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Flashcards in Unit 4 Deck (49)
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1
Q

Name an advantage and disadvantage for tissue engineering of organs / tissues?

A

Advantages: No donor/self-donor tissue limitations, function restored for pt lifetime

Disadvantages: biological complexities of complete organ regeneration unsolved, possible immune response depending on cell source

2
Q

Name a place where adult stem cells can be found?

A

Bone marrow

(stem cells are tissue specific)

3
Q

State and describe 2 components of any basic tissue engineering design

A

Scaffolding

  • acts as ECM for cells, defines formation and guides development of cells
  • must control structure and function of tissue in a predesigned manner
  • must degrade at rate proportional to new tissue regrowth

Bioreactor

A system where conditions are closely controlled to permit and induce a certain behavior in living cells or tissues

4
Q

Describe the steps involved in any tissue engineering project

A
  1. cell source isolates and cells produced in sufficient numbers
  2. Biocompatible material identified to be used as a cell substrate, material manufactured into desired shape and dimensions
  3. Cells seeded onto/into material while maintaining function and morphology
  4. Engineered structure placed into appropriate in vivo sites
5
Q

Distinguish between embryonic stem cells and adult stem cells

A

Embryonic: found in embryos, have not committed to a certain type of tissue, responsible for embryonic and fetal growth. thought to be able to differentiate into all cells of body

Adult: responsible for growth, tissue maintenance and regeneration, found in adult tissue and specific to that tissue

6
Q

Give two disadvantages of organ transplants

A

Disadvantages:

possible immune response depending on cell source

biological complexities of complete organ regeneration unsolved

7
Q

What are the advantages of surface modification of biomaterials?

A

Surface moddification keeps the bulk material the same while changing the surface in order to influence biocompatibility and other performance parameters.

8
Q

State three functions of scaffolds?

A

Delivery of cells to desired sites

Guide development of cells

Define space for formation

9
Q

Name three requirements for scaffolds for tissue engineering

A
  1. Biocompatible
  2. biodegradable at the correct rate
  3. Mechanical properties that are consistent with tissue they are replacing
10
Q

Define bioreactor

A

A system in which conditions are closely controlled to permit or induce certain behavior in living cells or tissues.

11
Q

Define tissue engineering.

A

In vitro development of tissues or organs to replace or support the function of defective or injured body parts or the directed management of the repair of tissues within the body.

Strategies employed to develop biological substitutes that restore, maintain, or improve tissue function by differentiation of cells to ultimately develop cells into functional tissue

12
Q

Describe spinner flask bioreactor

A

Scaffold suspended at one end at needles. magnetic stirrer mixes media while scaffold remains fixed

13
Q

What are the requirements of scaffolds?

A

Desired surface properties to enable cell attachment, growth proliferation & differentiation as well as ECM formation

Have optimum architectural properties to allow proper connectivity, delivery of efficient nutrients, and proper removal of waste

Be able to be reproduced and easily processed into 3-D shapes

14
Q

What is stent restenosis?

A

major failure mode of stent: renarrowing of an artery at the stenting site

15
Q

Name three requirements for a potential stent material

A

Rigid for support, Radial flexibility for insertion, appropriate dimensions, ability to deliver therapeutic agents( specific)

16
Q

What is a pacemaker?

A

Regulates beating (maintains adequate HR) of the heart by delivery of electrical impulses from electrodes contacting the heart muscle

17
Q

Name 3 cardiovascular medical devices

A

pacemaker

stent

Ventricular assist device

18
Q

Describe the process of inserting a stent in a coronary artery

A

PTCA: percutaneous transluminal coronary angioplasty

  1. insertion through catheter
  2. Centered at site of plaque buildup
  3. Expansion of stent by inflating balloon which is on inner portion of collapsed stent
  4. Deflating balloon after stent has expanded
  5. removing catheter and deflated balloon, leaving stent
19
Q

What is the primary purpose of a pacemaker?

A

Maintain an adequate HR (usually keep it from being too slow)

20
Q

What is a Ventricular Assist Device ?

A

A mechanical blood pump system that connects a ventricle to a vessel, has an internal(for long term) or external (for short term) pump and an external motor. Used for people who have weak hearts and need help pumping blood through body.

Process: tube carries blood out of heart into pump, another tube carries blood from pump into blood vessels which then deliver blood to body

21
Q

What important function must a prosthetic hearts perform?

A

?

22
Q

Give two pros and cons for the following heart valve designs: mechanincal, and bioprosthetic

A

Mechanical:

advantages: Durability, lifespan >25 yrs
disadvantages: Risk of thrombosis, long term anticoagulation therapy

Bioprosthetic:

advantages: Do not require anticoagulation therapy, lower risk of thrombosis
disadvantages: lifespan of 10-15 yrs, progressive risk of valve deterioration

23
Q

State the four criterion for patient selection for use of an AbioCor artificial heart

A
  1. have end-stage heart failure
  2. Have a life expectancy of less than 30 days
  3. not eligible for a natural heart transplant
  4. Have no other viable treatment options
24
Q

Briefly describe with diagrams the anatomy and working of the heart.

A
25
Q

State and describe two devices that are used for the management of congestive heart failure

A

LVAD: left ventricular assist device: a mechanical blood pump that helps a weak Left ventricular muscle pump blood through the body. A tube carries blood from LV to pump, another tube carries blood from pump to vessel, from vessels it is distributed through body.

Intra Aortic Balloon Pump -IABP: A balloon is inserted into body through catheter, Inflation and deflation of balloon synched to hearts pumping action. Balloon supports heart indirectly by augmenting blood flow

26
Q

Describe two mechanical heart valve designs

A

Mechanical heart

  • Caged Ball
  • metal cage with ceramic or polymer ball
  • one way blood flow, if blood tries to go other way, ball occludes vessel

bi-leaflet

  • one way blood flow
  • titanium used for main housing
  • pyrolytic carbon used for leaflets and inner ring (material prevents clotting)
  • polyester (Dacron) used for suturing valve to heart
27
Q

Describe rationale for undergoing a total hip replacement surgery?

A

Reducing hip pain and improve motion at hip

28
Q

What are the causes that necessitate total hip replacement surgeries.

A

caused by osteoarthritis, osteoporosis, injury, bone tumor

29
Q

State and describe the various hip replacement devices currently available.

A

Current hip replacements have cup and liner at acetabular component, a stem and neck at femoral component, and a femoral head.

Types

  • Metal-Metal (metal cup, metal ball)
  • Metal-on-polyethylene (Poly cup, metal ball)
  • ceramic on polyethylene (poly cup, ceramic ball)
  • ceramic on ceramic (cup and ball)
30
Q

What are the benefits of using a ceramic-on-ceramic hip implant?

A

Best for active patients because it is reliable and lasts a long time, low wear rate, No inflammation or bone loss

31
Q

State two orthopedic medical devices.

A

Total knee replacement devices

Spinal implants

32
Q

Describe medical devices related to total knee replacement

A

A hinge prosthetic joint with 3 components

Femoral component

Tibial

articulating layer which is usually a polymer

Fixed bearing v. mobile bearing

cement v. cementless implants

33
Q

Describe medical device related to spinal implants

A

Fusion v. non fusion Fixation Devices

Fusion: uses synthetic bone substitutes like scaffolding, bone grafting, or combinations with metallic components.

Fixation: faceting together vertebrae by non fusing, uses metallic components through vertebral bodies or outside of bodies

34
Q

What are the common complications / issues that arise after total hip replacement surgeries?

A

Dislocation, ball can come out of socket.

Osteolysis: loosening of implant bc of polyethylene wear debris

Metal sensitivity due to metal debris

35
Q

What are the common complications / issues that arise after knee replacement

surgeries?

A

Loosening/ fx of the device components, dislocation/instability, misalignment, bone fx, swelling and joint pain, infections, osteolysis

36
Q

State two conditions that may require spine surgery

A

Spinal Stenosis: narrowing of spinal foramen

Scoliosis

37
Q

State and describe the two major categories of spinal implant devices

A

Fusion devices: joining of 2 or more vertebrae using bone tissue from a pt or donor into a single fused vertebrae component

Fixation Devices: fixation of vertebrae without fusion due to injury or dislodging. For example, use of rods/plates/screws external of vertebral body

38
Q

Name an alloy that is preferred for use in dental applications for root implants?

A

Ti6Al4V

39
Q

Describe challenges of traditional drug delivery.

A

Lack of control on drug distribution in the body, biological effects on drug, hard to used for advanced therapeutic methods since drug level in the body decreases with time

40
Q

What is the purpose for use of a dental brace

A

Dental braces correct flaws of teeth and jaw, to straighten and align them

41
Q

State two requirements of a potential material for its application as a dental brace

A

Aesthetic Performance

Mechanical Performance

Corrosion resistance

42
Q

What is the difference between a visual prosthesis and an ocular prosthesis?

A

Visual prosthesis is a bionic eye intended to partially restore lost vision or amplify vision

Ocular prosthesis: artificial eye that replaces a natural eye’s position but does not increase vision

43
Q

What is a cochlear implant, how does it work?

A

a surgically implanted device what helps profoundly deaf or severe HOH pt’s overcome problems in the inner ear/cochlea. “bionic ear”

Uses a microphone to pick up sound which is sent to a speech processor, sound is converted to electrical signal and signal is eventually sent through nerve endings in cochlea and along hearing nerve to brain for interpretation

44
Q

What are the two primary type of contact lenses.

A

soft lenses

rigid gas permeable lenses

45
Q

What are the functions of dental sealants?

A

Effective in preventing tooth decay in the pit and fissure areas of the teeth

46
Q

State and describe three ethical issues in development of new biomaterials.

A

?

47
Q

What are intraocular lens and why are they used?

A

Intraocular lenses are implanted into the eye and are usually used as a solution to cataracts

48
Q

Define Biosensors

A

Any device that uses specific biochemical reactions to detect chemical compounds in biological samples. The device quantifies the information so it can be sent to detector for analyzation

49
Q

State and briefly describe the components of a biosensor

A
  1. analyte: what is being specifically detected
  2. sample handling: delivering the analyte to the desired region
  3. Detection/recognition: specifically recognizing the analyte
  4. signal: detecting the analyte
  5. detector