Lecture 25 - Polymers for Tissue Regeneration/In Vitro Disease Models

Question 1

Engineered Tissues

Answer 1

Applications:

• Replace diseased/damaged tissue or aren’t there because of congenital defect
• Enhance function/regeneration of injured tissues
• Organotypic models (pharmaceutical design/testing - personalize testing, cosmetic testing - no animal models, disease progression - molecular mechanisms and therapies)

Question 2

Mimicking Natural Organs

Answer 2

• Cell constituents (organization of cells)
• Tissue architecture
• ECM (composition, mechanical properties)
• Normal/regeneration

Question 3

Importance of Scaffold Chemistry

Answer 3

• Scaffold chemistry (cell adhesion)
• Not all polymers compatible with all cells
• Polymer must facilitate seeding/cell infiltration process (related to hydrophilicity/hydrophobicity)

Question 4

How to Choose Scaffold Chemistry

Answer 4

• Select biopolymer native to tissue
• Examine prior art (work)
• Functionalize surface with cell specific adhesion molecules
• Test wide variety of synthetic polymers

Question 5

Role of Wettability: Combinatorial Libraries

Answer 5

• Toxicity
• Adhesion, spreading, proliferation
• Gene expression/protein production

Question 6

Role of Wettability: Incorporation of Cell into Polymer Implant

Answer 6

• Polymer might be hydrophobic
• Enhance wettability of scaffolds by pre-wetting the scaffold by soaking in protein solution and surface modifications (plasma treatment, surface or grafting of peptide or polymer)

Question 7

Cell Incorporation into Scaffolds

Answer 7

Static:
- Pipeting
- Cell printing
Dynmaic:
- Vacuum seeding and flow seeding methods
- In process incorporation —> during polymerization/fibrilligensis process (hydrogels), during polymer processing (electrospinning, 3D printing)

Question 8

Cell Manufacturing

Answer 8

• Additive cell incorporation (blood vessels, skin)

- Cell incorporation during fabrication (3D print, hydrogel, electrospin)

Question 9

Scaffold Directive

Answer 9

• Patterned adhesion for specific cells

- Guided inoculation (push cells)

Question 10

Patterned Adhesion for Specific Cells

Answer 10

• Plasma treat through mask (only reacts with areas not covered)
• Surface grafting
• Topography (align cells)
• Injection channels