Session 1: Basic Concepts

Question 1

regenerative medicine

Answer 1

it is the process of replacing, engineering, or regenerating human cells, tissues, or organs to restore or establish normal function

Question 2

tissue engineering

Answer 2

an interdisciplinary field that applies engineering and life sciences principles to develop biological substitutes that restore, maintain, or improve tissue function

Question 3

what does tissue engineering help us understand better

Answer 3

it helps us understand the functional principles of tissues at different levels of organizations

Question 4

regeneration

Answer 4

the process wherby lost specialized tissue is replaced by proliferation of undamaged specialized cells, thought to be limited in humans to a few tissues

Question 5

repair

Answer 5

the replacement of lost tissue by granulation tissue by granulation tissue which matures to form scar tissue, but doesn’t fully restore normal tissue structure & function

Question 6

who is in charge of the approval of these products derived from tissue engineering and how are they regulated?

Answer 6

in the EU they are regulated and approved by the EMA(European Medicines Agency), through its Committee for Advanced Therapies and the Committee for Medicinal Products for Human Use
these products are considered as ATMPs (advanced therapy medicinal products)

Question 7

how can atmps be classified

Answer 7

• gene therapy medicines
• somatic-cell therapy medicines
• tissue-engineered medicines

Question 8

combined atmps

Answer 8

they are atmps that contain one or more medical devices as an integral part of the medicine

Question 9

gene therapy medicines

Answer 9

contain genes that lead to a therapeutic, prophylactic or diagnostic effect

Question 10

somatic-cell therapy medicines

Answer 10

contain cells or tissues that have been manipulated to change their biological characteristics or cells or tissues not intended to be used for the same essential functions in the body; can be used to cure, diagnose, or prevent diseases

Question 11

tissue-engineered medicines

Answer 11

contain cells or tissues that have been modified so they can be used to repair, regenerate or replace human tissue

Question 12

what is a cell

Answer 12

the smallest structural and fucntional unit of an organism, which is typically microscopic and consist of cytoplasm and nucleus enclose in a membrane

Question 13

how do we know them?

Answer 13

throughout their behavior or function, which is shown as specific genes or proteins active

Question 14

how many cell types exist

Answer 14

there are around 215 types of cells, among differentiated and stem cells and 4 types of tissues; each tissue is formed with a collection of specific cells

Question 15

what are some cell type examples

Answer 15

fibroblasts, myoblasts, cardomyocytes, red blood cells, endothelial, neurons, hepatocytes, osteocytes, somatic, IPS, embryonic

Question 16

stem cell

Answer 16

an undifferentiated cell of a multicellular organism which is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cell arise by differentiation

Question 17

what is the potency of a stem cell?

Answer 17

a measure of how many types of specialized cells a stem cell can make

Question 18

what is cellular differentiation?

Answer 18

the process where a cell changes from one cell type to another; usually the cell changes to a more specialized type

Question 19

stem cell to cellular potency

Answer 19

oocyte and sperm -> totipotent cell
blastocyst -> pluripotent cell
ectoderm/mesoderm/endoderm -> multipotent cell
neuron & epithelial cells/RBC & cardiomyocytes/liver & pancreas -> unipotent cell

Question 20

what is a cellular lineage

Answer 20

it regard the developmental history of a differentiated cell as traced to the germ layer from which it arises and ends up in its mature phenotype

Question 21

what are the three germ layers of the tri-laminar disk?

Answer 21

• ectoderm(outermost layer): epidermis, nervous, hair
• mesoderm(middle layer): blood, bone, muscle, cartilage
• endoderm(innermost layer): internal systems, mucosa membrane linning, glads, epithelium

Question 22

what is the stem cell niche

Answer 22

specific anatomic location of a tissue that provides a specific microenvironment, in which stem cells are presen in an undifferentiated and self-renewable state

Question 23

what is the cellular fate?

Answer 23

describes its future identity, or the identity of its daughter cells, before it is actually phenotypically detectable through differentiation or division

Question 24

what is a cellular plasticity?

Answer 24

refers to the ability of some stem cells to give rise to cell types, formerly considered outside their normal repertoire of differentiation for the location where they are found

Question 25

how do cells grow?

Answer 25

by mitosis in the cellular cycle

Question 26

how often do cells grow?

Answer 26

it is a function of the cues of the microenvironment; cell division can be stopped due to space, chemical factors, etc.

Question 27

Hayflick Limit

Answer 27

maximum number of times a cell can divide due t telomer shortening is 30-50, its an aging mechanism that provides protection

Question 28

Apoptosis

Answer 28

a pathway of cell death induced by a tightly regulated suicidal program, to keep in balance the development and growth of organisms, crucial in homeostasis, morphogenesis, and avoidance propagation of damaged cells

Question 29

significance and characteristics of apoptosis

Answer 29

• is crucial for survival of multi-cellilar organisms as cell division
• plasma membrane unbroken
• cellular content encapsulated in apoptotic bodies
• loss of mitochondrial membrane
• nuclear envelope disassembles
• cytoskeleton collapses
• DNA breaks into fragments

Question 30

necrosis vs apoptosis

Answer 30

• un natural | natural
• detrimental | beneficial
• always pathological | physiological or pathological
• energy independet | energy dependent
• parts of tissue | single cells
• cellular breakdown | cellular fragmentation
• no membrane integrity | membrean integrity

Question 31

primary cells

Answer 31

cells isolated directly from human or animal tissue using enzymatic or mechanical methods; once isolates, they are place in artifical evironment in plastic or glass containers supported with specialized medium containing essential nutrients and growth factors to support proliferation

Question 32

cell lines

Answer 32

a permanently established cell culture that will proliferate indefinitely given appropriate fresh medium and space; lines differ from primary cells in that they have escaped the Hayflick Limit and become immortalized

Question 33

autologous

Answer 33

patients own cells; not available off-the-shelf; immune acceptable

Question 34

what are the possible origins of cells

Answer 34

autologous, allogenic, xenogenic

Question 35

allogenic

Answer 35

cells from other human sources; available off-the-shelf; require engineering immune acceptance; be concerned with virus transmission

Question 36

xenogenic

Answer 36

cells from different species; available off-the-shelf; requires engineering immune acceptance; be concerned with animal virus transmission

Question 37

in vitro tissue engineering

Answer 37

involves the manipulation of cells, biomaterials and tissue construcs in vitro, prior to implantation into the in vivo environment

Question 38

in vivo tissue engineering

Answer 38

relies on the body’s natural ability to regenerate with the help of implanted biomaterials and cells