Microfluidic synthesis of pH-sensitive multiamine hydrogel microparticles and release characterization of anticancer drug of doxorubicin (Dox)

In this paper, pH sensitive hydrogel microparticles (HMs) were synthesized in a microfluidic system with easy and controllable regulation of pH, and flow rate for drug delivery. The HMs originated from PEG derivative demonstrated low toxicity, which is an important characterization in pharmacy. Especially, an injectable multiamine hydrogel was synthesized by using condensation reaction process. The well-defined hydrogel droplets of water-in-oil was continuously generated in a cross microchannel. The size of the hydrogel droplets could be controlled by both the inlet flow rate and the pH of the pre-synthesized hydrogel in water. The hydrogel microparticles have been produced in a size ranging from 5 to 35 μm. By using MTT assay of in vitro cell viability, the hydrogel microparticles do not show cytotoxicity. The doxorubicin loaded in the hydrogel microparticles was released at low pH conditions. From in vitro testing of the pH effect on the release of a drug, HMs is a potential for drug delivery strategy to treat cancer. Also, hydrogel microparticles loaded with a drug can be applied to deliver it to human tissues with a low pH.