Discussion : Cellular fluid shear stress on implant surfaces (3)
Due to the fact that constant flows were generated within the parallel flow chamber only, the situations of in vitro experiments differ from in vivo setting where dynamic flow profiles are particular. As the constant laminar flow profile is not physiological in bones, vessels and other tissues, the informative value of the experimental setting is limited but it could be used for various cell proliferation and differentiation modulations. In accordance with this, constant laminar flows were rated to have more impact on target cells than pulsatile and oscillating flow profiles. With regard to these findings, the flow profile generated within the reported device meets the requirements to induce cell morphology changes by FSS.
In addition, when using the new flow chamber, an additive effect of FSS and centrifugal forces on the cells could be seen. Other flow chambers did not reveal this phenomenon due to the fact that the liquid flow moves along a stationary cell surface only.
When comparing this new fluid flow chambers with other reported devices, several differences are seen. Commonly, test cells are placed on a fixed surface with the culture medium flowing along. According to the method of flow generation, they can be classified into open and sealed systems. Open systems, which are hydrostatically driven, are characterised by a fluid flow that passes the stationary phase once only. In sealed models, the culture medium recirculates pump driven through the system. Due to their inherent system-related drawbacks such as turbulent flow generation on boundary surfaces, those flow chambers are inappropriate for laminar flow creation. However, open systems have benefits of allowing the use of different culture media in a row without ceasing the fluid shear stress. Therefore, one can easily enable or disable different stimuli by exchanging the culture medium to evaluate its cellular impact. Sealed systems such as reported in this study do not provide this option. Initially added substances within the culture medium cannot be eliminated during the experimental process. Instead, stopping the flow and draining the cells would be necessary which would cause another unwanted influence to the test cells.
Serial posts:
- Cellular fluid shear stress on implant surfaces
- Methods : Cellular fluid shear stress on implant surfaces (1)
- Methods : Cellular fluid shear stress on implant surfaces (2)
- Methods : Cellular fluid shear stress on implant surfaces (3)
- Results : Cellular fluid shear stress on implant surfaces (1)
- Results : Cellular fluid shear stress on implant surfaces (2)
- Discussion : Cellular fluid shear stress on implant surfaces (1)
- Discussion : Cellular fluid shear stress on implant surfaces (2)
- Discussion : Cellular fluid shear stress on implant surfaces (3)
- Discussion : Cellular fluid shear stress on implant surfaces (4)
- References : Cellular fluid shear stress on implant surfaces
- Figure 1. Three-dimensional illustration and photography
- Figure 2. Side view of a computerized simulation
- Figure 3. Diagram for visualisation of the calculation of shear stress rates
- Figure 4. Randomly orientated osteoblasts without influence of rotation
- Figure 5. Osteoblasts with an orientation tendency after 24 h