Investigation of the effect of different methods of processing human amniotic membrane medicinal products on protein levels in membrane content

Purpose: This study was aimed to investigate the effects of different storage approaches of the human amniotic membrane by measuring levels of proteins that play important roles in wound healing, antiinflammatory, antimicrobial and antifibrotic properties of amniotic membrane. Material and Methodology: Amniotic membrane was isolated from fresh placentas. Seperated pieces of amniotic membranes were divided into four different groups, as following: (1) freshly stored at 4 ⁰C, (2) frozen at -196 ⁰C, (3) lyophilized and (4) gamma irradiated after lyophilization. Total protein was isolated from membranes in experimental groups and was subjected to ELISA test. One-way ANOVA test was used to compare the data. Findings: The highest amount of total protein was detected in fresh amniotic membrane, while the lowest amount of protein was found in the frozen samples at -196 ⁰C (p<0,05). ELISA test results of EGF, bFGF, TGF-β1, Collagen 1, protein levels were detected in such a manner from high to low in fresh amniotic membrane, cryopreserved, lyophilized and post-lyophilised gamma ray samples, respectively (p<0,05). Collagen 3 level was the highest in fresh amniotic membrane (p<0,05). HGF and VEGFA protein levels were highest in the cryopreserved group, whereas PDGF level was detected highest in the fresh amniotic membrane; however, these differences were not statistically significant (p>0,05 ). Conclusion: Highest protein levels were detected in fresh amniotic membranes. But due to their short shelf life at +4 ⁰C, cryopreserving them was found to have less negative effects on proteins when compared to lyophilisation processes in this study.