Enhancement of Wound Healing and Angiogenesis Using Mouse Embryo Fibroblasts Loaded in Decellularized Skin Scaffold.

Background: Synthetic and natural polymer scaffolds can be used to design wound dressing for repairing the damaged skin tissue. This study investigated acute wound healing process using a decellularized skin scaffold and mouse embryo fibroblast (MEF). Methods: Mouse skin fragments were decellularized and evaluated by DNA content, toxicity, H&E staining, Raman confocal microscopy, Masson's trichrome staining, SEM, and biodegradation assays. The fragments were recellularized by the MEFs, and cell attachment and penetration were studied. De- and decellularized scaffolds were used wound dressings in mouse acute wound models as two experimental groups. Using morphological and immunohistochemical assessments, wound healing was evaluated and compared among the experimental and control groups. Results: DNA content of the decellularized tissue significantly reduced compared to the native control group (7% vs. 100%; p < 0.05). extracellular matrix components, e.g. collagen types I, III, and IV, elastin, and glycosaminoglycan, were well preserved in the decellularized group. The porosity and fiber arrangement in the stroma had a structure similar to normal skin tissue. A significant reduction in healing time was observed in the group treated with a decellularized scaffold. A thicker epidermis layer was observed in the recovered tissue in both experimental groups compared to the control group. Immunostaining showed a positive reaction for CD31 as an endothelial marker in both experimental groups, confirming new vascularization in these groups. Conclusion: Using MEFs with decellularized skin as a wound dressing increases the rate of wound healing and also the formation of new capillaries. This system could be beneficial for clinical applications in the field of tissue engineering.

Deregulation of miR-1, miR486, and let-7a in cytogenetically normal acute myeloid leukemia: association with NPM1 and FLT3 mutation and clinical characteristics.

Cytogenetically normal acute myeloid leukemia (CN-AML) constitutes the largest subgroup of AML patients that is associated with molecular alteration. MiRNAs have been shown to be aberrantly expressed in CN-AML. In addition, specific miRNA (miR) expression patterns were found to be associated with certain genetic alterations in these patients. This study investigated the expression level of miR-1, miR-486, and let-7a in 45 CN-AML patients well characterized for FLT3 and/or NPM1 mutations using real-time quantitative RT-PCR and evaluated the association between candidate miRs expression and clinical features. Our data revealed that miR-1 was significantly overexpressed in CN-AML patients, and increasing expression of miR-1 correlated with NPM1 mutation (P < 0.05) and lower hemoglobin level was also observed in patients with miR-1 overexpression (P < 0.05). The expression of miR-1 was much higher in AML-M2 compared with other subtypes. Further, we found significantly increasing miR-486 expression in 40 of 45 (89 %) CN-AML patients. There was no significant association of upregulation of miR-486 with clinical parameters. The expression level of miR-486 was increased in AML-M2 subtype. The levels of let-7a were significantly increased in CN-AML patients compared to the healthy control and significantly higher in the NPM1 ± CN-AML patients. There was no correlation detected between the level of let-7a and FLT3+. An increasing expression level of let-7a was demonstrated in M2 subtype. In addition, our data showed no significant association between increasing let-7a and clinical characteristic. Comparison of peripheral blood and bone marrow results in 30 CN-AML patients showed that there is a considerable concordance between PB and BM in the results of candidate miR levels (P < 0.001). In conclusion, further studies should also be performed to detect functional mechanism of these miRs.