1.Fundamentals Flashcards

1
Q

Biocompatibility

A

“The ability of a biomaterial to perform its desired function with respect to a medical therapy, without eliciting any undesirable local or systemic effects in the recipient or beneficiary of that therapy, but generating the most appropriate beneficial cellular or tissue response to that specific situation, and optimizing the clinically relevant
performance of that therapy.”

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2
Q

Host response

A

prevent bacterial colonization, stimulate the healing, resistance to blood clotting, etc.;

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3
Q

Long-term implantable device

A

“Ability of the device to perform its intended function, with the desired degree of incorporation in the host, without eliciting any undesirable local or systemic effects in that host”.

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4
Q

Scaffolds or matrices for tissue regeneration

A

“Ability to perform as a substrate that will support the appropriate cellular activity, including the facilitation of molecular and mechanical signaling systems, in order to optimize tissue regeneration, without eliciting any undesirable effects in those cells, or inducing any undesirable local or
systemic responses in the eventual host”.

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5
Q

Tissue Engineering

A

“The use of cells, biomaterials and suitable molecular or physical factors, alone or
in combination, to repair or replace tissue to improve clinical outcomes”

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6
Q

Scaffold

A

“A biomaterial structure that serves as a substrate and guide for tissue repair and
regeneration”

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7
Q

1st generation of biomaterial

A

Materials available in nature such as wood, gold and ivory;
Replacement of a lost tissue function.

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8
Q

2nd Generation of biomaterials

A

Developed from materials used in several industrial applications;
Example: stainless steel.

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9
Q

Major issues of 2nd Generation of Biomaterials

A

Weight;
Interaction with biologic tissues

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10
Q

3rd Generation of biomaterials

A

Functional biomaterials;
Bioactive materials - able to develop strong interactions with the surrounding
environment.

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11
Q

4th Generation of biomaterials

A

Multifunctional and biomimetic biomaterials;
Recapitulate complex biological constructs formed by nature.

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12
Q

The Biomaterials’ path

A

1.Reserch on biomaterials
2.Engineering to develop a medical device
3.Preclinical and clinical testing
4.Regulatory approval
5.Commercialization and clinical application

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13
Q

Challenges on the Biomaterial’s path

A

-define requirements of the biomaterial
-select appropriate biomaterial
-understand how long does it take to develop a biomaterial for clinical use

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14
Q

Steps

A

1.indentify a need
2.device design
3.material synthesis
4.material testing
5.fabrication
6.sterilization and packaging
7.device testing
8.regulatory
9.clinical use
10.explant analysis

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15
Q

What kind of questions/issues do you realize when thinking about the sterilization of medical implants?

A
  • How would one sterilize a total hip replacement made of a titanium stem, a cobaltchromium
    alloy head, and an ultra-high molecular weight polyethylene acetabular shell?
  • The same method could be employed for all materials?
  • How do you ensure that there is no degradation to the material or its structural properties?
  • What are the sterilization methods available for medical implants?
  • Which method is best suited for a specific biomaterial?
  • How sterilization methods affect material properties such as structural and degradation?
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16
Q

Mechanism of Autoclaving

A

High-pressure steam (121ºC) disables DNA

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17
Q

Benefits of Autoclaving

A

efficient
easily accessible

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18
Q

Autoclaving Drawbacks

A

High Temperature

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19
Q

Which materials can be sterilized with autoclaving?

A

only metals and ceramics
not polymers

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20
Q

Benefits of sterilization with gamma irradiation

A

efficient
penetrating

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21
Q

Drawbacks of sterilization with gamma irradiation

A

radiation damage

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22
Q

Benefits of sterilization with electron-beam irradiation

A

efficient
surface treatment

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23
Q

Which materials can be sterilized with gamma radiation?

A

metals
ceramics
polymers

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24
Q

Drawbacks of sterilization with electron-beam irradiation

A

Radiation damage
limited penetration

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25
Which materials can be sterilized with electron beam radiation?
metals ceramics polymers
26
Benefits of sterilization with ethylene oxide gas
no radiation damage surface treatment
27
Mechanism of sterilization with ethyleneoxide gas
alkylating agent disables DNA
28
drawbacks of sterilization with ethyleneoxide gas
requires extra time for outgassing requires special packaging
29
Which materials can be sterilized with ethylene oxide gas?
metals ceramics polymers
30
benefits of sterilization with gas plasma
low temperature no radiation damage surface treatment
31
drawbacks of sterilization with gas plasma
limited penetration requires special packaging
32
Which materials can be sterilized with gas plasma?
ceramics metals polymers
33
REPAIR
* Natural process augmented by products regulated as drugs, devices, or biologics.
34
REPLACE
Partly functional replacement of diseased or damaged tissues or organs, often without replication of natural structure (e.g., prostheses, artificial organs, transplants or grafts).
35
REGENERATE
Generation of new tissue with functional and structural properties similar to native tissue or organ.
36
Bioinert
There are no chemical reactions at the implant–living tissue interface; * These materials are usually isolated by a layer of fibrous tissue, although in some cases, they may establish a direct contact with the adjacent tissue.
37
Bioactive
Ability to establish chemical bonds with the surrounding tissues; Example: osseointegration in bone tissue, consisting on the deposition of collagen and mineral phase directly on the implant surface.
38
Biomimetic
Biomaterials capable of mimicking natural materials and/or created by inspiration derived from nature; Strategy explored in several approaches in regenerative medicin
39
Biomaterials can be processed into different physical forms depending on the application
fibers meshes foam particles tubular
40
application in skeletal system
joint replacements trauma fixation devices spine disks and fusion hardware bone defect repair bone cement cartilage, tendon, or ligament repair and replacement dental implant-tooth fixation
41
applications in cardiovascular systems
vascular grafts,patches heart valves pacemakers implantable defibrillators stents catheters
42
applications in opththalmology
contact lens intraocular lens glaucoma drains
43
which materials can be used in joint replacement applications
Titanium CoCr Polyethylene Alumina Zirconia
44
which materials can be used in bone defect repair applications
calcium phosphate hhuman bone products
45
which materials can be used in bone cement applications
PMMA glass polyakkenoate calcium phosphate cements
46
which materials can be used in cartilage, tendon, or ligament repair and replacement applications
decellularized porcine tissue poly(lactide) and metallic fixation devices collagen hyaluronic acid lubricants
47
which materials can be used for pacemakers
titanium polyurethane
48
which materials can be used in stent applications
stainless steel nitinol CoCr Mg alloys PLA poly(lactic-co-glycolic acid)
49
which materials can be used in catheters (cardiovacular,urologic and others)
PTFE poly(ninyl chloride) silicone polyurethane
50
which materials can be used in skin substitutes (chronic wounds, burns)
collagen cadaver skin alginate polyurethane carboxymethylcellulose nylon silicon
51
which materials can be used in ophthalmologic applications such as contact lenses
PMMA PHEMA polyvinyl alcohol PDMS
52
which materials can be used for sutures
silk nylon poly(glycolic acid) PLA polydioxanone polyester copolymers polypropylene PTFE processed bovine tissue
53
Medical device ISO 10993
Any instrument , apparatus , implement , machine , appliance , implant , reagent for in vitro use, software, material or other similar (...) intended to be used, alone or in combination, for human being for one or more of the specific medical purpose
54
Implant ISO 10993
Medical device which is intended to be totally introduced into the human body or to replace an ephitelial surface
55
advantages of *in situ* tissue regeneration
-leverage body's innater regenerative potential -improved shelf life -lower cost -scalable -consistent quality
56
Limitations of *in situ* regeneration
-inneffective for tissue with limited endogenous pregenitor stem cells -difficult to monitor the regeneration process
57
Limitations of traditional tissue engineering
-requires compatible cell source -requires complex culture conditions -poor homing -poor engraftment efficacy -expensive -donor site morbidity -immune reaction
58
Homing
Homing is the phenomenon whereby cells migrate to the organ of their origin. By homing, transplanted hematopoietic cells are able to travel to and engraft (establish residence) in the bone marrow. Various chemokines and receptors are involved in the homing of hematopoietic stem cells.
59
engraftment
Engraftment is when the blood-forming cells you received on transplant day start to grow and make healthy blood cells.
60
scaffold types
-monolithic -microporous -nanoparticles -fibrous -hydrogel network -3D printed
61
Biophysical Bulk characterisitics
- viscoelasticity -stifness -degradation
62
Biophysical Surface characterisitics
-guidance -shape and size -roughness -charge -wetting
63
Biochemical characterisitics
-chemical structure -adhesion ligands -cytokines, antigens, growth factors -minerals -anti-infalammatory agents -reprogramming factors -spatio-temporal representation
64
Metods for generation od reactive groups on the surface
plasma treatment chemical etching pre-functionalized polymer
65
Biomaterials physical forms
fibers meshes foam particles tubular