(a) Discuss the importance of porosity and pore size in tissue engineering scaffolds.
Generally, scaffold permeability increases with increasing pore size. Tissue engineering applications commonly encompass the use of three-dimensional scaffolds to provide a suitable micro environment for the incorporation of cells or growth factors to regenerate damaged tissues or organs. The different pore size and porosity measurement methods will also be discussed. Scaffolds with graded porosity have also been studied for their ability to better represent the actual in vivo situation where cells are exposed to layers of different tissues with varying properties.
(b) The cross-sectional area of a cylindrical scaffold is given by -
A = 2 r h
where, r = radius of a cylindrical scaffold = 6 x 10-3 m
h = height of a cylindrical scaffold = 10 x 10-3 m
then, we get
A = [(6.28 rad) (6 x 10-3 m) (10 x 10-3 m)]
A = 3.76 x 10-4 m2
(i) The Porosity calculation which will be given by -
= 1 - (T / M)
where, T = total scaffold density = ?
M = scaffold material characteristic density = 1.145 g/cm3
= porosity = 80% = 0.8
then, we get
(0.8) = 1 - [T / (1.145 g/cm3)]
[T / (1.145 g/cm3)] = [1 - (0.8)]
T = [(0.2) (1.145 g/cm3)]
T = 0.229 g/cm3
(ii) The permeability-pore size correlation which will be given by -
k = 3 d2 / [150 (1 - )2]
where, d = average pore diameter = 220 x 10-6 m
= porosity = 80% = 0.8
then, we get
k = [(0.8)3 (220 x 10-6 m)2] / [(150) (1 - 0.8)3]
k = [(2.47808 x 10-8 m2) / (1.2)]
k = 2.065 x 10-8 m2
A group of researchers have been trying to generate a degradable scaffold made of polycaprolactone (PCL)...
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