Module 8 and 10

Question 1

Solid-state interaction confer effects

Answer 1

Physical distortion: results from force transmissions between cell and materials due to spatial proximity

Chemical signaling: results in activation/repression of signaling cascades through interactions with insoluble structures

Adhesion points: at subcellular sites at the cell-material interface are physiochemical connections between specialized subcellular sites at the cell membrane and specific components of the material surface

Question 2

Major cell-matrix adhesion receptors

Answer 2

Integrins: are transmembrane heterodimeric proteins that act as mechanotransducers - translate extracellular mechanical stimulations into intracellular responses

Question 3

Mechanotransduction leads to…

Answer 3

changes in gene expression
(Look at Module 8 Figure 19)

Question 4

Surface chemistry

Answer 4

the chemical properties of the surface of the material in addition to any other modifications that are added to the surface
1.) hydrophobicity v.s. hydrophilicity
2.) Presentation of chemical groups
3.) Patterning of chemical groups

Question 5

Cells prefer to migrate from…

Answer 5

softer to stiffer regions

Question 6

Substrate stiffness can influence…

Answer 6

stem cell differentiation along a particular lineage

Question 7

What is surface topography?

Answer 7

physical patterning (architecture) of the material surface

Question 8

Key parameters for developing a polymer microarray

Answer 8

1.) Base substrate
2.) Substrate coating
3.) polymer library
4.) Biological assay

Question 9

Requirements for TE scaffolds

Answer 9

1.) Provide sufficient initial mechanical strength.
2.) Maintains sufficient structural integrity
3.) Possess surface properties
4.) Manufactured under cGMP conditions.
5.) Manufactured economic cost and speed

Question 10

Porosity

Answer 10

A collection of pores, high porosity may provide a greater pore volume for infiltration and ECM formation, but conversely decreases mechanical properties.

Question 11

Interconnectivity and Accessibility

Answer 11

The size of interconnections between pores should be suitably large to support cell migration and proliferation in the initial stages and consequent ECM infiltration of desired tissue and, therefore, is more critical than pore size.
(Look at Module 10 Figure 2)

Question 12

Two-photon Polymerization

Answer 12

The method is a subset of SLA. The resolutions are exceptional with nanoscale tolerances and the ability to produce very small pores and highly detailed structures.
Reactive species generated during 2PP, cause of cellular toxicity

Question 13

Hybrid Fabrication

Answer 13

A common trend is to combine manufacturing approaches so that the benefits of each are provided while minimizing their disadvantages.
Example: electrospinning can be combined with melt electrowriting (MEW) to provide the volume and mechanical properties.
(Look at Module 10 Figure 7)