Microfluidic Synthesis of Multi-layer Nanoparticles for Drug & Gene Delivery

Multiple layer nanoparticles offers a likelihood of success in drug delivery, as it provides a solution for a more controllable drug release, as with such structures, control over the capsule wall thickness, permeability, stability, and degradation characteristics can be achieved (Kumar, 2008). Using PDMS microfluidic devices to synthesize polymeric multilayer microparticles has become popular recently. The generation of complex emulsions, such as double and triple emulsions, is also achievable with such devices (Roney et al., 2005). However, limitations with these devices are: the microchannel surface property is crucial to maintain the desired flow within the microdevice; droplets which form within the microchannels require a cross-linking agent to be solidified into particles; the size of the droplets is limited to the size of microchannels, usually around 50-100 mm, which is too large to be used for drug delivery; and the amount of droplets or particles produced is limited as the droplets/particles are formed one by one. Therefore, in this study, we present a novel technique on fast multilayer polymeric nanoparticles synthesis via surface acoustic wave (SAW) atomization using a microfluidic device. We are able to show (1) successful synthesis of multilayer polymeric structure, and (2) fast generation of monodispersed particles in nanosize. Compared to conventional methods, SAW atomization is fast and have less limitations in the usage of surfactant and templates. Compared to traditional ultrasonic atomization and electrospraying, SAW atomization driven at much higher frequency is more suitable for shear and heat sensitive drug delivery.