Electrohydrodynamic Co-Jetting: A Design Platform for Multifunctional Structures for Drug Delivery and Tissue Engineering Applications

Electrohydrodynamic co-jetting of two or more poly (lactide-co-glycolide) polymer solutions was employed to fabricate degradable microparticles and microfibers comprised of several distinguishable compartments.[1-3] As a proof of versatility of this approach, particles and fibers with two to seven individual compartments were made.[1,3] In case of particles, high volatilities of organic solvents led to solvent evaporation before thermodynamic equilibrium could be achieved, yielding bicompartmental non-spherical shapes. This was demonstrated by fabrication of discoid, rod-like, and hemiporous microparticles. In case of fibers, optimization of different electrospinning solution and process parameters such as viscosity, flow rate, etc., temporal and spatial perturbations observed during conventional electrospinning could be minimized to yield highly monodisperse and aligned fiber bundles, the orientation, size, and arrangement of which could be controlled in a highly predictable fashion. These unique fibers were then utilized to produce cylindrical microparticles via cryotoming. Uniform, multicompartmental biodegradable microcylinders with controllable number, size, aspect ratio and orientation of compartments were thus fabricated.[2] By introduction of ‘sacrificial' compartments, control over shape of microcylinders was also demonstrated. Organic-Inorganic hybrid materials were also created by encapsulation of magnetite nanocrystals selectively in one compartment only. Thus, design of versatile microstructures with precisely tunable number of compartments, and possessing a variety of shapes and sizes was demonstrated via electrohydrodynamic co-jetting. These materials may serve as the next generation of smart structures for drug delivery, drug targeting, and diagnostic applications.

References:

1. Bhaskar, S., Lahann, J., J. Am. Chem. Soc. 2009, in press.

2. Bhaskar, S., Hitt, J., Chang, S. L., Lahann, J., Angew Chem. Int. Ed. 2009, in press.

3. Bhaskar, S., Roh, K. H., Jiang, X., Baker, G. L., Lahann, J., Macromol. Rapid Commun. 2008, 29, 20, 1655.