The three questions are about tissue engineering, please answer the questions precise and no more 100 words for each answer

Answer the following questions (no more than 100 words for each answer)

1. Look at the data in following figure, which shows the GAG distribution for cylindrical chondrocyte-seeded PGA scaffold constructs under free-swelling (control) and perfusion with static or dynamic loading in axial, unconfined compression

1. Is the effect of perfusion or dynamic applied loading (in general) greater on GAG distribution? Explain by using the data in figure

2. The faces of the construct with perfusion + loading lose less GAG to the media than free-swelling control. How might this be related to the boundary conditions of applied loading?

Figure: GAG concentration profiles at construct surfaces. GAG concentration measured by image processing of histological section is shown as a function of distance from the construct surface (representative static load group shown). Note the definition of the construct regions for analyses. Loading is applied to the construct in the axial direction (arrow)

1. A schematic diagram of modified cone-plate viscometer is shown in following figure, and is designed specifically for use with a specialized culture plate with a porous filter insert, whereby endothelial cells are grown on the filter insert resting at its center on a microscope slide cover affixed to the bottom plate (to provide support). Smooth muscle can be grown on the bottom surface (where there is media that is contiguous with above)

1. If the motor that applied angular rotation (w) to the cone is already at its maximum setting, how could one further increase the applied shear level? Explain

2. If one were interested in looking at a traumatic injury response to the endothelial cells, how would one achieve this in the system?

3. In the figure, why is the porous filter incorporated into the design? (i.e., what are they hoping to study?)

4. What are the shear conditions in the device with respect to radial distance from the center of the plate?

figure: modified cone-plate viscometer

1. A hydrostatic pressure bioreactor is used to stimulate growth of high density (very confluent) culture of chondrocytes (From Smith and co-workers, IOR, 1996). A radioactive assay is employed to measure the GAG content of the culture, see the table

1. If cells were seeded in a 3D scaffold system, how might you expect these results to change in terms of this distribution of GAG and why?

2. Cells cultured in 3D scaffolds can be loaded under physiological levels of hydrostatic pressure irrespective of their mechanical properties, why?

3. For deformational loading bioreactors, convective transport is thought to contribute to the stimulatory effects on engineered cartilage tissue growth. Would convection play a similar role for hydrostatic pressure? Explain briefly