Mesenchymal stem (stromal) cells (MSCs) are self-renewing, cultured adult stem cells which secrete a complex set of multiple soluble biologically active molecules such as chemokines, and cytokines, cell adhesion molecules, lipid medi­ators, interleukins (IL), growth factors (GFs), hormones, micro RNAs (miRNAs), long non-coding RNAs (lncRNAs), messenger RNAs (mRNAs), exosomes, as well as microvesicles, the secretome. MSCs of various origin, including adipose-derived stem cells (ASCs), bone marrow derived mesenchymal stem cells (BM-MSCs), human uterine cervical stem cells (hUCESCs), may be good candidates for obtaining secretome-derived products. Different population of MSCs can secret different factors which could have anti-inflammatory, anti-apoptotic, anti-fibrotic activities, a neuroprotective effect, could improve bone, muscle, liver regeneration and wound healing. Therefore, the paracrine activity of condi­tioned medium obtained when cultivating MSCs, due to a plethora of bioactive factors, was assumed to have the most prominent cell-free therapeutic impact and can serve as a better option in the field of regenerative medicine in future.

Structure and synthesis of Erythropoietin: Erythropoietin (EPO) is a glycoprotein hormone. Recombinant Erythropoietin (Epoetin): Human recombinant erythropoietin is characterised as a factor which stimu-lates differentiation and proliferation of erythroid precursor cells, and as a tissue protective factor. Anti-ischemic effects of recombinant Erythropoietin: Erythropoietin is one of the most perspective humoral agents which are involved in the preconditioning phenomenon. Erythropoietin receptors and signal transduction pathways: Erythropoietin effects on cells through their inter-connection with erythropoietin receptors, which triggers complex intracellular signal cascades, such as JAK2/STAT signaling pathway, phosphatidylinositol 3-kinase (PI3K), protein kinase C, mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB signaling pathways. Mechanisms of the effect of Erythropoietin on hematopoietic and non-hematopoietic cells and tissues: In addition to regulation of haemopoiesis, erythropoietin mediates bone formation as it has an effect on hematopoietic stem cells and osteoblastic niche, and this illustrates connection between the processes of haematopoiesis and osteopoiesis which take place in the red bone marrow. The effect of Erythropoietin on mesenchymal stem cells and process of bone tissue formation: Erythropoietin promotes mesenchymal stem cells proliferation, migration and differentiation in osteogenic direction. The evidence of which is expression of bone phenotype by cells under the influence of EPO, including activation of bone specific transcription factors Runx2, osteocalcin and bone sialoprotein. Conclusion: Erythropoietin has a pleiotropic effect on various types of cells and tissues. But the mechanisms which are involved in the process of bone tissue restoration via erythropoietin are still poorly understood.

The potential of atomic force microscopy for estimating geometric characteristics of blood cells is demonstrated. Comparison of hemocyte morphometric characteristics recorded using different scanning...