Joseph DeSimone, UNC-Chapel Hill

Complex Particles and Patterned Substrates: Opportunities in Life Sciences and Material Science

DeSimone Seminar Flyer

Friday April 11th, 4pm, Phillips 332
(refreshments served in Phillips 330 starting at 3:30)

Abstract: This lecture will focus on opportunities for complex particles and patterned substrates for applications in the life science and in material science areas using a novel fabrication method called PRINT (Particle Replication In Non-wetting Templates). PRINT takes advantage of the unique properties of elastomeric molds comprised of a low surface energy perfluoropolyether network, allowing the production of monodisperse, shape-specific nanoparticles and particle arrays from an extensive range of organic and inorganic liquid precursors.

Life Science: To translate promising molecular discoveries into benefits for patients, we are taking a pharmaco-engineering systems approach to develop the next generation of delivery systems with programmable multi-functional capability. A key strategy is to apply manufacturing technologies from the microelectronics industry to fabricate polymeric delivery systems that are capable of multiple functions. This engineered nature of particle production has a number of advantages over the construction of traditional nanoparticles such as liposomes, dendrimers, and colloidal precipitates. PRINT allows for the precise control over particle size (20 nm to >100 micron), particle shape (spheres, cylinders, discs, toroidal), particle composition (organic/inorganic, solid/porous), particle cargo (hydrophilic or hydrophobic therapeutics, biologicals, imaging agents), particle modulus (stiff, deformable) and particle surface properties (Avidin/biotin complexes, targeting peptides, antibodies, aptamers, cationic/anion charges, Stealth PEG chains). Extensive in vitro and in vivo studies have begun focused on fundamental cellular uptake and intra-cellular trafficking of particles; in vivo biodistribution; and in vivo tissue and cellular targeting for autoimmune disease and cancer treatment/diagnosis.

Material Science: There are many opportunities for PRINT in advanced material science applications. For example, we are collaborating with Heinrich Jaeger (James Frank Institute, University of Chicago) and others to develop a novel robotic system whose dimensions and physical properties have the ability to adapt and reversibly change from solid- to liquid-like. We envision a system that can be structurally rigid but, on command, “dissolves” into a state that is highly malleable or flows like a slurry. As such, the system will be able to morph into a wide range of different configurations and be able to traverse arbitrarily shaped openings. The basic science behind this approach relies on the fact that granular materials, such as sand or dense colloids, undergo dramatic changes in rigidity at the so-called jamming transition. The proposed robotic system, termed a JamBot, will combine smart-particle technologies optimized for reversible interlocking with mechanical and electric-field control of jamming. In addition to particle jamming, the discussion will focus on the details and opportunities for roll-to-roll processing fundamentals and the application of PRINT in patterned arrays and films for use in structural composites, electrets and photovoltaics.