L7 Flashcards
What makes up the microenviroment?
Other cell types
Growth factors
ECM proteins
What does the ECM provide?
Signaling via adhesion molecules on ECM fibers binding cell receptors (integrins)
Mechanical support - influences behavior
What do organoid protocols focus on?
Signalling cues
What does signalling through growth factors do?
Signalling at defined times essential to inducing necessary cell types
What are 2 current approaches of ECM supports?
No support matrix
Animal-derived support matrix
What is the future approach of ECM supports?
Organoid encapsulated in ECM mimic
What is a biomaterial/
natural or synthetic material that is intended to interact with biological systems
In contact with body fluids continuously
What do biomaterials control?
Cell fate decisions & use in regenrative therapeutics
What is matrigel?
Murine-derived heterogenous complex of ECM proteins produced by Engelbreth-Holm-Swarm sarcoma cells
What ECM proteins are in a matrigel.
Laminin
Collagen IV
Entactin
Perlecan
What are 4 limitations of matrigel?
Undefined
50% batch-to-batch variability
Variable stiffness
Limit therapeutic progression
What is stiffness measured in/
Gā elastic modulus - materials resistance to being deformed
What is PEG?
Polyethylene glycol - synthetic polymer
Does PEG support stem cell expansion?
No PEG is inert
What would stiff environment hinder?
growth & morphogenesis
What was the dynamic hydrogel composed of?
Combined stable PEG with hydrolytically degradable PED polymer with RGD & Laminin incorporation
What does the dynamic hydrogel do to stiffness?
Initial high stiffness for stem cell maintenance & lower stiffness for cellular differentiation
What proteins were decreased in stiffer gel in kidney type organoids?
WT1, LTL, VEGFR
Does stiffness have a cell type specific effect?
yes - podocytes favour stiffer ECM
What does growth induced compression impact?
Size of cerebral organoids
What are neural rosettes/
Lumenized neuroepithelium during embryonic brain development
What do kidneys organoids in SAPH reduce?
Off-target cells in comparison to Transwell
Which environment were the Kidney cells better organised?
Stiffer environment
