Abstract
Purpose: :
To investigate an alternative microfabrication technique to enhance the drug encapsulation efficiency and reduce the antibody damage for long-term sustained release of anti-VEGF drug loaded microparticles in age-related macular degeneration.
Methods: :
The co-axial electrohydrodynamic atomization process was used to overcome the limitations of the traditional double emulsion method for microfabrication of multifunctional drug-loaded microparticles. The process setup included a co-axial needle, a ground plate, a droplet collector, and an inline video camera. The inner and outer channels of the co-axial needle were connected to two syringe pumps and infused with a phosphate buffered saline (PBS) solution of the anti-VEGF drugs, and an organic solution of poly (lactic-co-glycolic acid) (PLGA), respectively. Various fluorescent dyes, such as Nile Red, were added to the PLGA solution to visualize the shell structure. Different drugs, such as Lucentis, were encapsulated. A total voltage of 14kV was applied between the co-axial needle and the ground plate so that a stable cone-jet was formed at the co-axial needle, broken into droplets, and collected by the droplet collector filled with distilled water. The core-shell ratio of the fabricated microparticles was controlled by adjusting several process parameters, such as the ratio of the inner and outer flow rates, the concentration of PLGA, and the applied voltage.
Results: :
With the co-axial electrohydrodynamic atomization process, we were able to fabricate drug-loaded microparticles with the size ranging from 1 to 5um. The morphology of these microparticles was characterized by scanning electron microscopy, and the cone-shell structure was confirmed by confocal microscopy.
Conclusions: :
The co-axial electrohydrodynamic atomization process was successful in producing drug-loaded mircoparticles. Future studies will investigate protection of anti-VEGF drugs from process-induced damage with a high encapsulation efficiency. The core-shell ratio can be easily controlled for programmed long-term drug release.
Keywords: age-related macular degeneration • retina • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)