Electrospun nanostructured scaffolds

Electrospun nanostructured scaffolds have been intensively investigated as 3-D scaffolds for bone engineering. The principle of electrospinning is to apply high voltage on polymer solution or melt to overcome its surface tension and draw the... 

Figure 73 Representative 3-D nanostructured scaffolds for bone-specific drug delivery systems, (a) Electrospun sitk scaffold with BMP-2 loaded, scale bar=5 pm (reprinted from Ref. [86] with permission) (b) Self-assembled peptide-amphiphile (PA) nanofibers network, scale bar= 1 mi (reprinted from Ref. [87] with permission) (c) Nanocrystalline apatite modified poly(lactide-co-glycolide) (PLAGA) microsphere scaffolds, scale bar=2pm (reprinted from Ref. [88] with permission) and (d) poly(L-lactic acid) (PLLA) nanofibrous scaffolds incorporated with poly(lactic-co-glycolic acid) (PLGA) nanospheres, scale bar=2 pm (reprinted from Ref. [89] with permission).

The ultimate tensile test results showed that the samples electrospun with a negative polarity voltage broke at one half the strain, 28% vs. 60%, and only achieved a UTS of 0.23 MPa, one half the positive polarity s 0.51 MPa. While the total porosity of the samples was insignificantly different (74.5% 1.3% positive and 77.4% 1.8% negative), the distribution of pore sizes determined by mercury porosimetry was less uniform for positive samples, with a strong peak at a pore diameter of 5 pm. SEM pictures seemed to show that at the nanostructure level the fibers branched differently. These properties of the fabric were significantly different in ways that may affect its use as a tissue engineering scaffold. 

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