Title: Designing Synthetic Microcapsules That Undergo Biomimetic Communication and Autonomous Motion

Abstract

Inspired by the collective behavior of slime molds and amoebas, we designed synthetic cell-like objects that move and self-organize in response to self-generated chemical gradients, thereby exhibiting autochemotaxis. Using computational modeling, we specifically focused on microcapsules that encompass a permeable shell and are localized on an adhesive surface in solution. Lacking any internal machinery, these spherical, fluid-filled shells might resemble the earliest protocells. Our microcapsules do, however, encase particles that can diffuse through the outer shell and into the surrounding fluid. The released particles play two important, physically realizable roles: (1) they affect the permeability of neighboring capsules and (2) they generate adhesion gradients on the underlying surface. Due to feedback mechanisms provided by the released particles, the self-generated adhesion gradients, and hydrodynamic interactions, the capsules undergo collective, self-sustained motion and even exhibit antlike tracking behavior. With the introduction of a chemically patterned stripe on the surface, a triad of capsules can be driven to pick up four-capsule cargo, transport this cargo, and drop off this payload at a designated site. We also modeled a system where the released particles give rise to a particular cycle of negative feedback loops (mimicking the “repressilator” network), which regulates the production of chemicalsmore » within the capsules and hence their release into the solution. By altering the system parameters, three capsules could be controllably driven to self-organize into a stable, close-packed triad that would either translate as a group or remain stationary. Moreover, the stationary triads could be made to switch off after assembly and thus produce minimal quantities of chemicals. Altogether, our models allow us to design a rich variety of self-propelled structures that achieve complex, cooperative behavior through fundamental physicochemical phenomena. The studies can also shed light on factors that enable individual protocells to communicate and self-assemble into larger communities.« less

Authors:

Yashin, Victor V. ^[1]; Kolmakov, German V. ^[2]; Shum, Henry ^[1]; Balazs, Anna C. ^[1]

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+ Show Author Affiliations

1. Chemical Engineering Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
2. Physics Department, New York City College of Technology, Brooklyn, New York 11201, United States

Publication Date:

Fri Aug 21 00:00:00 EDT 2015

Research Org.:

Energy Frontier Research Centers (EFRC) (United States). Center for Bio-Inspired Energy Science (CBES)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences, and Biosciences Division

OSTI Identifier:

1212333

Alternate Identifier(s):

OSTI ID: 1370837

Grant/Contract Number:  

SC0000989

Resource Type:

Published Article

Journal Name:

Langmuir

Additional Journal Information:

Journal Name: Langmuir Journal Volume: 31 Journal Issue: 44; Journal ID: ISSN 0743-7463

Publisher:

American Chemical Society

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; catalysis (homogeneous); solar (photovoltaic); bio-inspired; charge transport; mesostructured materials; materials and chemistry by design; synthesis (novel materials); synthesis (self-assembly); cell signaling; surface interactions; oscillation; polymer science; pharmaceuticals