Questions cluster 1, 2 Flashcards
From which embryonic structure are embryonic stem cells (ESCs) derived, and are they totipotent or pluripotent? Motivate your answer.
Inner cell mass
Pluripotent
ESC can form all structures in the embryo but not extra-embryonic tissues.
which endothelial progenitor cell type is thought to become a structural part of newly formed blood vessels?
a) Colony-forming units (CFU) -Hill cells
b) Circulating angiogenic cells (CAC)
c) Endothelial colony-forming cells (ECFC)
d) All of the above
c) Endothelial colony-forming cells (ECFC)
What is the difference between angiogenesis and vasculogenesis?
Angiogenesis: formation of new blood vessels (capillaries) from pre-existing vessels
Vasculogenesis: formation of new blood vessels de novo (without pre-existing vessels)
How can you prove stemness of adult hematopoietic stem cells?
Serial transplantation of bone marrow cells into irradiated mice, and showing that they are capable of forming all blood cell lineages.
Epithelial organoid cultures have been derived from many tissues of murine and human origin. Name three of these tissues.
Possible answers: (o)esophagus, colon & rectum, liver, pancreas, salivary gland, skin (epidermis), small intestine, stomach, taste buds, fallopian tube, mammary gland, prostate, lung
Which is the first cell type involved in foreign body response?
a) M1 macrophages
b) M2 macrophages
c) Neutrophils
d) Complement system
c) Neutrophils
What is an unfavorable side effect of decellularization on tissue?
An unfavorable side effect of decellularization is the loss of important biological/bioactive/structural/functional components that reside in the ECM.
What is the main difference between physically and chemically crosslinking methods for hydrogels?
Physical crosslinking: physical bonds are formed (hydrogen bonds, hydrophobic interactions)
Chemical crosslinking: covalent bonds are formed.
What is a supramolecular polymer? Give the definition.
A supramolecular polymer is a polymeric array of monomeric units that are brought together by reversible and highly directional non-covalent interactions, resulting in polymeric properties in dilute and concentrated solution as well as in the bulk.
Name 3 types of bioink.
Gelatin, collagen, alginate, matrigel, hyaluronic acid, decellularized ECM, PEG
Which of the following statements on additive manufacturing technologies is correct?
a) Stereolithographic printing requires the use of shear thinning bioinks
b) The first patented 3D printing technology was fused deposition modelling
c) In fused deposition modelling, a metal filament is melted through a hot end end extruded to build 3D objects
d) Stereolithography prints objects at a slower speed than digital light projection, but provides higher resolution
d) Stereolithography prints objects at a slower speed than digital light projection, but provides higher resolution
Why is healing of cartilage defects so ineffective? Name two reasons.
No direct delivery of nutrients through blood vessels
Few active cells present to produce matrix
Compact matrix which does not allow quick cell migration
What is the main function of the allogeneic MSCs that are combined with autologous chondrons in the IMPACT trial to treat cartilage defects?
a) they differentiate into chondrocytes and produce cartilage tissue
b) they stimulate the autologous cells to produce new cartilage tissue
c) they modulate the inflammatory response
d) they transdifferentiate into adipocytes to provide lubrication
b) they stimulate the autologous cells to produce new cartilage tissue
Name two components that maybe present in extracellular matrix. Briefly describe their roles in the mechanical properties of tissue.
- Glycosaminoglycans, proteoglycans (e.g., hyaluronan, chondroitin sulfate, dermatan sulfate, heparin sulfate, keratin sulfate): ground substance for ECM, ‘space filler’, resist compressive loading
- Structural/fibrous proteins (e.g., collagen, elastic fibers/elastin, fibrin): strengthen, organize ECM, maintain ECM integrity, high stiffness
- Glycoproteins (e.g., fibronectin, laminin): facilitate cell attachment/adhesion, organize ECM by facilitating adhesion between various ECM components.
What does it mean when a material is anisotropic?
A material is anisotropic when the material properties depend on a direction. This means that if we extract a tissue sample from a piece of material and subject it to a uni-axial stress test, the result depends on the original orientation of the sample in the material. Biological materials are often anisotropic because they contain a large number of highly oriented fibres.