of mSSG at 4 inverted perpendicular C. The stored mSSS should be used within seven days to have sufficient viable number and cell growth efficiency. After then, the efficacy of stored mSSG as a source of living cells for wound closure could be full of uncertainty due to significant decrease of keratinocyte colony forming efficiency. Precaution should be taken during skin harvest and storage to minimize the risk of sample contamination. Inclusion of antimicrobial agents in storage solution and microbiological testing are advisable to ensure the quality and clinical outcome. Crown Copyright (C) 2012 Published by Elsevier Ltd and ISBI. All rights reserved.