Fabrication of biodegradable poly(lactic acid) particles in flow focusing glass capillary devices

Fabrication of biodegradable poly(lactic acid) particles in flow focusing glass capillary device

Fabrication of monodisperse poly(dl- lactic acid) microparticles using drop microfluidics

Monodisperse poly(dl-lactic acid) particles with a diameter between 11 and 121 μm were fabricated by drop microfluidics/solvent evaporation method using flow focusing glass capillary device. In the dripping regime, the ratio of droplet diameter to orifice diameter was in the range of 0.37−1.34 and was inversely proportional to the 0.39 power of the ratio of the continuous phase flow rate to dispersed phase flow rate

Emulsion templating of poly(lactic acid) particles: droplet formation behavior

Monodisperse poly(dl-lactic acid) (PLA) particles of diameters between 11 and 121 ?m were fabricated in flow focusing glass microcapillary devices by evaporation of dichloromethane (DCM) from emulsion droplets at room temperature. The dispersed phase was 5% (w/w) PLA in DCM containing 0.1−2 mM Nile red and the continuous phase was 5% (w/w) poly(vinyl alcohol) in reverse osmosis water. Particle diameter was 2.7 times smaller than the diameter of the emulsion droplet template indicating very low particle porosity. Monodisperse droplets have only been produced under dripping regime using a wide range of dispersed phase flow rates (0.002−7.2 cm3h-1), continuous phase flow rates (0.3−30 cm3h-1) and orifice diameters (50−237 ?m). In the dripping regime, the ratio of droplet diameter to orifice diameter was inversely proportional to the 0.39 power of the ratio of the continuous phase flow rate to dispersed phase flow rate. Highly uniform droplets with a coefficient of variation (CV) below 2 % and a ratio of the droplet diameter to orifice diameter of 0.5−1 were obtained at flow rate ratios of 4−25. Under jetting regime, polydisperse droplets (CV > 6 %) were formed by detachment from relatively long jets (between 4 and 10 times longer than droplet diameter) and a ratio of the droplet size to orifice size was 2−5

Fabrication of biodegradable poly(lactic acid) particles in flow-focusing glass capillary devices

Monodisperse poly(dl-lactic acid) (PLA) particles with a diameter in the range from 12 to 100 9m were fabricated in flow focusing glass capillary devices by evaporation of dichloromethane (DCM) from emulsions at room temperature. The dispersed phase was 5% (w/w) PLA in DCM containing a small amount of Nile red and the continuous phase was 5% (w/w) poly(vinyl alcohol) in reverse osmosis water. Particle diameter was 2.7 times smaller than the size of the emulsion droplet template indicating that the particle porosity was very low. SEM images revealed that the majority of particle pores are in the sub-micron region but in some instances these pores can reach 3 9m in diameter. Droplet diameter was influenced by the flow rates of the two phases and the entry diameter of the collection capillary tube; droplet diameters decreased with increasing values of the flow rate ratio of the dispersed to continuous phase to reach constant minimum values at 40-60 % orifice diameter. At flow rate ratios less than 5, jetting can occur, giving rise to large droplets formed by detachment from relatively long jets (~10 times longer than droplet diameter)

Emulsion Templating of Poly(lactic acid) Particles: Droplet Formation Behavior

Monodisperse poly(DL-lactic acid) (PLA) particles of diameters between 11 and 121 mu m were fabricated in flow focusing glass microcapillary devices by evaporation of dichloromethane (DCM) from emulsion droplets at room temperature. The dispersed phase was 5% (w/w) PLA in DCM containing 0.1-2 mM Nile Red and the continuous phase was 5% (w/w) poly(vinyl alcohol) in reverse osmosis water. Particle diameter was 2.7 times smaller than the diameter of the emulsion droplet template, indicating very low particle porosity. Monodisperse droplets have only been produced under dripping regime using a wide range of dispersed phase flow rates (0.002-7.2 cm(3).h(-1)), continuous phase flow rates (0.3-30 cm(3).h(-1)), and orifice diameters (50-237 mu m). In the dripping regime, the ratio of droplet diameter to orifice diameter was inversely proportional to the 0.39 power of the ratio of the continuous phase flow rate to dispersed phase flow rate. Highly uniform droplets with a coefficient of variation (CV) below 2% and a ratio of the droplet diameter to orifice diameter of 0.5-1 were obtained at flow rate ratios of 4-25. Under jetting regime, polydisperse droplets (CV GT 6%) were formed by detachment from relatively long jets (between 4 and 10 times longer than droplet diameter) and a ratio of the droplet size to orifice size of 2-5

Perfluoroalkyl-Functionalized Hyperbranched Polyglycerol as Pore Forming Agents and Supramolecular Hosts in Polymer Microspheres

Perfluoroalkyl-functionalized, hyperbranched polyglycerols that produce stable microbubbles are integrated into a microfluidic emulsion to create porous microspheres. In a previously-presented work a dendrimer with a perfluorinated shell was used. By replacing this dendrimer core with a hyperbranched core and evaluating different core sizes and degrees of fluorinated shell functionalization, we optimized the process to a more convenient synthesis and higher porosities. The new hyperbranched polyglycerol porogens produced more pores and can be used to prepare microspheres with porosity up to 12% (v/v). The presented preparation forms pores with a perfluoroalkyl-functionalized surface that enables the resulting microspheres to act as supramolecular host systems. The microspheres can incorporate gases into the pores and actives in the polymer matrix, while the perfluoroalkylated pore surface can be used to immobilize perfluoro-tagged molecules onto the pores by fluorous-fluorous interaction