Biomedical Engineering Reference
In-Depth Information
diameter of 91.2 ± 5.2 nm with OZ entrapment efficiency of 68.91 ± 2.31%.
The in vitro studies showed a biphasic drug release pattern with an initial burst
release followed by sustained release (43.26 ± 0.156% after 120 h) with a Fick's
diffusion-based release mechanism.
152
The ex vivo diffusion using sheep nasal
mucosa showed 13.21 ± 1.59% drug diffusion from the PLGA in 210 min. Study
of sheep nasal mucosa showed no significant adverse effect of the OZ-loaded
PLGA. The in vivo pharmacokinetic studies showed 6.35 and 10.86 times
higher uptake of intranasal (i.n.) OZ delivery with PLGA than in solution that
is delivered through i.v. and i.n. route, respectively. These results hold promise
for OZ delivery directly to the brain after i.n. delivery in the presence of PLGA.
PLGA-enhanced delivery to the brain can increase drug concentration in the
brain for improving the treatment of central nervous system (CNS) disorders.
152
Nano-enabled formulations have also been evaluated as ocular drug delivery
vehicles to enhance the absorption of therapeutic drugs, improve bioavailability,
reduce systemic side effects, and sustain intraocular levels of drugs.
151
Just as
in the delivery of drugs to other tissues, polymeric NMs offer unique features
while preserving the ease of drug delivery in liquid form, and to improve the
corneal and conjunctival penetration of therapeutic drugs and peptides, they
sustain drug levels while also reducing systemic side effects.
155
Of the known
polymeric NMs, PLGA is ideal for ocular therapy due to its biocompatibility,
safety, regulatory approval, and wide use.
54,59,150,152,153,156,157,158,159
Jain et al.
151
designed and evaluated the use of PLGA-CS complex for ocular drug delivery.
Fluorescent Rhodamine (Rd) PLGA-CS complexes were prepared by iono-
tropic gelation method and tested on rabbit cornea for retention, uptake, and
penetration. They reported that both ex vivo and in vivo studies showed greater
amounts of NMs delivered Rd in the cornea than those delivered only from solu-
tion.
151
Confocal microscopy of the corneas revealed paracellular and transcel-
lular uptake supporting possible adsorptive-mediated endocytosis and opening
of the TJs between epithelial cells.
Wang et al.
153
reported the use of combination of two or more therapeu-
tic drugs to minimize the limitation of single-drug chemotherapy in antitumor
treatment that includes development of drug resistance, high toxicity, and regi-
men to minimize the amount of each drug achieve the synergistic effect for
cancer therapies. Other NMs had been used to deliver combination chemothera-
peutic drugs using drug carriers, such as micelles, liposomes, and inorganic
NPs.
153
In this paper, Wang and coworkers emulsified an amphiphilic copoly-
mer methoxy poly(ethylene glycol)-poly(lactide-co-glycolide) (mPEG-PLGA)
that were easy to produce, biocompatible, and exhibited high loading efficacy.
These NPs were sued to codeliver hydrophilic dox and hydrophobic TAX.
The drug release and cellular uptake of the codelivery platform showed that
both drugs were effectively taken up by the cells and exhibited suppression
of tumor cell growth more efficiently than the delivery of either dox or TAX
at the same concentrations. This indicated that codelivery with the NMs had
a synergistic effect.
153
In this study, the NMs' drug loading with a dox/TAX at
