Publications by authors named "Jinsong Hua"

Polymeric composite microspheres consisting of a poly(D,L-lactic-co-glycolic acid) (PLGA) core surrounded by a poly(D,L-lactic acid) (PDLLA) shell layer were successfully fabricated by coaxial electrohydrodynamic atomization (CEHDA) process. Process conditions, including nozzle voltage and polymer solution flow rates, as well as solution parameters, such as polymer concentrations, were investigated to ensure the formation of composite microspheres with a doxorubicin-loaded PLGA core surrounded by a relatively drug-free PDLLA shell layer. Various microsphere formulations were fabricated and characterized in terms of their drug distribution, encapsulation efficiency and release.

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The initial motion of two-dimensional capsule in microchannel flow just after release is investigated in this paper by a numerical simulation method, which combines the finite volume method with the front tracking technique. The capsule is modeled as liquid medium enclosed by a thin membrane, for which linear elastic properties are taken into consideration. Three kinds of initial capsule shapes (circle, ellipse, and biconcave) and three initial positions (center-line, near-center, and near-wall positions) are considered in the simulations.

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The pinch-off of a gas bubble from a tiny nozzle immersed vertically in another quiescent viscous fluid due to buoyancy is numerically investigated. The dynamics of bubble growth and pinch-off are described by the full Navier-Stokes equations for both gas and liquid phases. The equations are solved with a finite-volume method based on the SIMPLE scheme, coupled with a front tracking method to locate the interface between the two phases.

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Electrohydrodynamic atomization (EHDA) has many applications such as electrospray ionization in mass spectroscopy, electrospray deposition of thin films, pharmaceutical productions, and polymeric particle fabrications for drug encapsulation. In the present study, EHDA was employed to produce biodegradable polymeric micro- and nanoparticles. The effects of processing parameters such as polymer concentration, flow rate, surfactants, organic salt, and setup configurations on the size and morphology of polymeric particles were investigated systematically.

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