gms | German Medical Science

Questionnaire: A perfusion-mechanical dynamic culture system was utilized to mimic the condition of knee joint. A polyurethane meniscus implant (Actifit^TM) supplied a 3-dimension growing environment for bone marrow stromal cells (BMSC). The objective of this study was to investigate the effect of dynamic culture on the proliferation of BMSC seeded in polyurethane meniscus scaffold.

Methods: 20-80 ml bone marrow aspirates from the iliac crest were collected from 7 donors. Isolation and cultivation of human BMSC were performed according to a modified protocol as previously described. 6×10⁶ cells were seeded into one Actifit^TM scaffold. After 4 hours of incubation, the scaffolds were cultures under different conditions.The scaffolds were harvested for further analysis after 24 hours, 1 week and 2 weeks. Proliferation was investigated using the MTS assay. The total protein concentration was measured with Coomassie Plus Reagent. In addition, light and scanning electron microscope analysis were performed to observe the proliferation and distribution of cells. The data of all groups were compared using one-way ANOVA at each time point, a significance level of 0.05 was used (SPSS 15.0).

Results and Conclusions: MTS assay demonstrated a significant increase in proliferation over time in all groups. In addition, statistical differences were found between the individual groups. Both perfusion and mechanical stimulation enhanced the proliferation of BMSC compared with static control. There was no significant difference between the two dynamic culture groups. Similar result was observed from the total protein concentration assay. Light microscope and SEM analysis shown the cells distributed throughout the entire scaffold after incubation for 24 hours. After one and two weeks of static and dynamic culture, cells were observed growing through the pores within the scaffolds, spreading uniformly and extensively (Figure 1 [Fig. 1], Table 1 [Tab. 1]).

In this study, the axial displacement about 800 µm was imposed on the constructs. The compressive strain experienced under this loading condition was 10%, which mimics the reported 10% compressive strain for a native meniscus in vivo. A perfusion rate of 10 ml/min was applied according to our previous experience in 3-dimensional cell culture system. The results shown perfusion culture condition can enhance the proliferation of BMSC cultured in polyurethane scaffolds compared with static control. In addition, the mode of mechanical stimulation had no negative effect on the cell proliferation. These are promising results indeed. Further research about this mechanical stimulation on the differentiation of BMSC should be done. Hopefully, we can construct an ideal tissue-engineered meniscus in this way.