Fabrication of Biodegradable Microcapsules Utilizing 3D, Surface Modified PDMS Microfluidic Devices

We have successfully demonstrated the fabrication of biodegradable and magnetic microcapsules utilizing PDMS double emulsification devices. Specially designed 3D microfluidic channels with surface modified by a self-aligned photo-grafting process are employed to shape immiscible fluids into monodisperse W/O/W emulsions. By varying the outer and inner fluid flow-rates, the overall and core sizes of the resulting double emulsions can be adjusted accordingly. Biodegradable materials and surface-treated gamma-Fe₂O₃ nanoparticles are dispersed uniformly in the middle organic phase, and solidified into magnetic microcapsules once the solvent is extracted. In the prototype demonstration, microcapsules made up of poly(L-lactic acid), trilaurin and phosphocholine (DOPC) are successfully fabricated. As such, the proposed PDMS micro-devices could potentially serve as versatile encapsulation tools, which are desired for a variety of biological and pharmaceutical applications.