RESUMEN
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.