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Flashcards in Final Deck (20):
1

What is a biomaterial?

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

List the different classes of biomaterials

2 Scheme's

Scheme 1:
Metals, Ceramics, Polymers, Composites

Scheme 2: Synthetic, Natural

3

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

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

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

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

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

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

Define what is meant by the term biocompatibility

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

7

What is the difference between stealth and bioactive biomaterials?

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

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

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

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

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

10

Describe how we prevent blood from clotting in storage?

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

11

Describe 3 consequences of adhesion of blood proteins to biomaterial surfaces

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

12

What is meant by wound healing?

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
4. wound remodeling

13

How does the foreign body response differ from normal wound healing

persistent inflammation and formation of scar tissue (firbrous encapsulation)

14

Provide a diagram to explain the process of indirect immunohistochemistry

DIAGRAM

15

what is meant by the term "cell type specific biomarker"?

marker found in only the cell type of interest

16

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

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

Describe the 3 types of regenerative medicine approaches

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

Describe the 3 components of the tissue engineering triad

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

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

Limited to no fibrous encapsulation (scarring)
Go evidence of FBGCs

20

Describe the major events in wound healing sans implant

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