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Flashcards in Final Deck (20)
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1
Q

What is a biomaterial?

A

Any material of natural or synthetic origin that comes in contact with tissue, blood, or biological fluids, and is intended for use in medicine

2
Q

List the different classes of biomaterials

A

2 Scheme’s

Scheme 1:
Metals, Ceramics, Polymers, Composites

Scheme 2: Synthetic, Natural

3
Q

Compare and contrast the molecular make-up, microstructure, properties of metals, ceramics and polymers

A

METALS

  • electron cloud
  • crystalline structure
  • micro: aligned crystal packs in grains. 1-1000 microns
  • strong, ductile, conducting, high MP, high density, reflective, ductile/malleable

CERAMICS

  • ionic/covalent bonding
  • also pack into crystal structures 1nm-100 micron. smaller than metals
  • insulators, stiff, high MP, brittle, lustrous, lubricious, polishable

POLYMERS
-network of entangled or cross linked chains of repeating monomer
-covalent bonds
-

4
Q

On a stress/strain curve, draw curves of an ideal ceramic, metal and polymer.

A

DIAGRAM

(Ultimate Strength MPa, Modulus GPa, strain at failure %)
Metals; 500-1000, 100-200, 10-20
Ceramics: 500-1000+,500-1000+ <1
Polymers (10-100, .1-1, 10-100+)

5
Q

Describe the general history and evolution of the use of biomaterials over time

A

Historic origins, implants in Egyptian legs, WWI, WWII incidental discovery that things that were not intended for use with the body, actually had good consequences. PMMA/nylon. Materials created specifically for medical purposes.

6
Q

Define what is meant by the term biocompatibility

A

Ability of a biomaterial to perform with an appropriate host response in a specific application. Device and application specific.

7
Q

What is the difference between stealth and bioactive biomaterials?

A

STEALH

  • Nonreactive
  • attempt to avoid bodily response
  • Prevent protein absorption, innate immune reactions and clotting

BIOACTIVE
-Stimulates specific biological cascads to achieve desired goal
-goals could be:
–Reduced clotting
improved integration and biocompatibility
healing
activation or inactivation of immune system

8
Q

Describe how blood clots work (3 primary arms and make up of final clot)

A
  1. Blood Vessels
    - vasoconstriction
  2. Platelets
    - promote vasoconstriction, adhere to collagen and plug site. release chemicals to recruit platelets and macrophages. stimulate repair of blood vessel
  3. Clotting Cascade
    - self amplifying cascade of proteins
    - converts fibrinogen to fibrin

Clots are made of a fibrin matrix and adhering platelets.

9
Q

What type of device accelerates clotting? How does this device function?

A
Wound closure (adhesives, sutures, staples)
Cautery
Clotting agents (collagen, firbinogen, thrombin)
10
Q

Describe how we prevent blood from clotting in storage?

A

Chelators that prevent Ca2+ from allowing the cascade to continue (EDTA/ Citrate)

11
Q

Describe 3 consequences of adhesion of blood proteins to biomaterial surfaces

A

Clotting, heart attack, stroke, pulmonary embolism, occlusion of catheters and shunts

12
Q

What is meant by wound healing?

A

Process of tissue repair

  • Restore Homeostasis
  • kill bacteria introduced into wounds
  • remove damaged or dead cells and debris
  • form new tisssue at site of injury
  1. restore homeostasis
  2. acute inflammation
    3, granulation tissue formation
  3. wound remodeling
13
Q

How does the foreign body response differ from normal wound healing

A

persistent inflammation and formation of scar tissue (firbrous encapsulation)

14
Q

Provide a diagram to explain the process of indirect immunohistochemistry

A

DIAGRAM

15
Q

what is meant by the term “cell type specific biomarker”?

A

marker found in only the cell type of interest

16
Q

How would you set up a study to examine the FBR to a new implant to be used in the brain?

A
  1. Choose animal and brain location
  2. Prepare implants as close to how they will be used clinically
  3. Perform surgery in a statistically appropriate number of animals
  4. Euthanize and collect tissue at meaningful time or function
  5. Analyze the impacted tissue implant
17
Q

Describe the 3 types of regenerative medicine approaches

A

Cell therapy
-harvested cells from tissues and organs are injected into new patients. usually protected from immune system by barrier/membrane

Smart biomaterials
- placing cells inside of a biomaterial that only allows access at certain places and in certain conditions in the body

Tissue engineering
-harvested cells, scaffolding, conditioning

18
Q

Describe the 3 components of the tissue engineering triad

A

Cells (stem/diff) (Auto/allo/xeno: patient’s cells/ same species/different species)

Scaffolding: need a structure to help the cells grow into the correct form

Conditioning: prepping the cells for implant. nutrients, gas, waste removal, growth factors, mechanical factors

19
Q

What is the primary advantage of ECM materials over traditional synthetic scaffolds for regenerative medicine?

A

Limited to no fibrous encapsulation (scarring)

Go evidence of FBGCs

20
Q

Describe the major events in wound healing sans implant

A
  1. Blood Vessel Damage
  2. Restoration of Hemostasis
    - vasoconstriction, platelets,
  3. Acute Inflammation
    - complement activation, macrophage recruitment
  4. Granulation tissue formation
    - ECM and new blood vessel tissue grow
  5. Wound remodeling