Biological characteristics of human bone marrow-derived mesenchymal stem cells at different passages: Third to sixth passages are recommended for clinical application / 中国组织工程研究

ABSTRACT

BACKGROUND: Mesenchymal stem cells are few in human bone marrow, and their number will decrease with aging or body weakening, so a large amount of amplification is necessary. However, the biological characteristics of human mesenchymal stem cells of each passage remain poorly understood.OBJECTIVE: To analyze and compare the biological characteristics of each passage of bone marrow-derived mesenchymal stem cells (MSCs) so as to provide a basis for clinical demands of tissue engineering.DESIGN,TIME AND SETTING: Cytological observation in vitro. The experiment was performed at the Department of Orthopedics and Central Laboratory, Dongzhimen Hospital, Beijing University of Chinese Medicine from March to October 2008.MATERIALS From bone marrow of patients with non-hematopoietic disease, MSCs were provided by Department of Orthopedics, Dongzhimen Hospital, Beijing University of Chinese Medicine.METHODS: Bone marrow was collected form posterior superior iliac spine of patient, MSCs were isolated and cultured by Percoll method. When the cells were confluent at 90%, they were trypsinized and observed by inverted miscroscopy. The second passage of cells were collected for index detection.MAIN OUTCOME MEASURES: Cell morphological characteristics and immunophenotype; cell activity was detected by MTT; cell division and apoptosis in the proportion of necrosis were analyzed by flow cytometry analysis.RESULTS: The passaged MSCs exhibited uniform appearance in fusiform shape, and their growth was slowed down after 9 passages, exhibiting cytoplasm vacuolization and body enlarging. The second passage of MSCs was positive for CD44, CD106,and CD105, but negative for CD34 and CD45. MTT values peaked at passage 9, and gradually decreased since passage 10. At passage 11, the number of MSCs at division stage was increased, but from the sixth passage, the number of apoptotic cells increased significantly, reaching more than 60% at passage 8.CONCLUSION: According to biological characteristics analysis of MSCs at each passage, the third to the sixth passage cells are recommend for clinical therapy.