midterm 1

Question 1

What are the 3 classes of materials? (and describe them)

Answer 1

1. Metals - metallic bonds, sea of electrons
2. Ceramics - ionic bonds, nondirectional
3. Polymer - covalent bonds, directional

Question 2

What is an example of a metal?

Answer 2

Titanium, gold, etc.

Question 3

What is an example of a ceramic?

Answer 3

NaCl2, Hydroxyapatite

Question 4

What is an example of a polymer?

Answer 4

PEG

Question 5

What is an example use of metal biomaterials?

Answer 5

Dental Implants

Question 6

What is an example use of ceramic biomaterials?

Answer 6

Bone scaffold, hip implants

Question 7

What is an example use of polymer biomaterials?

Answer 7

Drug delivery, skin grafts

Question 8

What are the types of material degradation, and explain what their difference is?

Answer 8

• Surface - layer by layer removing
• Bulk - equal degradation throughout the material

Question 9

What are some traits that can be controlled by changing a material’s surface properties?

Answer 9

• cell adhesion/spread, by modifying the surface texture
• protein interactions

Question 10

What can you do to modify the surface texture?

Answer 10

• • or - charge
• increase the surface energy
• change hydrophobicity

Question 11

What are two mechanical properties? Also, are they surface or bulk?

Answer 11

1. softness/hardness - surface
2. compliance - bulk

Question 12

What is the equation for stress? (and units)

Answer 12

σ=F/A (units N/L^2)

Question 13

What is the equation for strain? (and units)

Answer 13

ε=ΔL / l₀ (units L/L)

Question 14

What are chemical characteristics?

Answer 14

• composition of biomaterial
• chemical structure
• conformation of reaction

Question 15

What are some imaging techniques that can determine chemical characteristics?

Answer 15

• NMR (nuclear magnetic resonance)
• raman spectroscopy
• FTIR

Question 16

What components make up a polymer?

Answer 16

monomers

Question 17

Describe the structure of a copolymer

Answer 17

different repeated monomers

Question 18

What are the steps of addition polymerization? (and products)

Answer 18

1. Initiation - radical combine with double bond to make two single bonds
2. propagation - multiple units chain together
3. termination - stop adding more units

Question 19

What is condensation polymeration? (and products)

Answer 19

Combining multiple chemicals to form a product polymer and water

Question 20

Draw the structure of polyester

Answer 20

-R-O-R-CO- (see pdf)

Question 21

Draw the structure of polyether

Answer 21

-O-R- (see pdf)

Question 22

Draw the structure of polyanhydride

Answer 22

-CO-R-CO-O- (see pdf)

Question 23

Draw the structure of polyamide

Answer 23

-CO-R-NH- (see pdf)

Question 24

Draw the structure of polyurethane

Answer 24

-O-CO-NH-R- (see pdf)

Question 25

What is the equation for PDI?

Answer 25

PDI = Mw / Mn

Question 26

What is the equation for Mn?

Answer 26

Mn = Σ Xi Mi

Question 27

What is the equation for Mw?

Answer 27

Mw = Σ Wi Mi

Question 28

Rank the 4 types of polymer structures from strongest > weakest

Answer 28

Network > Crosslinked > Linear > Branched | strongest > weakest

Question 29

Draw chain-fold structure

Answer 29

/\/\/\/\/\/\/\/\/\/ | wewewewewewewew

Question 30

What is the thermoset process?

Answer 30

to set a polymer using heat

Question 31

What is a thermoplastic?

Answer 31

A plastic that can be reheated to change shape

Question 32

What are examples of elastomers?

Answer 32

* Elastic * Rubbers

Question 33

What are 4 structures of copolymers?

Answer 33

1. Random 2. alternating 3. bulk 4. graft

Question 34

What are types of natural polymers?

Answer 34

1. Polypeptides - protein - amino acids is hetero bifunctional condensation (zein, gelatin, elastin) 2. polysaccharides - sugar (hyaluronic acid)

Question 35

What is a common example of a natural polymer?

Answer 35

DNA (long length, bound with hydrogen bonds)

Question 36

What are the structures of proteins

Answer 36

* 1 (primary): Alu-gly-arg- * 2 (secondary): organization of local amino acids into alpha-helices, beta-sheets, and loops * 3 (tertiary): combine secondary structures * 4 (quaternary): 1+protein

Question 37

What are common side chains for alpha helices? (and examples)

Answer 37

* bulk side chains - uncommon * lack side chain - uncommon (glycine, protein)

Question 38

What are common chemical pairs in beta sheets?

Answer 38

* C-N in parallel * C-N * C-N antiparallel (more stable) * N-C (small hydrogen bond angle)

Question 39

What are advantages and disadvantages of natural polymers

Answer 39

* Advantages: bioinert, bioactivity, hydrated * Disadvantages: highly variable, hard to purify, immune response

Question 40

What are advantages and disadvantages of synthetic polymers?

Answer 40

* Advantages: cheap, reproductive, not animal derived (low immunigenicity) * Disadvantaes: unknown toxicity, no inherent cell interaction

Question 41

What is the equation for degredation? (and what numbers indicate surface vs. bulk?)

Answer 41

rate of hydrolysis / rate of H20 entry | >>1 surface, <<1 bulk

Question 42

What are 3 methods of degredation for polymers? (describe)

Answer 42

1. Biodegredation - mediated by biological agent 2. Bioerosion - physical dissolution 3. Bioresorption - polymers removed by cellular activity

Question 43

What is PEGylation

Answer 43

A process of conjugating one or more PEG polymer to a molecule to modify its size, hydrophobicity, and stability.

Question 44

What are benefits of PEG?

Answer 44

* Making a larger - reduce renal clearance * Stability - harder to degrade * Hydrophobicity - last longer * Increase circulation half-life

Question 45

What is bioconjugation? (give details)

Answer 45

A + B --> A-B (conjugation) The inative group A reacts with the initiating group EDC to form an active intermediate. This reacts with coupling target B to form the stable conjugate product A-B.

Question 46

What is the most useful functional group in cysteine?

Answer 46

SH

Question 47

What is the most useful functional group in serine and threonine

Answer 47

OH

Question 48

What is the most useful functional group in tyrosine?

Answer 48

PhOH

Question 49

What is the most useful functional group in lysine?

Answer 49

NH2

Question 50

What is the most useful functional group in aspartic and glutamic?

Answer 50

CO2H