Degradation And Bioresorption

Question 1

What are the key advantages of Bioresorbable polymers?

Answer 1

Enables transfer of loads to healing bone

Avoids complications involved with metal implants

Question 2

Hydrolysis results in

Answer 2

Chain scission

Question 3

What is the ester hydrolysis reaction?

Answer 3

RCOOR’ + H2O <=> RCOOH + R’OH

Ester + water Acid + Alcohol

Question 4

Why is glass transition temp important?

Answer 4

Going above glass transition temp results in less stiff, more ductile and less brittle properties

Question 5

What is happening here?

Answer 5

Surface Erosion
(H2O breaks down polymer faster than it is absorbed)

Question 6

What is happening here?

Answer 6

Bulk Erosion

H20 is absorbed by polymer faster than it is degraded

Question 7

How could this be described?

Answer 7

Heterogeneous Bulk Erosion

Question 8

What are the 5 factors effecting degradation in Bioresorbable polymers?

Answer 8

• More Crystallinity = Less deg
• More Molecular Weight = Less deg
• More Temperature = More deg
• More or Less pH = More deg
• Additives can control deg

Question 9

How are bioresorbable polymers tested for degradation times?

Answer 9

Elevated Temperatures because of Arrhenius Relationship