Preparation of multilayered polymeric structures using a novel four-needle coaxial electrohydrodynamic device

Abstract

Coaxial four-needle electrohydrodynamic forming is applied for the first time to prepare layered structures in both particle and fiber form. Four different biocompatible polymers, polyethylene glycol, poly (lactic-co-glycolic acid), polycaprolactone, and polymethylsilsesquioxane, are used to generate four distinct layers confirmed using transmission and scanning electron microscopy combined with focused ion beam milling. The incorporation and release of different dyes within the polymeric system of four layers are demonstrated, something that is much desired in modern applications such as the polypill where multiple active pharmaceutical ingredients can be combined to treat numerous diseases.

Keywords: coaxial device; electrohydrodynamic; multilayered structures; polymers.

Figure 1

Schematic illustration of a) the experimental set-up of the EHD process using a four-needle device for forming of four-layer structures with a stable jet (inset) and b) the coaxial needle arrangement with labeled dimensions, where ID and OD are internal and outer diameters, respectively.

Figure 2

a–c) SEM–FIB microscopic images of four-layered fibers. a) Fibers at low magnification, b) surface morphology of the outer layer, and c) FIB sectioning showing the cross-section of the fibers with four distinct layers, labeled accordingly.

Figure 3

a) SEM image of four-layered particles at low magnification b) Bright-field TEM image of a particle showing four distinct layers. c) Release profile for four layered particle consisting of PEG, PLGA, PCL, and PMSQ loaded with Evans blue, pyronin B, pinacyanol chloride, and hematoxylin, respectively.