Design of Electrospayed non-spherical poly (L-lactide-coglicolide) microdevices for sustained drug delivery

Polymer chains entanglements in organic solvents can be considered key parameter in formation of non-spherical beads when electrospraying is employed. The shape of micro/nanometric drug delivery systems, plays a major role since it can affect circulation, extravasation, distribution and clearance in vivo of the devices. In this frame, we investigated the influence of polymer processing parameters for the design of polylactic-co-glycolic acid (PLGA) non-spherical microdevices (nSMDs) loaded with triamcinolone acetonide (TrA) prepared by electrospraying technique through a one-step process. In particular, we verified that the formation of non spherical MDs is related to the presence of entanglements among polymer chains to select the optimal solution to be sprayed. Meanwhile, the addition of TrA, a sparingly water soluble corticosteroid, did not substantially affect the particle morphology in terms of size, size distribution and circularity at all the tested drug loadings. Furthermore, the drug could be released for a prolonged period, with controlled and reproducible kinetics for over 3 weeks. The mathematical modeling of release profiles highlighted that release is mainly driven by degradation, at a higher extent in the case of low drug loading.