We use computational modeling to design a device that can controllably trap and release particles in solution in response to variations in temperature. The system exploits the thermoresponsive properties of end-grafted fibers and the underlying gel substrate. The fibers mimic the temperature-dependent behavior of biological aptamers, which form a hairpin structure at low temperatures (T) and unfold at higher T, consequently losing their binding affinity. The gel substrate exhibits a lower critical solution temperature and thus, expands at low temperatures and contracts at higher T. By developing a new dissipative particle dynamics simulation, we examine the behavior of this hybrid system in a flowing fluid that contains buoyant nanoparticles. At low T, the expansion of the gel causes the hairpin-shaped fibers to extend into the path of the fluid-driven particle. Exhibiting a high binding affinity for these particles at low temperature, the fibers effectively trap and extract the particles from the surrounding solution. When the temperature is increased, the unfolding of the fiber and collapse of the supporting gel layer cause the particles to be released and transported away from the layer by the applied shear flow. Since the temperature-induced conformational changes of the fiber and polymer gel are reversible, the system can be used repeatedly to “catch and release” particles in solution. Our findings provide guidelines for creating fluidic devices that are effective at purifying contaminated solutions or trapping cells for biological assays.
2016
Harnessing Cooperative Interactions between Thermoresponsive Aptamers and Gels To Trap and Release Nanoparticles. ACS Appl. Mater. Interfaces. 2016;8 (44) :30475-30483.Abstract
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Micropatterned Hydrogel Surface with High-Aspect-Ratio Features for Cell Guidance and Tissue Growth. ACS Appl. Mater. Interfaces. 2016;8 (34) :21939-21945.Abstract
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Computational modeling of oscillating fins that “catch and release“ targeted nanoparticles in bilayer flows. Soft Matter. 2016;12 (5) :1374-1384.Abstract
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Characterization of a Mechanically Tunable Gyroid Photonic Crystal Inspired by the Butterfly Parides Sesostris. Adv. Optical Mater. 2016;4 (1) :99-105.Abstract
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Extremely Stretchable and Fast Self-Healing Hydrogels. Adv. Mater. 2016;28 (23) :4678-4683.Abstract
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Tailoring re-entrant geometry in inverse colloidal monolayers to control surface wettability. J. Mater. Chem. A. 2016;4 (18) :6853-6859.Abstract
. Creating a slippery slope on the surface of medical implants
Transparent antifouling material for improved operative field visibility in endoscopy. Proc. Nat. Acad. Sci. 2016;113 (42) :11676-11681.Abstract
. An unobstructed view into the human body
Aizenberg lab research featured in Science News for Students
Validere to commercialize ‘liquid fingerprinting’ technique
Peter awarded a Veni Lauerate
A Constructive Chemical Conversation. American Scientist. 2016;104 (4) :228-235. Publisher's VersionAbstract
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