An Algorithm for Determining the Authenticity of Biomedical Cell Preparations Containing Mesenchymal Stem Cells

— The use of mesenchymal stem cells (MSCs) with a pronounced immunomodulatory activity is a promising trend in the development of biomedical cell preparations (BMCPs). In oncohematology, the use of BMCPs containing MSCs is aimed at supporting hematopoiesis after cotransplantation with hematopoietic stem cells (HSC) and suppressing immune conflicts in allogeneic unrelated transplantation and severe autoimmune processes. An obligatory step in BMCP registration consists in confirmation of the MSCs’ authenticity, which includes the establishment of morphological characteristics, the assessment of the expression of specific markers and proteins, and confirmation of the cell genetic stability during cultivation. Determination of genetic-stability markers is possible using various methods; however, according to the recommendations of the American National Standardization Institute, the standard is the analysis of short tandem repeats (STR analysis). The purpose of this study is to develop the algorithm for determining the authenticity of BMCPs containing MSCs including STR analysis. MSCs were identified in BMCPs on the basis of the presence of immunological markers and spindle-cell adhesion to plastic. The number of viable cells was counted with a Goryaev’s chamber. Immunophenotypic characteristics of MSCs were assessed by flow cytometry. The level of production of specific proteins was assayed with enzyme immunoassay. Markers of genetic stability were identified by STR analysis. The methods were tested in triplicate for ten BMCP samples to confirm the reproducibility and reliability of the results. The algorithm developed for determining the BMCP authenticity has a high accuracy, as it includes the STR analysis technique, which makes it possible to identify 19 polymorphic STR markers located on different alleles. Using this method will allow BMCP manufacturers to pass the procedure of state registration of drugs.