Biomat Final

regeneration

term that best represents the future of biomaterials science

biocompatibility

the ability of a material to perform in a specific application with an appropriate host response

10 nanometers

The thickness / depth of what we describe as the ‘surface’ is closest to

protein adsorption

There are few if any mechanisms for bio-recognition between synthetic materials and our cells, therefore cell / material interactions are dependent upon

cohesive forces

The tendency of water to ‘bead up’ and roll off Teflon reflects a preponderance of

surface area

Surface tension is a measure of the amount of energy / work required to increase the ______ of a liquid

surface free energy

Titanium has a higher _____ than polyethylene

ysv = ysl + ylvcos

Young’s equation

work of adhesion

the _____ between an oil droplet and polystyrene is higher than between a water droplet and glass

number

Gecko adhesion derives from the_______________ of intermolecular interactions with the surface

kinetic energy proportional to binding energy

In ESCA / XPS-we are applying the photoelectric effect. What data is being directly measured using an XPS instrument and how is this data used to determine atomic percent composition?

electrons

XPS is surface sensitive because only _____ released near the surface are able to escape

secondary electron

______________ imaging in SEM provides the highest resolution image of surface feature

backscatter

____________ imaging in SEM is best suited for generating contrast as a function of chemical composition

depth of field and resolution

SEM is superior to light imaging in

quantitative

AFM imaging provides _____ information about the height of surface features

hydrated

AFM imaging works well in a ____ environment

collagen

The most abundant protein in the extracellular matrix is

integrin, RGD amino acids

Cell adhesion in normal tissue is mediated primarily by binding between _____________ receptors and specific cell adhesion proteins having ____________

polyelectrolyte

alternative/opposite charges for layering, ionizable and water soluble are characteristics of

gas, increase, amount

For a standard hydrocarbon plastic like polystyrene, treatment with plasma, an high energy, ionized __________________ is expected to (increase / decrease) wettability and change the (amount / identity) of adsorbed proteins

initiation

step in free radical polymerization

propagation

step in free radical polymerization

termination

step in free radical polymerization

linear model

The molecular weight as a function of time in a free radical polymerization can best be represented by a

reduce highly ordered water molecules

‘hydrophobic interactions’ energetically favorable

nonpolar

Protein folding tends to internalize amino acids with (polar / nonpolar) side chains

protein function

The resulting 3D ‘conformation’ is essential to ____

increase in entropy

What is the thermodynamic change that makes protein adsorption a spontaneous process

nonpolar

Protein adsorption to a (polar / nonpolar) surface is most likely to cause large changes in the protein structure / conformation

fold

after translation, proteins _____ into a 3D conformation that is essential to their bioactivity

sensitivity

relative to absorbance or fluorescence for measuring protein adsorption, radiation offers superior ____

antibody

Which class of ‘receptor’ exhibits the highest binding affinity?

Integrin

Which class of ‘receptor’ can change its binding affinity?

Adsorption

Factor XII is activated by

fibrinogen

Which protein helps bind / crosslink platelets together to form a platelet plug

thrombin

Factor XIII is activated by ____

proteases

enzymes responsible for the cleavage of other proteins

sub endothelial cells

Tissue Factor normally resides in

intrinsic

Which part of coagulation pathway poses a greater long-term challenge

calcium

Which ion plays a key role in the coagulation process?

endothelial damage and dilution

What are two characteristics of how the clotting process works that help ensure it occurs ‘locally’ rather than systemically

heparin

Anti-thrombin III forms a complex with __________________ that inhibits many upstream steps of the coagulation process

tissue plasminogen activator (TPA)

When we think about the breakdown of fibrin clots, the rate limiting component in generating plasmin is:

clotting factor activity

Coumadin / warfarin primarily interferes with

extrinsic

The prothrombin time (PT) test provides insight into the activity of the __________________ component of the coagulation system

thrombus

a pathological blood clot that develops on an implant surface

catheters and bio sensors

Besides blood-contacting medical devices, what are 2 other applications where non-fouling surfaces are highly desirable?

osmotic and entropic repulsion

PEG is particularly effective at making surfaces resistant to protein adsorption through

increase half life and decrease immunogenicity

two benefits of modifying a therapeutic by PEGylation

drug, biologic, device

The 3 classes of FDA-regulated medical products are

polysaccharide

Heparin is a

layer by layer and covalent grafting

2 surface modification techniques (not product names) that have been used to apply heparin to biomaterial surfaces

measure aTIII, platelet adhesion, fibrin deposition

Once a material has been modified with heparin and the presence of heparin confirmed, what are three things that might be measured to verify the bioactivity of the heparin coating?

adjacent tissue and environmental sterilization

What are two potential sources of bacteria that can initiate device-centered infection

blocks immune response and inhibits diffusion

2 mechanisms by which a biofilm hinders the efficacy of antibiotics

biofilm

key distinction between acute and chronic periprosthetic joint infection is the maturity of the ___________

silver

a metal widely incorporated into materials and devices to provide anti-microbial resistance

water and CO2

Upon subsequent metabolism-these degradation products will ultimately be eliminated from the body as

ester

PLGA and poly(lactide) are both members of the poly __________ family of polymers

Innate

The foreign body response is primarily attributable to _________ immunity

FBGCs

multi-nucleated cells observed at the interface of synthetic material implants

fibroblasts, collagen

Fibrous encapsulation involves what cell type (____________) and what is the major ECM component they are producing (___________)

blocking readings and effect device performance

example of how fibrous encapsulation might adversely affect performance of a device or therapeutic transplant

acute inflammation

an essential part of all healing processes

cytokines/growth factors

What type of stimulus is usually used to direct such naïve cells to differentiate into M1 or M2 phenotype?

surface markers/transcriptional profile

what characteristic of the cells could you use to verify that your study was successful, i.e. that your naïve macrophages have in fact transformed into M1 macrophages?

chronic inflammation, fibrosis

pathological consequence might one expect from prolonged / excessive activity of:

a. M1 macrophages

b. M2 macrophages

VEGF

initiates angiogenesis and activates endothelial cells, branches

PDGF

recruits pericytes, secrete collagen and stabilize nascent vessels

M2/M1 macrophage ratio

Dr. Bellamkonda’s paper: nerve regeneration closely corresponds to

mechanical loading

Bone undergoes constant remodeling. The most important factor external factor in controlling this process

osteoclasts

cells that degrade existing bone

osseointegration

the attainment of “direct structural and functional connection between bone and the surface of an artificial implant

titanium

dental implants are composed of alloys, the major metallic component is

sandblasting, acid etching

SLA surface modification combines __________________________ and __________________________ to create surface roughness

anodization

positively charged metallic atoms are extracted from the implant, while negatively charged oxygen atoms are attracted to and chemically react with the surface of the implant

biomimetic

Performing surface modification that produces features consistent with resorption pits is an example of __________________________ design principles

sterilization, manufacturing, regulatory approval

physical surface modification is most amendable to

crosslinked water soluble polymer

a hydrogel is

lower toxicity, higher viscosity

two advantages of macromonomers / macromers relative to preparing a hydrogel from low molecular monomer and crosslinker

benefits: reproducibility, non immunogenetic limitations: lack of bioactivity, absence of cell adhesion

Relative to naturally-derived hydrogels: list 2 key benefits and 2 key limitations of hydrogels formed from synthetic biomolecules

collagenase

Once implanted in a patient, how will a collagen gel be degraded

gelatin

naturally-derived material can form thermo-reversible hydrogels

free radical groups added to gelatin

How is GelMA most commonly crosslinked?

increase, decrease

As the number of added reactive groups per naturally-derived macromolecule increases, how do mechanical properties and degradation rate change?

biological activity

Ideally, the degradation rate of an implanted hydrogel should be controlled by

emulsion

Hydrogel microparticle fabrication usually involves adding a relatively small volume of an aqueous solution containing hydrogel-forming material to a relatively larger volume of oil under stirring, for a W/O