Yu. A. Petrenko

Cryopreservation of human fetal liver hematopoietic stem/progenitor cells using sucrose as an additive to the cryoprotective medium

INTRODUCTION Human fetal liver (HFL) is a valuable source of hematopoietic stem/progenitor cells (HSCs) for the treatment of various hematological disorders. This study describes the effect of sucrose addition to a cryoprotective medium in order to reduce the Me(2)SO concentration during cryopreservation of HFL hematopoietic cell preparations. METHODS Human fetal liver (HFL) cells of 8-12 weeks of gestation were cryopreserved with a cooling rate of 1 degrees C/min down to -80 degrees C and stored in liquid nitrogen. The cryoprotectant solutions contained 2% or 5% Me(2)SO (v/v) with or without sucrose at a final concentration of 0.05, 0.1, 0.2 or 0.3M. The metabolic activity of HFL cells was determined using the alamar blue assay. For the determination of the number and survival of hematopoietic progenitors present, cells were stained with CD34 (FITC) and 7-AAD, and analyzed by flow cytometry. The colony-forming activity of HFL hematopoietic stem/progenitor cells after cryopreservation was assessed in semisolid methylcellulose. RESULTS The addition of sucrose to the cryoprotective medium produced a significant reduction in HFL cell loss during cryopreservation. The metabolic activity of HFL cells, cryopreserved with 5% Me(2)SO/0.3M sucrose mixture was comparable to cryopreservation in 5% Me(2)SO/10% FCS. Although the inclusion of sucrose did not affect the survival of CD34(+) cells in HFL after cryopreservation it did improve the functional capacity of hematopoietic stem/progenitor cells. CONCLUSION The inclusion of sucrose as an additive to cryoprotective media for HFL cells enables a reduction in the concentration of Me(2)SO, replacing serum and increasing the efficiency of cryopreservation.

Comparison of the methods for seeding human bone marrow mesenchymal stem cells to macroporous alginate cryogel carriers

We performed a comparative study of the localization, distribution, metabolic activity, and surface properties of human bone marrow mesenchymal stromal cells after static and perfusion seeding to macroporous alginate cryogels. A simple perfusion system for mesenchymal stromal cell seeding to macroporous alginate cryogel sponges proposed in this study resulted in rapid and uniform distribution of cells within the whole volume of the scaffold preserving functional and morphological properties of the cells.

Growth and adipogenic differentiation of mesenchymal stromal bone marrow cells during culturing in 3D macroporous agarose cryogel sponges

We studied the possibility of population of macroporous agarose cryogel sponges by mesenchymal stromal bone marrow cells with their subsequent adipogenic differentiation. After 7-day culturing of mesenchymal stromal cells in agarose cryogel, the level of cell proliferation was 35%. After 3-week culturing in a medium inducing adipogenesis we observed accumulation of intracellular neutral lipids positively stained with Oil Red O. These findings can be used for the development of bioengineering constructions of the adipose tissue on the basis of spongy carriers.

Phenotypical properties and ability to multilineage differentiation of adipose tissue stromal cells during subculturing

Morphological and immunophenotypical properties of human adult adipose tissue stromal cells (ATSC) at cultivation passage 0 and 4 as well as their ability to induced in vitro differentiation into adipogenic and osteogenic directions were studied in this work. It was shown that primary cultures of ATSC were characterized by the presence of the lower number of cells expressing mesenchymal markers (CD73, CD105) than the cells of the 4th passage, but contained endothelial progenitor cells expressing CD34 and capable to form capillary-like structures within extracellular matrix. Both cell populations could equally differentiate into adipogenic and osteogenic lineages.

The Use of Catalytic Carbon Deposits as 3D Carriers for Human Bone Marrow Stromal Cells

We studied the possibility of using 3D structures based on carbon catalytic deposits as carriers for human bone marrow stromal cells. It was found that carbon catalytic deposits obtained by gas deposition method using FeCl3 × 6H2O as the catalyst are a biocompatible material for human bone marrow stromal cells promoting adhesion, proliferation, and distribution of cells within the 3D carrier, and therefore can be used for tissue engineering.