Methods for assessing the quality of biomedical cell products for skin replacement

Abstract

The aim of the study was the development of methods to assess the quality of biomedical cell products (BMCPs) intended to replace skin defects. Materials and Methods. The proposed equivalent of the skin BMCP-1 (developed at the N.K. Koltsov Institute of Developmental Biology, Russian Academy of Sciences) and the BMCP-2 equivalent of the skin (developed at the Privolzhsky Research Medical University) were studied. Mesenchymal stem cells (MSCs) from human adipose tissue served as the cellular components of both BMCPs. MSCs in suspensions and in BMCPs were tested for cell counts and cell viability. The BMCPs were studied in their entirety without destruction using fluorescence microscopy with vital dyes for staining the cytoplasm and Hoechst 3334 (BD Pharmingen, USA) — for nuclei (imager Cytation 5; BioTek, USA). The MSC function was evaluated by their ability to produce VEGF-A. The MSC phenotype was determined by cytometry. Results. Using the above methods, we found that MSCs in BMCP retained their original morphology and viability. On the surface of BMCP-1, cells are organized in colonies, whereas in the structure of BMCP-2, they are scattered throughout the matrix. The number of cells in BMCP-1 depends on the transportation conditions; and in the structure of BMCP-2 — on the timing of cultivation. The secretory activity of MSCs is maintained throughout the entire observation period. While within the BMPC structures, the MSCs had their CD90 expression decreased; it was then restored after the cells were isolated from the products and cultivated on the plastic surface. Conclusion. The proposed method is feasible for the BMCP quality assessment; it incorporates the requirements for production and transportation based on the characteristics of the cellular and non-cellular components. Given the optical non-transparency and complex physical-chemical structure of the product, it is advisable to select the quality control methods that ensure minimal manipulation and enzymatic damage.