In vitro interaction of human Wharton's jelly mesenchymal stem cells with biomimetic 3D scaffold

Study of cell-biomaterial interaction is a crucial aspect of bone tissue engineering to find a state-of-the-art functional substitute. In present study, the Wharton's jelly mesenchymal stem cells (hWJ-MSCs) behavior on three-dimensional biomimetic nano-hydroxyapatite/chitosan/gelatin (nHA/CS/Gel) scaffolds was investigated. The outcome was assessed by histological, biochemical and morphological tests. Results indicated that hWJ-MSCs attached onto the scaffold surface through membrane filopodia, uniformly spread throughout the contacting surface. It only took 3 days for the seeded cells to appear deep inside the scaffold, reflecting proper hWJ-MSCs adhesion and migration, evidenced by both scanning electron microscope and hematoxilin and eosin assessments. Additionally, the present fabricated nHA/CS/Gel scaffold proved to be non-toxic as it supported cell proliferation measured by 3-(4,5-dimethylthiazoyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Moreover, 3-week culture of hWJ-MSCs on scaffolds, immersed in osteogenic medium, rendered the microenvironment in favor of hWJ-MSCs differentiation into osteoblast cells and extracellular matrix secretion. Finally, osteoblasts were immunologically positive for various osteogenic markers including osteocalcin, osteopontin, osteonectin, and alkaline phosphatase. Present findings indicate that nHA/CS/Gel scaffold appropriately harbored hWJ-MSCs, stimulating their growth, migration, proliferation, and differentiation. hWJ-MSCs-loaded nHA/CS/gel substitute may therefore be considered as a suitable platform for the rising demand in in vivo bone repair studies. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1166�1175, 2019. © 2019 Wiley Periodicals, Inc

In vitro antibacterial property assessment of silver nanoparticles synthesized by Falcaria vulgaris aqueous extract against MDR bacteria

Silver nanoparticles (AgNPs) were fabricated in the presence of Falcaria vulgaris aqueous extract as a biosynthesis method without utilizing any surfactant or template. AgNPs were prepared under different synthesis conditions such as silver ion concentration and the amount of plant used for the extraction, reaction duration and temperature for the extraction. The effect of these variables on the size of resulted AgNPs was examined, and operation conditions were optimized statistically with analysis of variance (ANOVA) to describe the role of these variables in tuning the size of AgNPs. The results of ANOVA displayed the optimum conditions for the synthesis procedure that resulted in AgNPs with the average size of 28 ± 8 nm. Furthermore, the growth of AgNPs was monitored by UV-Vis spectroscopy, and they were characterized using TEM, SEM, X-ray diffraction, and FT-IR spectroscopy. Finally, in vitro antibacterial activity of the AgNPs showed the maximum inhibition zone alongside Staphylococcus aureus (ATCC 25923) and lowermost inhibition zone touching E. coli (MDR). The minimum inhibitory concentration (MIC) for the AgNP-Fv was in a range between 0.535 and 0.001 µg/ml. According to the results, the ATCC bacteria were more sensitive to AgNP-Fv compared to multiple-drug resistance bacteria, except for Pseudomonas aeruginosa (MDR). Figure not available: see fulltext.. © 2019, Springer Science+Business Media, LLC, part of Springer Nature