Effect of continuous pressure on the proliferation of rabbit's bone marrow stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Osteoblasts derived from bone marrow stromal stem cells are the main force of the cells In bone marrow cavity.In the artificial joint replacement cases, their life situation is closely related to conductive pressure of prosthesis.OBJECTIVE: To observe the continuous pressure on the proliferation of rabbit's bone marrow stromal stem cells, and to reveal the biomechanism of continuous pressure causing loosening and sinking of prosthesis and its activity after replacement.DESIGN, TIME AND SE'I-I'ING: A randomized study based on cytology was performed at the Institute of Othorpaedics, the Fourth Military Medical University of Chinese PLA from February 2004 to October 2007.MATERIALS: One New Zealand rabbit aging 1 month and weighing 0.5 kg was used to extract the bone marrow stromal calls.METHODS: The third-passaged bone marrow stromal stem cells were inoculated in seven 24-well culture plates at the density of 1 × 104 cells/well. After 14 hours, cells were adherent completely and cultured in DMEM culture media containing 10% fetal bovine serum. Thereafter, the four culture plates were randomly divided into 4 experimental groups, including control group without any pressure, and continuous pressure (20, 60, and 100 kPa) groups. The continuous pressure was performed for 3 hours every day.MAIN OUTCOME MEASURES: Absorbance was detected at day 1, 3, 5, and 7 after culture using MTT assay.RESULTS: Absorbance of the three pressure groups after 3, 5 and 7 days was significantly lower than the control group (P < 0.01). There was no significant difference in absorbance between 20 kPa continuous pressure group and 60 kPa continuous pressure group on the third day (P >0.05); but the absorbance was significantly higher than 100 kPa continuous pressure group (P < 0.05). On the fifth day, there was significant difference in absorbance between paired continuous pressure groups (P < 0.05),i.e., the higher the continuous pressure was, the lower the absorbance was. On the seventh day, the absorbance of the 100 kPa continuous pressure group was significantly lower than 20 kPa continuous pressure group (P < 0.05).CONCLUSION: Patients with eady post-joint replacement had better not stand on the ground; otherwise, a continuous stress will be caused so as to induce the restrain of bone marrow stromal stem calls in the bone marrow cavity, which is not helpful for bone healing and easily causes subsidence and loosening of prosthesis.