Towards Designer Microparticles: Simultaneous Control of Anisotropy, Shape, and Size

Abstract

Biodegradable, compositionally anisotropic microparticles with two distinct compartments that exhibit controlled shapes and sizes are fabricated. These multifunctional particles are prepared by electrohydrodynamic co-jetting of poly(lactide-co-glycolide) polymer solutions. By varying different solution and process parameters, namely, concentration and flow rate, a variety of non-equilibrium bicompartmental shapes, such as discoid and rod-shaped microparticles are produced in high yields. Optimization of jetting parameters, combined with filtration, results in near-perfect, bicompartmental spherical particles in the size range of 3-5 microm. Simultaneous control over anisotropy, size, shape, and surface structure provides an opportunity to create truly multifunctional microparticles for a variety of biological applications, such as drug delivery, diagnostic assays, and theranostics.

Recent advances with anisotropic particles

“…EHD co-jetting is also based on the laminar flow of two polymeric solutions. Lahann and coworkers have extensively investigated this system [86][87][88][89][90][91][92][93][94], and have prepared bi- [86], tri- [87] and even multicompartmental [91,92] particles and cylinders. The biphasic particles can be induced by the EHD co-jetting of parallel polymer solutions.…”

Porous polymer particles—A comprehensive guide to synthesis, characterization, functionalization and applications

“…It is extensively used for the synthesis of non-crosslinked particles via precipitation of polymers from their solutions [243][244][245][246][247], and a limited number of reports describe monomer polymerization [248][249][250], all of which being about nonporous particles. Loscertales et al [248] successfully electrified a coaxial jet composed of two immiscible liquids, the outer one being a commercial photo-polymerizable resin.…”

Synthesis of colloidal microgels using oxygen-controlled flow lithography

“…5,17 In order to elucidate a complete set of design criteria for maximizing selectivity at the cell and tissue levels, synthesis methods need to afford independent control over the physicochemical properties of the resulting particles. A variety of versatile top-down particle fabrication techniques have emerged in the past few decades, chief among them microuidics, 18 lithography, 19 electrospraying, 20 template stretching, 21,22 or combinations thereof. 23,24 However, not all techniques can freely access the material composition, particle architecture, or length scale (#10 mm) relevant to biological assays, especially cellular uptake, and intravenous injections.…”