Antimicrobial Efficacy Assessment of Allogenic Amnion-Chorion Membrane

Objectives: The human derived composite amnion-chorion membrane (ACM) has been clinically used to facilitate wound healing because it can control inflammation and promote cell proliferation. Its antimicrobial property is not well evaluated although it is known that human placental tissues have antimicrobial properties. This study was aimed to evaluate the antimicrobial efficacy of ACM using novel assays to visualize and quantitate bacterial growth on membranes.
Methods: Both ACMs (test) and Porcine Pericardium Collagen Membranes (PPCMs; control) were assessed. Bacterial cells, Streptococcus gordonii, Prevotella intermedia and Porphyromonas gingivalis, were grown into the log phase for conducting the two novel antimicrobial efficacy assays designed to assess the direct growth of bacteria on the membrane. The insert assay had membranes placed in the cell culture inserts and submerged under culture medium. The agar contact assay had membranes placed in the culture plates and supported by agar. Bacterial cells (S. gordonii, P. intermedia, and P. gingivalis) were spotted onto the membranes and then the plates were centrifuged to ensure direct bacterial contact with the membranes. After incubation at 37⁰C for 8, 24, and 48 hours, the membranes were stained with Live/Dead BacLight Bacterial Viability kit and analyzed via confocal microscopy. Each time point had three membranes processed for the analysis.
Results: In the insert and agar contact assays, the images clearly demonstrated that none of the bacterial cells survived on the ACM at all time points, whereas the PPCM did not show any antimicrobial properties. Therefore, the statistical analysis was not performed.
Conclusions: Within the limits of this study, ACM showed extremely high antimicrobial efficacy of oral bacterial species. The two novel assays could be used to objectively quantify antimicrobial efficacy of membranes directly contacted with oral bacterial species at different time points.