Exam 1 prep 1

Question 1

4 steps of wound healing process

Answer 1

1. Injury
2. Coagulation (scab)
3. Inflammation
4. Repair and recovery

Question 2

In vivo meaning

Answer 2

In living organism

Question 3

Aseptic meaning

Answer 3

Sterile; free from contamination

Question 4

Biocompatibility meaning

Answer 4

Capacity of material to not induce toxic or injurious effects on biological systems

Question 5

Classes of biomaterials

Answer 5

Metals, Ceramics, Polymers

Question 5

Metal structure

Answer 5

Sea of electrons

Question 6

Where are metallic biomaterials mainly used for

Answer 6

Load bearing applications
- knee/ hip implants, dental implant, fracture fixation

Question 7

Which (metal/alloy) have greater corrosion resistance or strength?

Answer 7

Alloys

Question 8

Most naturally occurring crystals are (single/poly) crystalline

Answer 8

Poly (sections of perfectly crystalline small parts or grains)

Question 9

Where does dislocation happen in pure metals?

Answer 9

Grain boundaries

Question 10

How is dislocation prevented in alloys?

Answer 10

Packing of two different size of metal elements prevent physical dislcoation

Question 11

Main ceramic for hip implant

Answer 11

Cobalt chromium (Co/Cm) alloy

Question 12

Main metal for hip implant

Answer 12

Titanium alloy

Question 13

Draw stress vs yield graph for metals

Answer 13

Question 14

What does Wolff’s law state

Answer 14

Bones will adapt to degree of mechanical loading

Question 15

Problems arising due to use of metal implants

Answer 15

1. Stress shielding - according to Wolff’s law, bone density will reduce.
2. Biofilm formation
3. Corrosion

Question 16

Biofilm formation steps

Answer 16

1. Initial interactions
2. Expansion
3. Maturation
4. Resistance

Question 17

How to solve biofilm formation

Answer 17

1. Host cell/proteins may attach to metal/polymer surface -> floating bacteria cannot attach directly to surface of implant
2. Anti-adhesive coating
3. Release bactericidal agents from surface (Zn, Hg)
4. Nanotopography to disrupt adhesion

Question 18

How can metal debris/ion possibly be a threat

Answer 18

Low toxicity if combined with biomolecules, high toxicity if it cannot bind to biomolecules

Question 19

Solutions for corrosion of metal implant

Answer 19

Surface modification (passivation)
- Cr2O3 protective oxide layer

Question 20

Draw the stress vs train graph for ceramics

Answer 20

Question 21

Application of ceramics

Answer 21

Orthopedic and dental applications

Question 22

Natural ceramics are tissue-mineral component composites. Give examples of the ceramic and polymer components

Answer 22

Ceramic: hydroxyapatite (gives bones their hardness)

Polymer: tissue, organic polymer fiber

Question 23

Application of HA-like materials

Answer 23

• Non load-bearing applications
• Bone fillers
• Coatings on implants

Question 24

Polymer properties

Answer 24

* Low chemical reactivity * Low density, sensitivity to heat * Poor electricity conductor

Question 25

Most abundant bio macromolecule (proteins, nucleic acids, carbohydrates)

Answer 25

Proteins: collagen Nucleic acids: RNA Carbohydrates: Glycogen

Question 26

Non-degradable, resorbable sutures

Answer 26

Non degradable: UHMWPE Typically outside the body to prevent bacterial infection Resorbable structures: contain ester groups Inside the body

Question 27

Polymer advantage

Answer 27

Infection resistance

Question 28

Describe friction of PE

Answer 28

Low friction

Question 29

2 types of protein structure + respective function

Answer 29

1. Globular: biological catalysts 2. Fibrillar: structure

Question 30

What protein enables cell attachment?

Answer 30

Fibronectin

Question 31

Adsorption is primarily driven by...

Answer 31

Charge interactions/hydrophilicity

Question 32

Where are antibodies

Answer 32

Serum

Question 33

Increased surface topography (increases/decreases) protein adsorption

Answer 33

Increases