Cardiac Tissue Engineering Flashcards
(21 cards)
What is the main goal of cardiac tissue engineering?
To restore or replace damaged heart tissue after myocardial infarction using engineered constructs.
Why is scar tissue problematic in the heart?
It is stiff and non-contractile, reducing heart efficiency and potentially leading to heart failure.
Which cell types are commonly used in cardiac patches and why?
Cardiomyocytes: Heart cells
Endothelial cells: Vascularisation
Fibroblasts: Form and maintain ECM
Give 2 examples of natural polymers used in cardiac tissue engineering
PHAs and alginate
What does the monomer chain length of PHAs affect?
It affects the mechanical properties: short = brittle, medium = elastomeric
What property of alginate makes it useful in cardiac patches?
It degrades quickly and can encapsulate cells for faster delivery.
What functional groups allow PHAs to be processed into polyesters?
Hydroxyl (-OH) and carboxylic acid groups, enabling condensation polymerisation.
Why is anisotropy important in cardiac tissue engineering?
To mimic the aligned structure of native cardiomyocytes for proper contraction.
What is the main difference between electrospinning and melt electrowriting?
Electrospinning creates random fibres; MEW creates highly ordered, CAD-controlled fibre structures.
Why must scaffold pore size be controlled?
To support cell adhesion, allow nutrient diffusion and vascularisation
How does MEW work?
A polymer melt is loaded into the spinneret, and an electrical field is applied to control the deposition of the charged jet onto the collector
How does gyrospinning work?
A centrifugal force propels polymer outwards and the fibres stretch due to an applied electrostatic force. The fibres are collected on a rotating drum, forming a non-woven mat of aligned fibres.
What growth factor is commonly used to promote vascularisation in cardiac patches?
VEGF-A
What type of emulsion is used for delivering hydrophilic drugs?
Water-in-oil-in-water (W/O/W) emulsion
Why is controlled drug release important in cardiac tissue engineering?
To localise treatment effects and minimise systemic side effects.
What in vitro test confirms functional cardiomyocyte contraction?
Measurement of calcium transients and beat kinetics.
How can endothelial cell presence on scaffolds be verified?
Using markers like CD31 and dyes like Hoechst and FSP1
What result suggests good integration of a cardiac patch in vivo?
No fibrous encapsulation and evidence of vascularisation
List the design requirements of a cardiac patch
Anisotropic structure
Mechanical matching (e.g. stiffness)
Electrical conductivity
Vascularisation
Porosity
Biocompatible
Biodegradable
Explain why PLGA may or may not be a suitable biomaterial
Biocompatible (FDA approved)
Non-toxic byproducts
Can be MEW or 3D printed
Can incorporate VEGF, IGF-1 etc
Suitable mechanical properties
Surface modification can encourage cell adhesion
Already used in vascular grafts
