(212a) Microfluidic Characterization of Sustained Solute Release From Nano-Porous Hierarchical Assemblies

A new microfluidics based technique for the assessment of solute release from porous particle networks in a laminar flow environment will be presented. Latex supraparticles are fabricated via dry self-assembly method using droplet templates dispensed on superhydrophobic substrates.^1,2 The template droplets contain model solute (food-grade water soluble dye). The droplets containing the latex microsphere suspension and dissolved dye acquire and retain their spherical shape during the entire drying process due to high contact angle of the substrate. Hence the final assembly transform into near spherical structures with dye entrained in their pores. The dye functions as a model compound, the release rate of which is measured colorimetrically under laminar flow in microfluidic chips. The sustained release profile of dye from supraparticles matrices and dye pellet dissolution are quantified using concentration standards and compared to common diffusion/dissolution mass transfer models. The results illustrate the role of the uniformly porous supraparticle matrix for the prolonged continuous release and establish their potential for drug delivery applications.

References:

1. Rastogi, V.; García, A. A.; Marquez, M.; Velev, O. D., Anisotropic Particle Synthesis Inside Droplet Templates on Superhydrophobic Surfaces. Macromolecular Rapid Communications 2009, 31, 190-195.

2. Rastogi, V.; Melle, S.; Calderón, O. G.; García, A. A.; Marquez, M.; Velev, O. D., Synthesis of Light-Diffracting Assemblies from Microspheres and Nanoparticles in Droplets on a Superhydrophobic Surface. Advanced Materials 2008, 20, (22), 4263-4268.