Near-infrared photothermal activation of microgels incorporating polypyrrole nanotransducers through droplet microfluidics

Light responsive microgels which can be controlled remotely have wide applications in advanced drug delivery, biosensing, micro-actuator, microfluidic control and micropump. In this study, Poly (N-isopropylacrylamide) (pNIPAM) microgels incorporating polypyrrole nanoparticles as organic photothermal transducers through droplet microfluidics were demonstrated. These microgels have near-infrared light responsive ability. Site-specific control of de-swelling/swelling for these composite microgels is achieved remotely with NIR laser on/off cycles. Due to its least absorption by biological molecules and ability to penetrate tissue without tissue damage, in vivo applications of these composite microgels as remotely-controlled pulsed drug release carriers and in vivo control of the implanted microfluidic devices can be conveniently achieved.