Copyright 2016 Biomedical Microdevices Laboratory
 O Khandan, A Famili, MY Kahook, and MP Rao. IEEE EMBC 2012.
Research in this thrust focuses on addressing a
critical unmet need, namely the development of a
safe, simple, and efficacious means for delivering
drugs to the eye. We have recently reported
Ti-based microneedle (MN) devices that represent
our first step towards achieving this goal .
MNs offer promise due to their diminutive size,
which allows penetration into, but not through
sclera or cornea. This provides a minimally-
invasive means for precisely depositing drugs
within such tissues, thus enabling circumvention
of intrinsic transport barriers and clearance
mechanisms, while also minimizing potential for
retinal damage. Although both passive and active
MNs have been reported, the former may prove
more advantageous for eventual clinical use, due
to their lower complexity and cost. However,
potential for translation will be constrained by the
limited carrying capacity of devices demonstrated
to date, since this necessitates use of excessively
large MN arrays to deliver required dosages.
The fenestrated Ti MNs shown here seek to
address this limitation. Thus far, we have
demonstrated that these devices: a) increase
carrying capacity up to 5-fold relative to
comparable solid MNs; b) provide potential for
enhanced safety, due to their graceful,
plasticity-based failure mode; and c) possess
sufficient stiffness for corneal insertion.
MY Kahook, Ophthalmology, University of Colorado
School of Medicine
Top: Scanning electron micrograph of
fenestrated Ti microneedle and
conventional 26g stainless steel
hypodermic needle. Bottom: Histological
section of excised rabbit cornea at
insertion site of fenestrated Ti
microneedle (H&E stain) .
UCR Regents Faculty Fellowship (PI: Rao)