Damage-free light-induced assembly of intestinal bacteria with a bubble-mimetic substrate

Abstract

Rapid evaluation of functions in densely assembled bacteria is a crucial issue in the efficient study of symbiotic mechanisms. If the interaction between many living microbes can be controlled and accelerated via remote assembly, a cultivation process requiring a few days can be ommitted, thus leading to a reduction in the time needed to analyze the bacterial functions. Here, we show the rapid, damage-free, and extremely dense light-induced assembly of microbes over a submillimeter area with the “bubble-mimetic substrate (BMS)”. In particular, we successfully assembled 104–105 cells of lactic acid bacteria (Lactobacillus casei), achieving a survival rate higher than 95% within a few minutes without cultivation process. This type of light-induced assembly on substrates like BMS, with the maintenance of the inherent functions of various biological samples, can pave the way for the development of innovative methods for rapid and highly efficient analysis of functions in a variety of microbes.

Light-Induced Condensation of Biofunctional Molecules around Targeted Living Cells to Accelerate Cytosolic Delivery

“…15 In addition, recent reports reveal that several tens of thousands bacterial cells can be manipulated within a few minutes by light-induced convection (LIC) in the absence of thermal damage under the controlled laser heating. 16,17 Here, we demonstrate light-induced acceleration technology to significantly concentrate biologically functional molecules based on LIC from a metallic nanofilm and densely assembled metallic nanoparticles exhibiting plasmonic superradiance, including CPPs, around targeted living cells in cell culture medium, leading to cell membrane penetration and cytosolic delivery even in the case of nanomolar range (e.g., 50 nM) (Figure 1). This technique can be achieved with a much lower sample concentration, leading to effective biological activity.…”

“…For example, the light-induced acceleration of DNA double strands formation as an example of molecular recognition was demonstrated under the optical trapping of DNA-modified gold nanoparticles via complementary DNA and photothermal convection enhanced by infrared absorption of localized surface plasmons in association with their superradiance . In addition, recent reports reveal that several tens of thousands bacterial cells can be manipulated within a few minutes by light-induced convection (LIC) in the absence of thermal damage under the controlled laser heating. , …”

Review of Bubble Applications in Microrobotics: Propulsion, Manipulation, and Assembly

“…Zheng et al proved that nanoparticles could be written directly onto Ag films using optothermally generated surface bubbles (OGSB), and they realized single particle modes and particle combinations with different resolutions and structures [ 35 ]. This technology has attracted extensive attention from scholars in recent years, and the readers are invited to refer to the following references for more detailed discussions on this topic [ 36 , 37 , 38 , 39 , 40 , 41 , 42 ].…”

Optical trapping in micro- and nanoconfinement systems: Role of thermo-fluid dynamics and applications

“…Thermal convection can be actively used to collect target particles near a heated region. In [39], bacteria are accumulated at the stagnant area of the convective flow. By the use of partially-Au-coated particles as a heat source, the thermal damage to the assembled bacteria is avoided.…”