Class Notes Flashcards

(97 cards)

1
Q

Biomaterial

A

A material intended to interface with biological systems to evaluate, treat, augment, or replace any tissue, organ, or function of the body

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2
Q

What are some important considerations for biomaterials?

A

Biocompatible, permeability, durability, microbial resistance, sterile, promote normal healing, appropriate material properties

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3
Q

How old is the biomaterials field?

A

60-70 years old

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4
Q

What are the nonpolar/hydrophobic/non-polar/aliphatic amino acids?

A

GAVLIP:

Glycine, Alanine, Valine, Leucine, Isoleucine and Proline

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5
Q

What amino acids have aromatic side chains(hydrophobic)?

A

PTT:

Phenylalanine, Tyrosine, Tryptophan *Tyrosine is the only polar aromatic side chain group

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6
Q

What amino acids have negative charge(are acidic)?

A

Glutamate, aspartate(AG-ing is often seen as negative)

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7
Q

What amino acids have a positive charge(basic)?

A

HAL

Histidine, Arginine, Lysine, (Hal is always positive- Malcolm in the middle)

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8
Q

List the alcoholic amino acids.

A

Threonine, Serine

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9
Q

List the amide amino acids.

A

Glutamine, Asparagine

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10
Q

List the sulphur-containing amino acids.

A

Cysteine, Methionine

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11
Q

What are the polar/uncharged/hydrophillic amino acids

A

G(ood) CATS

Glutamine, Cysteine, Asparagine, Threonine, Serine

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12
Q

Biocompatibility

A

The ability of a material to perform with an appropriate host response in a specific application

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13
Q

Surface material properties

A

Physical and chemical characteristics of the surface of a material that dictate interactions between the environment and the material

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14
Q

Bulk material properties

A

Include intrinsic, extrinsic, microstructure, and optical properties that occur when you have a lot of material.

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15
Q

Surface vs interface

A

A surface is the boundary region between two adjacent bulk phases. If there is a direct connection with no gaps or a material is piled on top of itself, then there is no surface, but only an interface. There is always an interface between two bulk phases- even if the phases are the same. *Remember that surfaces are not two dimensional (figures will represent the nearest geometric approximation usually)

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16
Q

What are some examples of surface properties?

A

Topography/Roughness, Chemical Composition/reactivity, surface energy/tension, discreet structure/surface layers, surface viscosity, color

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17
Q

What are intrinsic properties?

A

Properties that depend primarily on the composition of the matter including density, heat capacity, and odor.

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18
Q

What are extrinsic properties?

A

Properties that depend on the amount of matter present such as volume, mass, weight, size, length, and area.

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19
Q

Microstructure properties:

A

depend on the types of atoms and their arrangments *different scales (10^-3 to 10^-9), so we always need to include a scale bar

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20
Q

Thermal conductivity equation:

A

ΔQ/ΔtA = -k ΔT/Δx ; where the term on the left is the power per unit area transported and T is the temperature gradient and k is the thermal conductivity constant.

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21
Q

Linear thermal expansion equation:

A

ΔL = αLΔT, where ΔL = change in length, ΔT = change in temp, and α is the linear expansion coefficient, which varies slightly with temperature.

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22
Q

What is transparency?

A

The ability of a material to transmit light without absorbing or scattering it

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23
Q

What is refractive index?

A

Refractive index is how much the angle of light deviates from its original angle as it crosses a material

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24
Q

What are some examples of optical properties? (bulk properties)

A

Color, refractive index, transparency

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25
What is a surface?
The boundary region between two adjacent bulk phases.
26
True or false. Every surface has an interface, but not every interface has a surface.
True
27
What are some examples of alloys?
Stainless steel, titanium-based alloys and cobalt alloys
28
What are some things implants are used for?
Osteosynthesis, joint replacements and spine implants
29
What is osteosynthesis?
Internal fixation of a bone fracture
30
What do joint replacements do?
Increase joint function either partially or fully
31
What are the differences between spine implants and joint replacements?
the orientation and the tissue structure
32
What is an alloy?
A metallic compound made up of one or more metal or non-metal elements
33
What are the advantages to making an alloy?
You can make your material stronger, have different stress-strain properties, and interact differently with biological systems
34
What is the base in an alloy?
The primary metal in the alloy (also called the matrix or the solvent)
35
True or false. For a substitutional alloy, the alloy atoms are similar in size to the base atoms.
True
36
What does interstitial indicate?
That atoms cannot fit in to the matrix, so they occupy the spaces in between
37
What are some examples of physical properties of metals?
Luster, good conductors of heat and electricity, high density and melting point, ductile, malleable
38
What metals and/or non metals make up stainless steel?
Iron(62%), chromium(18%), nickel(16%), molybdenum(3%), and carbon(< 1%).
39
What are the advantages of stainless steel?
Stainless steel is strong, ductile, bio-compatible and relatively cheap
40
What are some disadvantages of stainless steel?
Stainless steel is susceptible to crevice and stress erosion.
41
What metals make up titanium alloys?
Titanium(89%), aluminum(6%), vanadium(4%), and others(1%)
42
What are the advantages of titanium alloys?
Titanium alloys are corrosion resistant, ductile, MRI scan compatible, and have excellent biocompatibility
43
What are some disadvantages of titanium alloys?
Titanium alloys are relatively expensive, have poor wear characteristics and have notch sensitivity
44
What are the three types of crystal structures?
Crystalline, polycrystalline, and amorphous
45
In crystalline structures, how are atoms arranged?
In a fixed pattern, giving us long range order
46
In crystalline structures, how are atoms arranged?
More chaotically, they lack a defined arrangement, which makes these structures more similar to liquids at the atomic level.
47
True or false. Amorphous crystals act like liquids.
False, although they are similar at the atomic level, they don't necessarily flow like liquids. Glass is an example of this.
48
True or false. Metal ionic bonding in non-directional.
True
49
What is a unit cell?
A basic repeating unit of a crystal in three dimensions.
50
What does each dot on a unit cell represent?
The center of an atom
51
What is the definition of coordination number?
The number of nearest neighbor atoms
52
What is APF?
Atomic packing factor, equal to the volume of atoms in a unit cell divided by the total unit cell volume
53
What type of model does APF assume?
Hard-sphere model of atoms
54
Where are atoms located in Face Centered Cubic (FCC)?
In the corners of each unit cell and the centers of each face
55
How can unit edge length and atomic radius be related in FCC?
a = 2r (sqrt2)
56
How many equivalent atoms are there in FCC?
4
57
What are some examples of FCC?
aluminum, copper, lead, silver, and gold
58
What is the coordination number of FCC?
12
59
What is the APF for FCC?
0.74
60
What is the volume of atoms in FCC?
16/3*(pi)*r^3
61
What is the volume of the unit cell in FCC?
16*(r^3)*(sqrt2)
62
What is the coordination number for BCC?
8
63
How many equivalent atoms in BCC?
2
64
How can the unit edge length and atomic radius be related?
a = 4r/(sqrt3)
65
What is the APF of BCC?
0.68
66
What is the APF of HCP?
0.74
67
How is HCP organized?
Into alternating stacks (abab), the structure repeats every two layers
68
What are ceramic materials?
solid materials composed of inorganic, non metallic substances such as porcelain, cement and glass
69
What are ceramic materials used for in clinical applications?
Repair of the skeletal system including: skeletal implants, coatings, bone cements, grafts, and dental applications
70
What are some types of bio-ceramics?
Alumina, Zirconia, Bioglass, Hydroxyapatite, and tricalcium phosphate
71
What are some examples of natural ceramics?
Clay and bone (mineral- like HA)
72
What is ossification?
Formation of bone
73
What are osteoblasts?
Cells that secrete bone matrix
74
What are osteoclasts?
Cells that degrade bone
75
What are osteocytes?
Cells that maintain bone
76
What are osteogeneic cells?
Osteoprogenitors; stem cells of bone that form osteoblasts
77
What are the parts of long bone?
Spongy bone, an epiphyseal line, compact bone, and yellow bone marrow
78
What are the parts of the tooth?
Enamel, dentin and pulp (considered part of the dentin)
79
What does enamel consist of?
A hard outer surface with 96% hydroxyapatite (it's stronger than bone)
80
What does dentin consist of?
45% HA, 33% organic material, 22% water (yellow in color)
81
What does pulp consist of?
Living connective tissue (considered part of dentin)
82
What are some characteristics of ceramics?
Ceramics are brittle, have high hardness, high thermal resistance, high electrical insulation and good corrosion resistance
83
If the Rc/Ra ration is larger than or equal to our ideal relative sizes, then what can we say about our structure?
That it is stable
84
If the Rc/Ra ratio is less than our ideal ration, what does that say about our ceramic crystal structure?
That it is unstable
85
True or false. A single coordination number can produce stable or unstable structures depending on the relative sizes of the ions.
True
86
What happens when you replace the F- with OH in HA?
Increase of crystallinity, crystal size and stability of apatite, also reduces solubility (used in toothpaste, won't wear down our teeth)
87
What happens in a calcium phosphate ceramic if a carbonate substitution is made?
The ceramic becomes more soluble
88
Characteristics of Polyethylene (PE)
Most common artificial polymer used in grocery bags, shampoo bottles and toys. Usually produced as a straight linear chain or branched.
89
Characteristics of Polytetrafluoroethylene (PTFE)
Very hydrophobic fluoropolymer such as teflon that was discovered when a tetrafluoroethylene bottle was catalyzed by iron residues
90
Characteristics of Polypropylene (PP)
Second most commercial polymer that is nonpolar and slightly harder and more heat resistant than polyethylene
91
Characteristics of Polyvinyl chloride (PVC)
Linear and strong with very high hardness that is used for pipes, electric cables and flooring. ATACTIC, and the most heavily modified polymer by use of plasticizers, stabilizers, impact modifiers, biocides and pigments
92
Polydimethylsiloxane (PDMS)
An organosilicone that is optically clear, viscoelastic, inert, non-toxic and non- flammable. It is used in contact lenses, caulking and as an anti-foaming agent
93
Poly (methyl methacrylate) (PMMA)
Acrylic or acrylic glass that is shatter resistant (bulletproof)
94
Poly (hydroxyethyl methacrylate) (PHEMA)
Forms a hydrogel in water and is used in optical implants. Also used to coat cell culture flasks to prevent cell adhesion and induce spheroid formation.
95
Polyethylene Terephthalate (PET)
Used in soft drink plastic bottles | ex: polyester
96
True or false. In traditional polymer synthesis, each polymer chain will have the same degree of polymerization.
False. They will not have the same degree of polymerization!
97
What is the consequence of the fact that polymer chains don't have the same degree of polymerization?
Polymer systems will have a distribution of molecular weights, which affects the physical behaviors of the polymer.