Evolved Colloidosomes Undergoing Cell‐like Autonomous Shape Oscillations with Buckling

Abstract

In living systems, there are many autonomous and oscillatory phenomena to sustain life, such as heart contractions and breathing. At the microscopic level, oscillatory shape deformations of cells are often observed in dynamic behaviors during cell migration and morphogenesis. In many cases, oscillatory behaviors of cells are not simplistic but complex with diverse deformations. So far, we have succeeded in developing self-oscillating polymers and gels, but complex oscillatory behaviors mimicking those of living cells have yet to be reproduced. Herein, we report a cell-like hollow sphere composed of self-oscillating microgels, that is, a colloidosome, that exhibits drastic shape oscillation in addition to swelling/deswelling oscillations driven by an oscillatory reaction. The resulting oscillatory profile waveform becomes markedly more complex than a conventional one. Especially for larger colloidosomes, multiple buckling and moving buckling points are observed to be analogous to cells.

The Horizon of the Emulsion Particulate Strategy: Engineering Hollow Particles for Biomedical Applications

“…[58] Cong and co-workers fabricate pH-and temperature-dual responsive colloidosomes. [54] Copyright 2016, Wiley-VCH. Extrinsic emulsion particulate strategy dominates the shell structures for multifunctional properties.…”

“…In a critical work, a water-in-octanol Pickering emulsion was prepared by self-assembly of P(Nisopropylacrylamide-r-(N-(3-aminopropyl)-methacrylamide)) (P(NIPAAm-r-NAPMAm)) microgels. [54] Subsequently, the emulsion was cross-linked and followed by the conjugations of Ru(bpy) 3 to produce colloidosomes with temperature and redox sensitivity. Upon increasing the temperature to 30 °C, the colloidosomes deswelled because of the membrane dehydration.…”

“…a) Shape changes in response to the altering temperature: i) 30 °C, ii) 10 °C, and iii) temperature remains at 10 °C for more than 120 s. Reproduced with permission. [54] Copyright 2016, Wiley-VCH. b) The sketch and c) optical images of Janus colloidosomes assembly.…”

Chemomechanical Motion of a Self‐Oscillating Gel in a Protic Ionic Liquid

“…[17,18] Our group has developed self-oscillating polymeric materials that convert energy from chemical oscillation of the BZ reaction into mechanical motion of the polymer network. [21][22][23] To apply the self-oscillating polymer to various functional materials such as biomimetic microactuators,there have been various factors to be controlled including amplitude,f requency, temperature range,f ast response,d uration of oscillation, and operation conditions.O nt he basis of the characteristics of the BZ reaction in hydrated PILs,w e hypothesized that PILs are promising for achieving fastdriven chemomechanical oscillation under milder conditions (that is,w ithout using as trong acid). As the hydrophilicity of the polymer changes with the redox state and the LCST is higher in the oxidized state,r edox changes of the Ru(bpy) 3 moiety during the BZ reaction induce cyclic changes of hydration/dehydration of the polymer chains.T hus,acorresponding autonomous swelling-deswelling self-oscillation of the gel starts spontaneously in the BZ reaction solution, without added catalysts or any external on-off switches.Since the initial report, [20] we have systematically developed selfoscillating polymer materials and systems including nanoactuators,polymersomes with self-beating motion, and afunctional fluid exhibiting amoeba-like locomotion.…”

“…[22] Thermo-sensitivity of the microgel particles was analyzed by using dynamic light scattering (DLS). First, P(NIPAAm-co-NAPMAm) microgel particles were prepared by surfactantfree aqueous radical precipitation polymerization, and then Ru(bpy) 3 -NHS was conjugated to the amino group of NAPMAm.…”