[Experimental study of the effects of fluid dynamics on the construction of large-scale tissue engineered bone].
OBJECTIVE
To investigate the effects of flow shear stress and mass transport on the construction of large-scale tissue engineered bone using a perfusion bioreactor.


METHODS
Bone marrow (20 mL) was harvested from the iliac crest of the healthy volunteer, and then hBMSCs were isolated, cultured and identified. The hBMSCs at passage 3 were seeded on the critical-size beta-TCP scaffold and cultured in a perfusion bioreactor for 28 days. Different flow shear stress (1 x, 2 x and 3 x) and different mass transport (3, 6 and 9 mL/min) were exerted on the cells seeded on the scaffold by changing the viscosity of media or perfusion flow rate. The cell proliferation and ALP activity of cells seeded on the scaffold were detected, and histology observation and morphology measurement of cell/scaffold complex were conducted.


RESULTS
When the perfusion flow rabe was 3 mL/min, the cell viability of 2 x group was higher than that of other groups (P < 0.05). When the flow shear stress was 3 x, no significant differences were found among 3, 6 and 9 mL/min in cell viability (P > 0.05). When the perfusion flow rate was 3 mL/min, the activity of ALP of 2 x and 3 x groups was higher than that of 1 x group (P < 0.05). When the flow shear stress was 3 x, the activity of ALP of 6 mL/min group was the highest (P < 0.05). After 28 days of perfusion culture, the ECM of all the groups distributed throughout the scaffold, and the formation and mineralization of ECM was improved with the increase of flow shear stress when the perfusion flow rate was 3 mL/min. However, the increase of perfusion flow rate decreased the mineralization of ECM when the flow shear stress was 3 x.


CONCLUSIONS
As two important fluid dynamics parameters affecting the construction of large-scale tissue engineered bone, the flow shear stress and the mass transport should be measured during the process of constructing large-scale tissue engineered bone so as to maximize their roles.
Department of Orthopaedics, Shanghai Institutes for Biological Sciences, the Ninth People's Hospital, Medical College of Shanghai Jiaotong University, Shanghai, PR China.
Deqiang
D
Li
Kerong
K
Dai
Tingting
T
Tang
Jianxi
J
Lu
D001672:Biocompatible Materials; D019149:Bioreactors; D001854:Bone Marrow Cells / Q000166:cytology; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D006801:Humans; D044085:Microfluidics; D010012:Osteogenesis; D023822:Tissue Engineering
D001672:Biocompatible Materials