Programmed Transport and Release of Cells by Self-Propelled Micromotors

Abstract

Autonomous transport and release of bacterial cells by self-propelled micromotors were achieved. The motors consisted of zinc and platinum hemispheres formed on polystyrene beads and moved as a result of simultaneous redox reactions occurring on both metal ends. The highly negative redox potential of zinc enabled the selection of a wide variety of organic redox compounds as fuels, such as methanol and p-benzoquinone. The movement of motors was observed in solutions of fuels. To realize autonomous capture, transport, and release of cargo, a self-assembled monolayer (SAM) was formed on the platinum part of the motor. This SAM could be desorbed by coupling the reaction with the dissolution of zinc, which could also be controlled by adjusting the concentration of Zn(2+) ions. Escherichia coli (E. coli) cells were captured by the motor (due to hydrophobic interactions), transported, and released following SAM desorption at the mixed potential.

Self‐Propelled Micro/Nanoparticle Motors

“…In parallel, the transport of capsules (i.e., poly(lactic‐co‐glycolic acid), PLGA) that were used as drug carriers was also demonstrated. Such capabilities have also been explored in self‐propelled particles, where Zn/Pt spherical micromotors were able to both transport and release E. coli in a controlled manner . The capture relies on the hydrophobic interactions between E. coli and the SAM of long alkyl chain.…”

Bipolar Conducting Polymer Crawlers Based on Triple Symmetry Breaking

“…[1] The common point of all these approaches is that symmetry needs to be broken in one way or the other in order to generate directed motion, [2][3][4][5][6] thus leading to systems which can be used for various applications ranging from biosensing and drug delivery to environmental remediation. [7][8][9][10] In many of these examples locally modified electrokinetics are responsible for the motion, [6,[11][12][13][14] but also other energy sources such as light or magnetic fields have been studied in this context. [15][16][17] One concept which has emerged as an efficient approach to break the symmetry of chemical systems in a straightforward way, and thus to induce either directly or indirectly motion, is bipolar electrochemistry (BPE).…”

Forecastable and Guidable Bubble‐Propelled Microplate Motors for Cell Transport

“…The current problems in this field lie less in the choice of cell types but rather in finding a proper autonomous controlled transport system as well as storing the cells with subsequent proliferation supports . In recent years, significant progress in the field of self‐propelled micromotors was achieved, offering a rich choice of shape, size, motion principles, and fabrication materials for self‐propelled micromotors . The possibility of magnetic guidance, pickup of magnetic nanoparticles, as well as delivery of preloaded cells was demonstrated for tubular microrockets fabricated via a strain engineered process .…”

“…The motion pattern and speed were compared with analytical and numerical simulations of refs . and the literature …”

“…[1,2] In recent years, significant progress in the field of self-propelled micromotors was achieved, offering a rich choice of shape, size, motion principles, and fabrication materials for self-propelled micromotors. [4][5][6] The possibility of magnetic guidance, [7,8] pickup of magnetic nanoparticles, [9] as well as delivery of preloaded cells [10,11] was demonstrated for tubular microrockets fabricated via a strain engineered process. [11] While the concept of delivery published in ref.…”