Page 312 - Biodegradable Polyesters

290 11 Electrospun Biopolymer Nanofibers and Their Composites for Drug Delivery Applications

successfully entrapped in electrosprayed alginate hydrogel beads. The hydrogel
matrix-entrapped PLGA-paclitaxel microspheres exhibited a sustained drug
release over 60 days at near-zero-order kinetics with a low initial burst release.
Preserved cytotoxicity of paclitaxel against C6 glioma was further confirmed
by cell-culture studies, indicating that electrosprayed paclitaxel-loaded particles
were more successful in subcutaneous tumor-volume reduction compared to
Taxol and the control sample [81].
Cancer therapy is a great challenge in the world of medical science as a
considerable number of deaths occur because of the ineffectiveness of current
therapeutic strategies to treat cancer. Therefore, a wide range of cancer therapeu-
tic agents and techniques have been developed to effectively treat various cancers
via mechanisms such as metabolism revision, interaction with microtubule
degradation to improve mitotic arrest, reduction of cell motility, and interruption
to intercellular signal transmission. Gulfam et al. used the electrospray deposition
system to synthesize gliadin and gliadin–gelatin composite nanoparticles for
delivery and controlled release of an anticancer drug (e.g., cyclophosphamide).
Cyclophosphamide was gradually released from gliadin nanoparticles for 48 h,
while gliadin–gelatin composite nanoparticles released cyclophosphamide in a
rapid manner. Furthermore, breast cancer cells cultured with cyclophosphamide-
loaded 7% gliadin nanoparticles for 24 h were demonstrated to become apoptotic,
confirmed by Western blotting analysis, making gliadin-based nanoparticles a
powerful tool for delivery and controlled release of anticancer drugs [82]. Coaxial
tricapillary electrospray was also used to produce multishell particles of PLGA-
doxorubicin/PDLLA-paclitaxel/PLGA. By altering polymer concentrations, flow
rate, particle size, and shell thickness, both paclitaxel and doxorubicin show low
initial burst release rates with stable and zero-order profiles as drug delivery
systems for cancer therapy [83].
Even though electrospraying is a known process for particle fabrication, it
was also introduced as an innovative method for film production instead of
the common solution-casting method. Electrospraying-deposited films can be
applied for local tumor chemotherapy or single-/multilayered coating of stents
with drug-encapsulated polymers [84]. Biodegradable films with controllable
thickness were developed for sustained release applications using the electrospray
deposition technique. The model anticancer drug paclitaxel is in an amorphous
form in PLGA matrix even for up to 30% drug loading. In vitro release profile
indicates that sustained release of paclitaxel from the films takes place for more
than 85 days, without the tri-phasic release profile that is typical for PLGA films.
The phase contrast images clearly suggest a slight decrease in the number of C6
glioma cells as the paclitaxel loading within the polymeric films is increased.
Along with active particulate drug delivery systems, smart multifunctional
micro/nanoparticles based on polymeric or inorganic materials are receiving
much interest owing to their ability to target/image a specific tissue, followed
by stimulated drug release via an external cue, such as ultrasound, pH, temper-
ature, or magnetic fields [85–87]. Wu et al. [88] reported a novel application
of electrospray to construct bioresponsive peptide-based particulates from