BE 201

Question 1

what generates all types of the cells in the body

Answer 1

Totipotent cells

Question 2

what can tissue engineering do

Answer 2

cell expansion and manipulation
cell seeding and extracellular matrix expression
full incorporation into host
cell sourcing

Question 3

diseases that could be treated with tissue engineering

Answer 3

cancer, tobacco smoker lungs, polycystic kidney,

Question 4

a graft of tissue from one point to another of the same individual’s body

Answer 4

Autograft

Question 5

a graft of tissue from one individual to another individual of the same species who is not an identical twin

Answer 5

Allograft

Question 6

a tissue graft transplant from a donor of a different species from the recipient

Answer 6

xenograft

Question 7

limitation of these current therapies

Answer 7

Lack of suitable harvest sites
Tissue rejection, transmission of disease, ethics
materials subject to fracture, fatigue, toxicity, and wear

Question 8

Graft

Answer 8

tissue from one site place on another site,
cost, likelihood of rejection, ethics
examples; bone , skin, lymphocytes, organs

Question 9

cell-based

Answer 9

cellular therapy,seeks to repair damaged and diseased tissues by transplanting healthy new cells to the affected site

Question 10

scaffold-guided

Answer 10

seeding a porous biodegradable scaffold with donor cells and or growth factors, then culturing and implanting the scaffold to induce and direct the growth of the new tissue. The goal is for the cells to attach to the scaffold, replicate and ultimately grow into healthy, functioning tissue as the scaffold degrades

Question 11

Bioactive molecule-based

Answer 11

utilizes regulatory molecules, also known as growth factor, to induce and direct cell growth and differentiation

Question 12

what is true about ECM

Answer 12

A. ECM is collected of extracellular molecules that are secreted by the cells themselves.
B. It provides physical or structural support to the cells
C. It provides biochemical molecules to the cells

Question 13

ECM function

Answer 13

structural support, biochemical support, cell adhesion, cell to cell communication an differentiation

Question 14

proteoglycans

Answer 14

glycosaminoglycans + carbohydrate attached to proteins
- charged
-trap water molecules to keep the ECM and cells hydrated
- trap molecules that are essential for normal cell activities

Question 15

collagen

Answer 15

-most abundant protein in the ECM
-human body accounts for 90% of bone matrix protein content

Question 16

3D scaffolds

Answer 16

-provide mechanical stability
-deliver therapeutic agents
-facilitate processes critical in tissue repair

Question 17

3D scaffolds

Answer 17

natural materials
-collagen gel, alginate, agarose,decellularized tissue
synthetic materials
-freeze drying, porogen leaching, electrospinning, 3D printing

Question 18

3D Scaffold

Answer 18

Non-toxic
biocompatible or even bioactive
biodegradable - depends
mechanical properties
surface properties
porosity, pore size
Pore interconnectivity
internal architecture
active or static

Question 20

porosity

Answer 20

Vv/Vt
Vv= volume of void-space
Vt= total or bulk volume of the material

Question 21

grafts vs implants

Answer 21

Grafts contain cells
Autograft
Allograft
Implants do Not contain cells

Question 22

Bone Autografts

Answer 22

Harvested from a donor site in a patient

Question 23

osteoconduction

Answer 23

the property by which a graft supports the attachment of new osteoblasts and osteoprogenitor cells

Question 24

osteoinduction

Answer 24

the induction of osteoprogenitor cells to differentiate down an osteoblast lineage

Question 25

Bond Allografts

Answer 25

-Eliminates the need for a second surgical site -not necessarily immuno-privileged -

Question 26

Bone TE

Answer 26

-soft tissues heal exclusively by scar tissue formation -The smallest size intraosseous wound in a particular bone and species of animal that will not heal spontaneously during the lifetime of the animal

Question 27

Design Criteria

Answer 27

Non-toxic osteoconductive , osteoinductive biodegradable non- invasive

Question 28

size of the problem

Answer 28

American with arthritis second to heart disease cause of disability among american over age 15

Question 29

Articular cartilage

Answer 29

- Avascular -little ability of self-healing -tissue has solid ECM component and fluid phase -chondrocytes:specialized phenotype, which is lost with expansion in monolayer culture -low friction, weight-bearing, transmit high stress associated with joint motion

Question 30

chondrocytes

Answer 30

limited supply aged chondrocytes are less able to form functional constructs in agarose culture must be isolated from the joint tissue itself

Question 31

MSC chondrogenesis

Answer 31

high density culture, pellet culture

Question 32

purpose of skin

Answer 32

-barrier to foreign pathogens -regulating body temperature - preventing dehydration -providing sensation

Question 33

allografts as a temporary fix

Answer 33

usually from cadavers always rejected

Question 34

alternatives

Answer 34

cultured autologous keratinocytes or bioengineering skin substitutes -Bilayer structure -Permeable to moisture and not to water -Lower layer that acts as skin regeneration template

Question 35

Ideal properties of bioengineered skin so far is not available

Answer 35

. Non-Toxic, non immunogenic . No risk of disease transmission · Biodegradable Similar physical and Mechanical Properties to real skin Able to support reconstruction of normal tissue . Provide pain relief . Prevent fluid and heat loss and infection · Cost-Effective, available, good shelf life

Question 36

integra Dermal regeneration template

Answer 36

no living components two layers - matrix of collagen and GAG, and a flexible silicon sheet purpose : protective covering and scaffold for regeneration

Question 37

Dermagraft

Answer 37

cryopreserved human fibroblast-derived dermal substitute for advanced treatment of diabetic foot and leg ulcers

Question 38

Spray on skin

Answer 38

patented skin culturing treatment for burns victims, developed by plastic surgeon

Question 39

still a long way to go

Answer 39

lacks hair follicles sweat glands dendritic cells