Questions about Residual Cell Viability in Cryopreserved Human Amniotic Membrane and Its Impact on Clinical Applications

Abstract

We questioned the relevance of evaluating residual cell viability in human amniotic membrane (hAM) after its cryopreservation since cell survival is controversial and its ability to act as a matrix (including the presence of growth factors and cytokines) appears to be most important for tissue regeneration purposes. We also discussed the usefulness of osteodifferentiating amniotic cells in whole hAM for bone repair applications. We have evidence that determining residual cell viability after cryopreservation and hAM osteodifferentiation is not justified.

Histological Assessment of Bone Regeneration in the Maxilla with Homologous Bone Graft: A Feasible Option for Maxillary Bone Reconstruction

“…Depending on the tissue volume used for reconstruction, the entire healing process will last months. Moreover, it can be slower in homologous than in autologous bone grafts, likely due to a low residual immunological discrepancy or cell viability [30] and lack of osteoinduction and osteogenesis capacity. Furthermore, it is important to highlight that block-type autogenous bone is still considered the gold standard biomaterial for reconstruction.…”

Preparation of human amniotic membrane for transplantation in different application areas

“…Some authors seem to use it to refer to the remaining activity in the sense of the effectiveness of the hAM rather than referring to living cells. At the same time, studies show that vital cells do not necessarily need to be present for effectiveness of the treatment ( 86 ) unless a high factor content is essential, as living cells continue to produce proteins after transplantation ( 85 ).…”

“…For example, the preparation method affects the angiogenic factor (AF) profile via the cell vitality ( 81 ). Nevertheless, the relevance of vital cells for clinical outcome has not yet been clarified ( 86 ). The multitude of published positive healing results achieved with material in which no living cells were present show that, as a rule, the vitality of the cells does not play a decisive role.…”

“…Other therapeutic options in this area include the management of medication-related osteonecrosis of the jaw ( 162 – 164 ) and mucosal defects, root coverage of gingival recession, and oronasal fistulae management ( 86 ).…”