Comparison of cryopreserved amniotic membrane and umbilical cord tissue with dehydrated amniotic membrane/chorion tissue

Objective: To evaluate how the different processing methods cryopreservation and dehydration affect the structural integrity and biological composition of key signalling molecules within amniotic membrane and umbilical cord tissues. Method: We directly compared cryopreserved amniotic membrane (AM) and umbilical cord (UC) tissues with dehydrated amniotic membrane/chorion (dHACM) tissue using biochemical and functional assays including histological and histochemical staining, BCA, agarose gel electrophoresis, western blot, ELISA, and proliferation and cell death assays. Results: Cryopreservation retains the native architecture of the AM/UC extracellular matrix and maintains the quantity and activity of key biological signals present in fresh AM/UC, including high molecular weight hyaluronic acid, heavy chain-HA complex, and pentraxin 3. In contrast, dehydrated tissues were structurally compromised and almost completely lacked these crucial components. Conclusion: The results presented here indicate that cryopreservation better preserves the structural and biological signaling molecules of foetal tissues. Declaration of interest: S.C.G. Tseng and his family are more than 5% shareholders of TissueTech, Inc. TissueTech, Inc. and its Subsidiaries (Bio-Tissue and Amniox Medical) own US Patents Nos. 6,152,142; 6,326,019; and PCT/US2010/046675 on the method of preparation and clinical uses of human amniotic membrane with the CryoTek method distributed by Bio-Tissue, Inc. and Amniox Medical. S.C.G. Tseng, E.K. Tan, and H. He are employees of TissueTech, Inc. J. O'Connell and M. Cooke are employees and shareholders of Amniox Medical. C. Mandrycky has no financial conflict. This research was supported by a Venture Lab Grant #398 from the Georgia Research Alliance, Atlanta, GA, and a research grant from TissueTech, Inc., Miami, FL.