Experimental study of manufacturing and characterization of a flow-focusing microchannel in order to produce thermoresponsive microparticles for on-demand smart drug delivery

In targeted drug delivery, the use of temperature-sensitive micro-drops as drug carriers has recently been considered. In this approach, the use of N-isopropylacrylamide microparticles as temperature-sensitive drug carriers can be effective in the topical treatment of chronic burn wounds and diabetes. In this study, first, a flow-focusing microchannel was fabricated by photolithography. Then N-isopropylacrylamide polymer solution was made with different percentages and used as a drop phase in the microchannel. 10% N-isopropylacrylamide solutions and silicone oil were used as intermediate and continuous phase currents, respectively, and N-isopropylacrylamide microparticles were produced by microchannel. The results of the study showed that by changing the ratio of intermittent to continuous phase flow from 0.14 to 0.84, the diameter of the produced droplets increases from 360 to 515 microns. It was also observed that if the syringe container containing the polymer fluid is kept cold, an aqueous solution containing 10% N-isopropylacrylamide, 0.3% BIS and 4% ammonium persulfate can be used as the drop phase And thus produced temperature-sensitive polymer droplets. Increasing the temperature of the produced micro-drops from 20 to 26° C led to a 50% reduction in their diameter.