Flashcards in Final Deck (20):
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
List the different classes of biomaterials
Metals, Ceramics, Polymers, Composites
Scheme 2: Synthetic, Natural
Compare and contrast the molecular make-up, microstructure, properties of metals, ceramics and polymers
-micro: aligned crystal packs in grains. 1-1000 microns
-strong, ductile, conducting, high MP, high density, reflective, ductile/malleable
-also pack into crystal structures 1nm-100 micron. smaller than metals
-insulators, stiff, high MP, brittle, lustrous, lubricious, polishable
-network of entangled or cross linked chains of repeating monomer
On a stress/strain curve, draw curves of an ideal ceramic, metal and polymer.
(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+)
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.
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.
What is the difference between stealth and bioactive biomaterials?
-attempt to avoid bodily response
-Prevent protein absorption, innate immune reactions and clotting
-Stimulates specific biological cascads to achieve desired goal
-goals could be:
improved integration and biocompatibility
activation or inactivation of immune system
Describe how blood clots work (3 primary arms and make up of final clot)
1. Blood Vessels
-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.
What type of device accelerates clotting? How does this device function?
Wound closure (adhesives, sutures, staples)
Clotting agents (collagen, firbinogen, thrombin)
Describe how we prevent blood from clotting in storage?
Chelators that prevent Ca2+ from allowing the cascade to continue (EDTA/ Citrate)
Describe 3 consequences of adhesion of blood proteins to biomaterial surfaces
Clotting, heart attack, stroke, pulmonary embolism, occlusion of catheters and shunts
What is meant by wound healing?
Process of tissue repair
-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
How does the foreign body response differ from normal wound healing
persistent inflammation and formation of scar tissue (firbrous encapsulation)
Provide a diagram to explain the process of indirect immunohistochemistry
what is meant by the term "cell type specific biomarker"?
marker found in only the cell type of interest
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
Describe the 3 types of regenerative medicine approaches
-harvested cells from tissues and organs are injected into new patients. usually protected from immune system by barrier/membrane
- placing cells inside of a biomaterial that only allows access at certain places and in certain conditions in the body
-harvested cells, scaffolding, conditioning
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
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