(4cp) Multicompartmental Microstructures Via Electrohydrodynamic Co-Jetting for Biomedical Applications

We herein describe the synthesis of anisotropic colloidal microstructures via electrohydrodynamic-cojetting for a variety of applications such as targeted drug release, tissue engineering, diagnostics, sensing and display materials.1-8 In its simplest form, two polymer solutions are flown through a modified side-by-side capillary system. Application of an electric field results in the formation of an electrospray, and solvent evaporation results in particle or fiber formation, and the interface between two polymer solutions is sustained during jet fragmentation and size reduction. Because of its intrinsic simplicity and generality, the electrohydrodynamic co-jetting process can be applied to a wide range of specialty and non-specialty materials. Furthermore, simple variations of different solution and process parameters, such as concentration, flow rate, applied voltage, etc. provides access to a vast repertoire of shapes and sizes of particles and fibers. Such novel particle geometries enable independent control of key parameters, such as chemical composition, surface functionalization, biological loading, shape, and size for each compartment. We demonstrate the fabrication of multicompartmental particles and fibers from biodegradable and hydrogel polymers, namely poly(lactide-co-glycolide) (PLGA) and poly(ethyleneimine) (PEI) via electrohydrodynamic co-jetting. We then demonstrate the versatility of this process by fabricating a variety of non-equilibrium biphasic shapes, such as discs, rods and cylinders, in addition to spheres. Fabrication of organic-inorganic hybrid materials is demonstrated via incorporation of magnetite nanoparticles, carbon nanotubes, and optical pigments. Spatioselective control over particles' surface is demonstrated via anisotropic introduction of functional groups in particles and fibers, and their selective surface modification via ?click chemistry?. Sacffolds fabricated out of such selectively modified fibers are employed for spatial cell guidance. The selective surface modification is also employed in interparticle assembly. Anisotropic PLGA/PEI particles are also employed in drug and gene delivery.