Page 304 - Biodegradable Polyesters

282 11 Electrospun Biopolymer Nanofibers and Their Composites for Drug Delivery Applications

100
0 V
90 5 V
Released drug percentage (%) 70
10 V
80
15 V
60
50
40
30
20
10
0
100 200 300 400 500 600
Released time (min)

Figure 11.4 Effect of applied electric voltage on drug release of AF samples. (Reproduced
with permission from Ref. [46]; Copyright 2010 Elsevier.)
structural stability of GTP. Alamar blue assays exhibited that GTP-loaded com-
posite nanofibers possessed a significant inhibition effect to tumor cells, which
may have broad applications in cancer therapy [47].
Nanomaterials with sophisticated structures are one kind of the most popular
drug delivery vehicles owing to their sustained release properties [48]. In Qi’s
study, drug-loaded halloysite nanotubes (HNTs) with optimized encapsulation
efficiency were mixed with PLGA for electrospinning to form drug-loaded
composite nanofibrous mats. The results indicate that this double container drug
delivery system (both PLGA and HNTs are drug carriers) is beneficial to reduce
the burst release of drug. Moreover, the introduction of HNTs can significantly
improve the tensile strength of the polymer nanofibrous mats. Given the proved
biocompatibility of HNT-containing PLGA nanofibers via MTT assay of cell
viability and scanning electron microscopy observation of cell morphology,
the drug-loaded electrospun composite nanofibrous mats may find various
applications in tissue engineering and pharmaceutical sciences [49].
2+ 3+ x+ n−
With the general formulation of [M M (OH) ] (A ) ⋅mH O, layered
1−x x 2 x/n 2
double-hydroxides (LDHs) are a large class of host–guest layered inorganic
materials consisting of positively charged brucite-like layers and exchangeable
interlayer anions [50]. Given the good biocompatibility, low cytotoxicity, and
full protection for loaded drugs (to prolong drug activity and enhance stability
under heat or UV light), a series of pharmaceutically active compounds, such as
IBU, prednisone, and enalaprilat, have been intercalated into LDHs which exhibit
the feasibility of LDH-based tunable drug delivery systems [51, 52]. However,
drug-loaded LDHs are generally presented as a formulation of powders or
suspensions, which may largely limit their applications in drug-loading devices.
Therefore, electrospun IBU intercalated LDH/biopolymer nanofiber composites