RESULTS: In this work, we report the molecular characterization of an actinomycetes, isolated from tropical freshwater wetlands sediments, that demonstrated rapid aerobic extracellular reduction of ferric ions to generate iron based nanoparticles. Characterization of these nanoparticles was carried out using Field Emission Scanning Electron Microscope with energy dispersive X-ray spectroscopy (FESEM-EDX), Field Emission Transmission Electron Microscope (FETEM), Ultraviolet-Visible (UV-Vis) Spectrophotometer, dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). This process was carried out at room temperature and humidity and under aerobic conditions and could be developed as an environmental friendly, cost effective bioprocess for the production of IONP's.
CONCLUSION: While it is undeniable that iron reducing microorganisms confer a largely untapped resource as potent nanofactories, these bioprocesses are largely anaerobic and hampered by the low reaction rates, highly stringent microbial cultural conditions and polydispersed nanostructures. In this work, the novel isolate demonstrated rapid, aerobic reduction of ferric ions in its extracellular matrix, resulting in IONPs of relatively narrow size distribution which are easily extracted and purified without the need for convoluted procedures. It is therefore hoped that this isolate could be potentially developed as an effective nanofactory in the future.
MATERIALS AND METHODS: This was a cross-sectional study, involving a total of 100 cases that comprised of acute subchorionitis (stage I, n=20), acute chorioamnionitis (stage II, n=20), acute necrotising chorioamnionitis (stage III, n=20) and non-chorioamnionitis placenta as control (n=40). All tissue blocks were retrieved from the archived pathology record over a period of 4 years. CD36 and CD47 immunohistochemistry were performed on all cases and their expression in various cell types on the placenta were analysed.
RESULTS: CD36 was expressed only on the foetal vascular endothelial cells. Interestingly, CD47 showed positive staining on the neutrophils and its expression was significantly different between maternal inflammatory response stage II chorioamnionitis (n=13/20, p<0.001) with stage I and stage III chorioamnionitis.
DISCUSSION: Our study showed CD47 was expressed in the neutrophils and it was associated with poorer perinatal outcomes and it may have a role in the pathogenesis of chorioamnionitis.