Biomedical Engineering Reference
In-Depth Information
TABLE 4.1
Natural and Synthetic Biodegradable Polymers Used
in Electrospinning Scaffold Tissue Engineering
Naturally Derived
Synthetic
Collagen
Poly(lactic acid)
Gelatin
Poly(glycolic acid)
Chitosan
Poly(lactic-co-glycolic acid)
Chitin
Poly(ε-caprolactone)
Cellulose
Poly(lactide-co-caprolactone)
Elastin
Poly(vinyl alcohol)
Starch
Silk fibroin
Fibrinogen
Hyaluronan
TABLE 4.2
Physical Properties of Some Polymers Used for Electrospinning of Tissue
Engineering Constructs
Fiber Diameter
(nm)
Stress
(MPa)
Tensile Modulus
(MPa)
Material
Collagen type I
56
250
-
-
Collagen type I 1:50 polyethyleneoxide
57
100-150
037
12
Gelatin
58
200
5.77
499
Poly(lactide-co-glycolic acid) (85:15)
59
500-800
22.67
323.15
Poly(lactide-co-glycolic acid) (75:25)
60
550
4.67
110.78
Poly(ε-caprolactone)
61
200-600
-
-
Poly(lactide-co-ε-caprolactone)
62
470
6.3
44
morphology, of the fibers are the nozzle size, surface tension, quality of the
solvent, diffusion coefficient, flow rate, and temperature. Some of these prop-
erties may be altered by the addition of salt or surfactant.
48
In Table 4.2, an
overview is given of the physical properties of some frequently used poly-
mers for electrospinning.
4.2.2 Modification of Nanofibrous Scaffolds
Considering the everlasting demand for further innovation of scaffold mate-
rials, there is a possibility to improve nanofibrous scaffolds to a greater extent
by several modifications. For instance, mechanical strength and stability of
the scaffolds can be improved by cross-linking the polymers, and biocom-
patibility of the construct might be improved by introducing proteins and
ligands into the scaffold. As an example, addition of poly(ε-CBZ-l-lysine)
to PLLA scaffolds resulted in increased binding of collagen type II, which
