Dehydration and devitalization - tissue altered, viable cells not preserved
Most placental tissue products are devitalized, meaning that the living cells are killed during preservation, usually by dehydration or conventional lyophilization techniques
Dehydration via heat drying is one of the most common techniques
Blood components are carefully removed from donated tissue leaving an intact extracellular matrix. The graft is then dehydrated under controlled drying conditions, a simple way to ensure placental tissue is safe to use and has a practical shelf life.
However, dehydration dramatically impacts the structure of the tissue
Studies have demonstrated that dehydration is a harsh method. It not only devitalizes the tissue but also results in protein denaturation, plus a thinned ECM with damage to the structural and mechanical properties of the tissue.
Sterilization techniques, such as gamma and electron beam irradiation, are often used in conjunction with dehydration and have also been shown to damage key proteins of the basement membrane, such as elastin and collagen fibers.
- Banerjee J, Dhall S. Therapeutic benefits of treating chronic diabetic wounds with placental membrane allografts. In: Bagchi D, Das A, Roy S, eds. Wound Healing, Tissue Repair and Regeneration. Academic Press, Cambridge, MA, USA 2020:323–335.
- Cooke M, Tan EK, Mandrycky C, He H, O’Connel J, Tsend SC. Comparison of cryopreserved amniotic membrane and umbilical cord tissue with dehydrated amniotic membrane/chorion tissue. J Wound Care. 2014;23(10):465–474.
- Johnson A, Gyurdieva A, Dhall S, Danilkovitch A, Duan-Arnold L. Understanding the impact of preservation methods on the integrity and functionality of placental allografts. Ann Plast Surg. 2017;79(2):203–213.