posted on 2021-01-23, 02:27authored byXingyu He, Zheng Yuan, Samantha Gaeke, Winston W.-Y. Kao, S. Kevin Li, Daniel Miller, Basil Williams, Yoonjee C. Park
To
treat chronic posterior eye diseases, frequent intravitreal
injections or sustained-release drug implants are the current standard
of care. Sustained-release drug implants often involve burst release
of the drugs and the dosage from the implants cannot be controlled
after implantation, which may lead to local side effects. The present
study attempts to develop a dosage-controllable drug delivery implant
that consists of a nanoporous biodegradable PLGA capsule and light-activated
liposomes. Controllable drug release from the implant was achieved
using a pulsed near-infrared (NIR) laser both in vitro and in vivo.
The in vitro drug release kinetics from two different initial dose
implants, 1000 and 500 μg, was analyzed by fitting zero-order
and first-order kinetics, as well as the Korsmeyer–Peppas and
Higuchi models. The 1000 and 500 μg implants fit the first-order
and zero-order kinetics model, respectively, the best. The multiple
drug releases in the vitreous were determined by an in vivo fluorimeter,
which was consistent with the in vitro data. The dose released was
also clinically relevant. Histology and optical and ultrasound imaging
data showed no abnormality in the eyes received implant treatment,
suggesting that the drug delivery system was safe to the retina. This
on-demand dose-controllable drug delivery system could be potentially
used for long-term posterior eye disease treatment to avoid frequent
invasive injections.