John Garner

mPEG-PLGA from PolySciTech utilized in optimization and fine-tuning of microfluidic nanoparticle formation techniques

Blog Post created by John Garner on May 2, 2017

Polymeric nanoparticles are widely used to improve solubility of poorly soluble medicines and blood-circulation times of rapidly cleared medicines. In this way, these are often utilized to improve the efficacy of medicines by ensuring more of the medication actually reaches the location of usage rather than be cleared out of the blood-stream. There are a wide variety of ways to make nanoparticles, most of which are based around mixing the polymer from a solvent that dissolves the polymer well in with a solvent that doesn’t dissolve it at all. This is typically done in the presence of a surfactant so that the polymer solidifies into tiny spheres. The easiest of these techniques is a simple emulsion. Anyone could do this, even in a kitchen. Simply dissolve a Styrofoam cup in a small amount of acetone (paint thinner), load a household blender with soapy water and slowly drip the polystyrene cup solution into the blender full of sudsy water while it is stirring at maximum speed. After a few minutes of stirring, pass the white slurry through a coffee filter to remove any big particles and you now have a milky-looking slurry of polystyrene nanoparticles. I do not actually suggest doing this because: 1) acetone is flammable, 2) there is no practical application for generating nanoparticles in your kitchen, 3) the next time you go to make milk-shakes, they may taste terrible, and 4) it will certainly void the warranty on your house-hold blender (just because you can, doesn’t mean you should try this at home). Nanoparticles made by this type of emulsion technique come out in a wide range of different sizes, because the processes which drive their formation are random. However, microfluidics is a newer technique in which the mixing is precisely controlled so that all the nanoparticles are generated at the same size and in a highly controlled manner. Defining exactly how the blending of the polymer solution with the non-solvent occurs is a process which requires a great deal of experimentation and fluid mechanics to elucidate the precise parameters (concentrations, mixing speeds, etc.) that allow for predetermined sizes of polymer nanoparticles to be made. Recently, Researchers at The University of Queensland (Australia) utilized mPEG-PLGA from PolySciTech ( of two different block sizes (PolyVivo AK026 (5k-55K) and AK037 (5K-20K)) to investigate microfluidic mechanisms for producing monodisperse nanoparticles with extremely well controlled sizes.  For this, they dissolved the polymers into acetonitrile and then processed them through an advanced microfluidics system to generate precisely sized nanoparticles. This research holds promise for the generation of well-controlled nanoparticles to encapsulate medicines and improve their efficacy. Read more: Baby, Thejus, Yun Liu, Anton PJ Middelberg, and Chun-Xia Zhao. "Fundamental studies on throughput capacities of hydrodynamic flow-focusing microfluidics for producing monodisperse polymer nanoparticles." Chemical Engineering Science (2017).


  “Abstract: Microfluidics enables the manipulation of liquids at the picoliter (or less) scale and proves to be superior over conventional bulk methods for mixing and reaction. The ability of microfluidic systems to rapidly mix reagents to provide homogeneous reaction environments, to vary the reaction conditions continuously, and to even allow reagent addition during the progress of a reaction, makes it attractive for nanoparticle synthesis. However, the low production rate limits its practical applications. Different approaches have been developed to achieve higher yield but most of them rely on the design of complex devices. Herein, we investigated fundamentally the throughput capacities of hydrodynamic flow-focusing microfluidics for producing poly (lactide-co-glycolide)-b-polyethylene glycol (PLGA-PEG) nanoparticles with uniform size ranging from 50-150 nm. The effects of different factors of microfluidic design, including channel width, channel depth, channel structure and flow rate ratios, on particle size, size distribution, and production throughput were studied and compared. In contrast to the widely used microfluidic device which has a production rate of 1.8 mg/h, our simple approach is capable of increasing the production rate of nanoparticles by more than two orders of magnitude up to 288 mg/h using a single simple device. This study demonstrated the potentials of using simple 2D microfluidic devices for a large scale production of polymeric nanoparticles that could eliminate the need for designing and fabricating complex microfluidic devices. Keywords: Microfluidics; 2D hydrodynamic flow focusing; PLGA-PEG NPs; mixing; nanoprecipitation. Highlights: A single hydrodynamic flow focusing (HFF) microfluidic device for production of polymeric nanoparticles at hundred milligram per hour scale. Tunable properties of the synthesized nanoparticles. Precise control over the size and size distribution of the synthesized nanoparticles. A library of polymer nanoparticles with systematically varied size.”

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