Biomedical Engineering Reference
In-Depth Information
Nanoparticles for Drug and Gene Delivery in Treating
Diseases of the Eye
Shreya S. Kulkarni and Uday B. Kompella
Abstract
Using biodegradable polymeric nanoparticles as model systems for drug and gene delivery, this chapter
describes commonly used methods for preparing and characterizing nanoparticles. This chapter focuses on
emulsion solvent evaporation-based methods for encapsulating hydrophilic as well as lipophilic drugs in
polymeric nanoparticles. In order to describe methods for preparing nanoparticles, we have chosen poly
(lactide) (PLA)/poly(lactide-co-glycolide) (PLGA) as the carrier materials for nanoparticles intended
for drug and gene delivery. Nanoparticles intended for drug and gene delivery can be characterized for
various parameters including particle size, size distribution, morphology, zeta potential, drug loading,
syringeability and injectability, in vitro drug release, and stability. Methods for the measurement of these
parameters, which influence the performance characteristics of nanoparticles in vivo, are also discussed in
this chapter.
Key words
Nanoparticles, Manufacturing, Drug delivery, Gene delivery, Emulsion solvent
evaporation, Particle size, Zeta potential, Drug loading, Drug release, Stability
1
Introduction
Currently, the incidence of diseases of the anterior as well as
posterior segments of the eye is on the rise [
1
]. Some of the
common anterior eye diseases are cataract, glaucoma, and uveitis
while some of the posterior eye diseases are diabetic retinopathy,
retinal degenerations including age-related macular degeneration
(AMD) and retinitis pigmentosa. Although not life threatening,
these conditions negatively affect the quality of life by causing
ocular discomfort, blurring of vision and ultimately complete
blindness [
2
]. To treat these diseases, several therapeutic agents
including conventional small molecule drugs as well as macromo-
lecules including proteins and nucleic acid therapies are under
development. While treating ocular pathologies, efficient delivery
of therapeutic agent to the target tissues is a critical parameter in
developing safe and effective drug candidates. Both anterior and
posterior segment diseases are lifelong diseases and therefore, sus-
tained drug levels at the target site are desirable. Indeed, sustained
drug delivery systems are known to maintain therapeutic drug
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