Scaffold Design Flashcards
what are the functions of scaffolds?
- provide a temporary support structure for the tissue they are intended to replace
- create a substrate for cells to attach grow, proliferate migrate and differentiate on
- serve as a delivery vehicle for cells
- enable the efficient transport of nutrients, growth factors, blood vessels and removal of waste materials
Which are the characteristics required of the scaffold?
a. porosity
b. permeability
c. pore interconnectivity
d. all of above
All of above
Why shouldn’t the rate of degradation of scaffolds be to high or too low?
rate of degration must match the rate of regrowth of new tissue.
- if it is too high, newly formed tissue will be exposed to higher forces than it can tolerate, thus it can fail
- if degradation is to slow, the scaffold may shield from stresses that the growing tissue should experience, in order to adequately strengthen that tissue. if the tissue isn’t strengthen appropriately, it may be more susceptible for injury later on.
The two necessary characteristics of scaffolds are that they must be ___________- and ________________.
biocompatible- not produce an unfavorable physiological response
biodegradable- get broken down eventually and be eliminated from the body via naturally occcuring processes.
It is important that scaffolds have the same ___ properties as the tissue they are replacing, due to the fact that they will provide temporary support and bear any loads that the tissue experiences
mechanical properities
Give two functions of a scaffold
Providing a temporary support structure for the tissue that they are intended to replace
- Creating a substrate for cells to attach grow, proliferate migrate and differentiate on.
- Serving as a delivery vehicle for cells, facilitating their retention and distribution in the region where new tissue growth is desired.
- Enabling the efficient transport of nutrients, growth factors, blood vessels and removal of waste materials
why must the pores of a scaffold be interconnected?
to help with delivery of nutrients to the interior and removal of waste to exterior of scaffolds, these also ties into transport proteins, cell migration, and tissue ingrowth
True/false: a scaffold can be completely solid?
FALSE….. cells need to grow and to do this they need to be supplied with nutrients
Define pearmeablility
is the measure of ease with which a fluid can flow through a structure
State and elaborate on two basic requirements of a scaffold
Be biocompatible i.e not produce an unfavorable physiological response
- Be biodegradable i.e get broken down eventually and be eliminated from the body via naturally occurring processes
- Have desired surface properties to enable cell attachment, growth proliferation and differentiation as well as extracellular matrix formation
- Have optimum architectural properties in terms of pore size, porosity, pore interconnectivity and permeability and to allow for efficient delivery of nutrients, growth factors, blood vessels and removal of waste.
What is porosity, and why is it important?
it is the amount of void space within the scaffold structure,
It helps promote uniform cell delivery and ingrowth as well as having a network for optimal diffusion of nutrients and waste
Give the definition and difference between biocompatible and biodegradable
- Be biocompatible i.e not produce an unfavorable physiological response
- Be biodegradable i.e get broken down eventually and be eliminated from the body via naturally occurring processes
Is porosity important in scafffolding? why or why not?
yes, it allows for uniform cell delivery and in growth as well as have an open pore network for optimal diffusion of nutrients and waste
state two techniques used for pore characterization?
Accessible pore volume- can be characterized through the measurement of flow rate of fluid flow through interconncting pores.
micro-computed tomography- used to generate computer models for porous materials and for analyzing scaffold architecture
