Despite advances in cryobiology, the reliable cryopreservation of complex tissues has not yet been achieved. This study evaluates the viability of cryopreserved composite flaps and demonstrates the feasibility of their transplantation. Epigastric flaps were harvested from male Lewis rats. 1.5 M dimethyl sulfoxide (Me2SO) was used as the initial cryoprotectant agent (CPA). Samples were frozen at controlled rate to -140 °C and transferred to liquid nitrogen for at least two weeks. Hematoxylin and eosin (H/E) staining, MTT tetrazolium salt assay, and factor VIII immunostaining were used to evaluate the overall histology, epithelial viability, and vascular endothelial integrity, respectively, of cryopreserved flaps. For the in vivo phase, flaps were isotransplanted to 35 recipient animals, divided into three groups: fresh (n = 10), perfused (n = 8), and cryopreserved (n = 17). Blood vessel patency was assessed via Doppler at 1, 7, and 60 days post-transplantation. For in vitro studies, cryopreserved samples (10/10) retained normal cell architecture and vascular endothelial integrity upon H/E and factor VIII staining. The viability index of cryopreserved composite flap skin (n = 10) was 11.17 ± 2.01, which was not significantly different from fresh controls (n = 10, 12.15 ± 1.32). All transplanted flaps in the fresh and perfusion groups survived with healthy color and hair growth at 60 days after operation. Survival in the cryopreserved group ranged from 2 to 60 days, with a mean of 12 days. These results demonstrate that the long term survival of cryopreserved composite tissue transplants is possible. Further studies are needed to refine protocols for the reliable cryopreservation of composite parts.
|Number of pages||10|
|State||Published - Dec 2007|
Bibliographical noteFunding Information:
This work was supported by University of Kentucky Medical Center Research Grant and American Society for Surgery of the Hand Research Grant.
This work was supported by a University of Kentucky Medical Center Research Grant and an American Society for Surgery of the Hand Basic Science Research Grant. The authors wish to express their appreciation to Dr. Dawei Luo, Dr. Weiping Ding, and Dr. Eric Schadler for their kind help in measuring temperature, calculating CPA perfusion, and statistical counseling.
- Composite tissue allotransplantation
- Dimethyl sulfoxide
- Epigastric flap
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology (all)
- Agricultural and Biological Sciences (all)