Results : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
Our analysis was focused on two main aspects:
Simulation of the fluid flow characteristics as well as quantification of the arising shear forces at the plate/plate flow chamber with reliable reproducibility
Assessment of the impact of fluid shear stress on osteoblast cells in terms of altered cell morphology and intracellular structural changes
The computational fluid dynamic analysis and the quantification of the occurring shear forces within the plate/plate flow chamber were central part of this investigation. The cellular-fluid flow setup was based on the fact that osteoblast cells show responses at 10 dyn/cm2 at a speed level of 200 rpm.
On the topside of the upper plate (rotating glass panel), the computerised simulations demonstrated a gradient increased flow with shear forces from the centre (1 dyn/cm2) to the periphery (10 dyn/cm2). Minor effects of shear forces (0–2 dyn/cm2) were recorded on the surface of the bottom plate. It could be demonstrated that a bigger radius of rotation correlates with higher shear forces as expressed in formula 1. Further simulations aimed to verify the pattern of fluid flow (laminar versus turbulent flow). For this purpose, the conditions on the upper and lower surface of the upper plate as well as in the area in between the two plates were of particular interest. The simulations revealed a strong turbulent flow on the entire top surface of the upper plate, especially in the centre and the area around the circumferential edges (Fig. 2). The flow from the peripheral region turned backward and amplified the turbulent flow on the top surface. The development of two opposite flow directions was observed within the area in between the plates. The flow along the lower plates’ surface was directed from the periphery to the centre whereas the fluid movement along the underside of the upper plate was inversely orientated (Fig. 2). Regarding the upper compartment, peripheral turbulent flow along the outer edges was similar to the fluid movements within the area in between the plates. At the top, the turbulent flow directed from the centre to the periphery whereas the turbulences at the bottom were orientated in reverse to that. Moreover, the effect of the shear forces on the osteoblast cells was also influenced by the centrifugal force. This force can be calculated using formula 3:
Serial posts:
- Abstract : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- Background : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
- Background : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [2]
- Methods : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
- Methods : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [2]
- Results : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
- Results : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [2]
- Discussion : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
- Discussion : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [2]
- Discussion : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [3]
- Conclusions : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- Abbreviations : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- References : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
- References : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [2]
- References : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [3]
- References : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [4]
- Acknowledgements : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- Author information : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [1]
- Author information : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up [2]
- Rights and permissions : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- About this article : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- Table 1 Listing of the single components of the flow chamber together with manufacturers’ data : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- Table 2 Listing of the culture media and additives together with manufacturers’ data : Cellular fluid shear stress on implant surfaces—establishment of a novel experimental set up
- Fig. 1. Three-dimensional illustration (a–e) and photography (f) of the experimental setup with the components marked numerical. a1 Lower petri dish (s’ bottom serving as the lower plate); 2 Rotating glass panel [60 mm diameter (cell bearing)]; 3 Titanium axis. b4 Liquid medium (red). c5 Reversed upper petri dish. d6 Gearwheel with set screw. e7 Closing; 8 Electronic motor device and adjusting ring with additional set screw : Cellular fluid shear stress on implant
- Fig. 2. Side view of a computerized simulation, showing the flow chambers’ lower compartment and the flow profile in between the two plates; shearing gap and bottom plate are shown on the left side; rotation speed = 200 rpm; colour code bar (left edge) showing shear force values [Pa] [1 Pa = 10 dyn/cm2]; flow direction presented by arrows : Cellular fluid shear stress on implant
- Fig. 3. Diagram for visualisation of the calculation of shear stress rates taking into account the centrifugal force and the glass plates’ dimensions. For example, at a distance of 25 mm from the centre of the upper plate, the shear forces’ value is 8.33 dyn/cm2, together with an additional centrifugal force that has a value of 0.55 dyn/cm2 : Cellular fluid shear stress on implant
- Fig. 4. Randomly orientated osteoblasts without influence of rotation (phallacidin fluorescence staining). On the left side with 200× and on the right side with 400× magnification. The white X on the coloured circle marks the location upon the plate where the osteoblasts were located. The red X marks the centre of the plate : Cellular fluid shear stress on implant
- Fig. 5. Osteoblasts with an orientation tendency after 24 h of rotation (phallacidin fluorescence staining). On the left side with 200× and on the right side with 400× magnification. The yellow arrows show the orientation of the cells. The red arched arrow within the coloured circle shows the direction of rotation. The dashed white line oriented to the right stands for the resulting centrifugal force. The dashed white line pointing upwards shows the direction of the resulting flow resistance. The solid white arrow stands for the vectorial sum of the abovementioned forces : Cellular fluid shear stress on implant