Study of the viability of cultured human cells in suspensions

The success of cell therapy is directly related to the viability of cells used for transplantation. The cells used for transplantation are in some cases injected in suspension. However, the optimal conditions for the preservation of cell viability upon the preparation and storage of cell suspensions for transplantation have not been defined yet. The aim of the present work consisted in the selection of optimal conditions for the storage of suspensions of human submandibular salivary gland cells, differentiated cells of the submandibular salivary gland, and dermal fibroblasts in biocompatible solutions. Standard procedures of cell isolation and cultivation were used in the study. An automatic cell counter from BioRad was used to count the cells, and viability of the cells was assessed using staining with 4% Trypan Blue. The biocompatible solutions tested included phosphate-buffered saline, physiological saline for injections, and a 2% solution of human albumin in phosphate-buffered saline. The study showed that the human cells under investigation remained viable in suspension at both +4°С and +25°С for at least 24 hours, regardless of the carrier solution used. The highest content of viable cells of the salivary gland (more than 50%) at both temperatures examined was observed when cells were suspended in phosphate-buffered saline. However, the adhesive and proliferative properties of the salivary gland cells were better preserved at +4°С in case of 24 hours of incubation under the conditions described above. Fibroblasts maintained in physiological saline formed a homogeneous single-cell suspension that remained stable for 30 hours at +4°С; virtually no loss of cell viability was observed. The addition of 2% albumin resulted in a decrease of the viability of fibroblasts. Thus, storage and transportation in phosphate- buffered saline at +4°С can be recommended for suspensions of cells of the human submandibular salivary gland, whereas human fibroblast suspensions should be maintained at +4°С in physiological saline.