Exam 2 cartilage TE

Question 1

What is cartilage?

Answer 1

Connective tissue made up of chondrocytes embedded in a matrix (collagen/sugars)

Question 2

What are cartilage cells?

Answer 2

Chondrocytes

Question 3

What is cartilage made of?

Answer 3

65-85% water
10-30% collagen
3-10% proteoglycans

Question 4

What are the types of cartilage?

Answer 4

Elastic, hyaline, and fibrous

Question 5

What is hyaline cartilage?

Answer 5

Most commonly found in joints, provides a smooth articulating surface, mostly type II collagen

Question 6

What is elastic cartilage?

Answer 6

Flexible cartilage found in ears that are made of elastin

Question 7

How does the swelling pressure of cartilage work?

Answer 7

Due to negatively charged proteoglycans attracting water and ions
Provides resistance to compression

Question 8

Explain how cartilage’s elastic behavior benefits it.

Answer 8

Solid matrix provides structural integrity and load support

Question 9

How do the properties of cartilage change with age?

Answer 9

• Proteins: Collagen cross-linking increases (stiffer, less elastic)
• Glycans: Decrease in glycosaminoglycans (GAGs), reduces water retention
• Water content: Decreases with age
• Mechanical properties: Tissue becomes stiffer, less resilient

Question 10

True/False: Chondrocyte orientation and matrix organization changes with depth

Answer 10

True

Question 11

Why doesn’t cartilage heal?

Answer 11

• Limited progenitor cells: Few stem cells present in cartilage
• No vascular supply: No blood flow, so nutrients and cells can’t easily reach damaged areas

Question 12

What are the current treatments for damaged or missing cartilage?

Answer 12

microfractures and grafting procedures

Question 13

How does the TE approach apply to cartilage (cells)?

Answer 13

-Chondrocytes as the cartilage cells
-Stem cells (MSCs, ESCs, iPSCs) can differentiate into chondrocytes when stimulated by signals like TGF-β3, providing an expandable and versatile cell source for cartilage repair.

Question 14

How does the TE approach apply to cartilage (scaffolds)?

Answer 14

• Hydrogels retain water to mimic the high water content of natural cartilage and support nutrient diffusion.
• Sponges and fibrous meshes provide porous structures that support cell attachment, proliferation, and matrix deposition.

Question 15

What defines cartilage mechanics?

Answer 15

1. Swelling pressure due to ionic
   properties
2. Elastic behavior of the solid matrix
3. Fluid-solid interactions