The primary goals of the fabrication and operation of artificial organelles are to create reaction vessels for the construction of biologically significant products and to employ such a platform to gain a fundamental understanding of organelle structure and function. Digital microfluidics facilitates open droplet movement across a 2D grid-like surface by the process of electrowetting. This technology has opened up new opportunities to design nanoscale biomimetic droplet vesicle-based reaction systems. These systems can be used to mimic the natural fluid vesicles that operate in organelles. Using digital microfluidics, recombinant enzyme technology, and magnetic nanoparticles, we have created a functional prototype of an artificial Endoplasmic reticulum and the Golgi organelles. These artificial organelles allow for in vitro protein core biosynthesis followed by enzymatically modification of glycosaminoglycans analogous to biosynthesis in eukaryotic cells.
Figure. An artificial Golgi and artificial ER are inspired from their natural counterparts. (a) A cartoon depicting the Golgi and ER of a eukaryotic cell. Proteins are synthesized in the ER, and then sent to the Golgi for posttranslational modification resulting in glycoprotein and PG products. (b) The design of an artificial Golgi/ER digital microfluidic chip for the biosynthesis of the HS-PG is shown. HS-PG core protein is first synthesized on a magnetic nanoparticle in the artificial ER by in vitro translation. The particle holding core protein is then transferred into the artificial Golgi portion of the digital microfluidic chip where it is glycosylated to yield HS-PG. The large boxes (multicolor) are reagents and enzyme reservoir electrodes, and the small boxes (light green) are electrodes for droplet movement, mixing, and sequestration. (c) A cartoon depicting the process of in vitro translation and glycosylation in the artificial ER/Golgi device.
