Degradable and Resorbable Polymers

Question 1

Advantages

Answer 1

NO surgical removal
NO long-term stability issues (rejection, failure)
Drug delivery devices

Question 2

Disadvantages

Answer 2

Toxicity of products
Premature filure
Leachables
Long enough mechanical integrity

Question 3

Apps.

Answer 3

Drug delivery devices
Sutures
Patches

Question 4

Degradation

Answer 4

chemical process by cleavage of chemical bonds
Can break into monomers
MW -, mass remains

Question 5

Biodegradation

Answer 5

Degradation by enzyme, cell or microorganism

Question 6

Bioerosion

Answer 6

Conversion of water-insouble to water-soluble

Question 7

Erosion

Answer 7

Physical change in size, shape, or mass

mass loss

Question 8

Examples

Answer 8

PGA

PLA

Question 9

PGA

Answer 9

Highly crystalline
High Tm and low solubility
Sutures and bone pins

Question 10

PLA

Answer 10

Crystalline and amorphous
Amor. used for drug delivery
Semi-cry. used where high mech strength and toughness are required (sutures orthopedics)

Question 11

PGA/PLA issues

Answer 11

Cells do not attach or grow as vigorously
- human
+ bacteria

Question 12

PDS

Answer 12

Byproducts have - toxicity

Appx. 60 days

Question 13

PCL

Answer 13

Degrades slower than PLA

Can deliver drugs over a year

Question 14

Polyanhydrides

Answer 14

Single step synthesis
Controllable MW
Predictable degradation / drug release
From days to years