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Chemical Reviews Feb 2022Progress in optical manipulation has stimulated remarkable advances in a wide range of fields, including materials science, robotics, medical engineering, and... (Review)
Review
Progress in optical manipulation has stimulated remarkable advances in a wide range of fields, including materials science, robotics, medical engineering, and nanotechnology. This Review focuses on an emerging class of optical manipulation techniques, termed heat-mediated optical manipulation. In comparison to conventional optical tweezers that rely on a tightly focused laser beam to trap objects, heat-mediated optical manipulation techniques exploit tailorable optothermo-matter interactions and rich mass transport dynamics to enable versatile control of matter of various compositions, shapes, and sizes. In addition to conventional tweezing, more distinct manipulation modes, including optothermal pulling, nudging, rotating, swimming, oscillating, and walking, have been demonstrated to enhance the functionalities using simple and low-power optics. We start with an introduction to basic physics involved in heat-mediated optical manipulation, highlighting major working mechanisms underpinning a variety of manipulation techniques. Next, we categorize the heat-mediated optical manipulation techniques based on different working mechanisms and discuss working modes, capabilities, and applications for each technique. We conclude this Review with our outlook on current challenges and future opportunities in this rapidly evolving field of heat-mediated optical manipulation.
Topics: Hot Temperature; Light; Nanotechnology; Optical Tweezers; Optics and Photonics
PubMed: 34797041
DOI: 10.1021/acs.chemrev.1c00626 -
Drug Discovery Today Jan 2023The time taken and the cost of producing novel therapeutic drugs presents a significant burden - a typical target-based drug discovery process involves computational... (Review)
Review
The time taken and the cost of producing novel therapeutic drugs presents a significant burden - a typical target-based drug discovery process involves computational screening of drug libraries, compound assays and expensive clinical trials. This review summarises the value of dynamic conformational information obtained by optical tweezers and how this information can target 'undruggable' proteins. Optical tweezers provide insights into the link between biological mechanisms and structural conformations, which can be used in drug discovery. Developing workflows including software and sample preparation will improve throughput, enabling adoption of optical tweezers in biopharma. As a complementary tool, optical tweezers increase the number of drug candidates, improve the understanding of a target's complex structural dynamics and elucidate interactions between compounds and their targets.
Topics: Optical Tweezers; Proteins; Drug Discovery; Molecular Conformation
PubMed: 36396117
DOI: 10.1016/j.drudis.2022.103443 -
Accounts of Chemical Research May 2022Single-molecule mechanochemical sensing (SMMS) is a novel biosensing technique using mechanical force as a signal transduction mechanism. In the mechanochemical sensing,...
Single-molecule mechanochemical sensing (SMMS) is a novel biosensing technique using mechanical force as a signal transduction mechanism. In the mechanochemical sensing, the chemical binding of an analyte molecule to a sensing template is converted to mechanical signals, such as tensile force, of the template. Since mechanical force can be conveniently monitored by single-molecule tools, such as optical tweezers, magnetic tweezers, or Atomic Force Microscopy, mechanochemical sensing is often carried out at the single molecule level. In traditional format of ensemble sensing, sensitivity can be achieved via chemical or electrical amplifications, which are materials intensive and time-consuming. To address these problems, in 2011, we used the principle of mechanochemical coupling in a single molecular template to detect single nucleotide polymorphism (SNP) in DNA fragments. The single-molecule sensitivity in such SMMS strategy allows to removing complex amplification steps, drastically conserving materials and increasing temporal resolution in the sensing. By placing many probing units throughout a single-molecule sensing template, SMMS can have orders of magnitude better efficiency in the materials usage (i.e., high ) with respect to the ensemble biosensing. The SMMS sensing probes also enable topochemical arrangement of different sensing units. By placing these units in a spatiotemporally addressable fashion, have been demonstrated in our lab to detect an expandable set of microRNA targets. Because of the stochastic behavior of single-molecule binding, however, it is challenging for the SMMS to accurately report analyte concentrations in a fixed time window. While multivariate analysis has been shown to rectify background noise due to stochastic nature of single-molecule probes, a template containing an array of sensing units has shown ensemble average behaviors to address the same problem. In this so-called , collective mechanical transitions of many sensing units occur in the SMMS sensing probes, which allows accurate quantification of analytes. For the SMMS to function as a viable sensing approach readily adopted by biosensing communities, the future of the SMMS technique relies on the reduction in the complexity and cost of instrumentation to report mechanical signals. In this account, we first explain the mechanism and main features of the SMMS. We then specify basic elements employed in SMMS. Using DNA as an exemplary SMMS template, we further summarize different types of SMMS which present multiplexing capability and increased throughput. Finally, recent efforts to develop simple and affordable high throughput methods for force generation and measurement are discussed in this Account for potential usage in the mechanochemical sensing.
Topics: Biosensing Techniques; DNA; Mechanical Phenomena; Microscopy, Atomic Force; Optical Tweezers
PubMed: 35420417
DOI: 10.1021/acs.accounts.1c00770 -
International Journal of Molecular... Apr 2024Light is a key environmental component influencing many biological processes, particularly in prokaryotes such as archaea and bacteria. Light control techniques have... (Review)
Review
Light is a key environmental component influencing many biological processes, particularly in prokaryotes such as archaea and bacteria. Light control techniques have revolutionized precise manipulation at molecular and cellular levels in recent years. Bacteria, with adaptability and genetic tractability, are promising candidates for light control studies. This review investigates the mechanisms underlying light activation in bacteria and discusses recent advancements focusing on light control methods and techniques for controlling bacteria. We delve into the mechanisms by which bacteria sense and transduce light signals, including engineered photoreceptors and light-sensitive actuators, and various strategies employed to modulate gene expression, protein function, and bacterial motility. Furthermore, we highlight recent developments in light-integrated methods of controlling microbial responses, such as upconversion nanoparticles and optical tweezers, which can enhance the spatial and temporal control of bacteria and open new horizons for biomedical applications.
Topics: Prokaryotic Cells; Archaea; Nanoparticles; Optical Tweezers
PubMed: 38612810
DOI: 10.3390/ijms25074001 -
Methods in Molecular Biology (Clifton,... 2013This chapter explains the steps necessary to perform laser surgery upon single adherent mammalian cells, where individual organelles are extracted from the cells by...
This chapter explains the steps necessary to perform laser surgery upon single adherent mammalian cells, where individual organelles are extracted from the cells by optical tweezers and the cells are monitored post-surgery to check their viability. Single-cell laser nanosurgery is used in an increasing range of methodologies because it offers great flexibility. Its main advantages are (a) there is not any physical contact with the cells so they remain in a sterile environment, (b) high spatial selectivity so that single organelles can be extracted from specific areas of individual cells, (c) the method can be conducted in the cell's native media, and (d) in comparison to other techniques that target single cells, such as micromanipulators, laser nanosurgery has a comparatively high throughput.
Topics: Animals; CHO Cells; Cricetinae; Cricetulus; Laser Therapy; Nanotechnology; Optical Tweezers
PubMed: 23546666
DOI: 10.1007/978-1-62703-336-7_14 -
Current Opinion in Chemical Biology Dec 2019Optical trapping (synonymous with optical tweezers) has become a core biophysical technique widely used for interrogating fundamental biological processes on size scales... (Review)
Review
Optical trapping (synonymous with optical tweezers) has become a core biophysical technique widely used for interrogating fundamental biological processes on size scales ranging from the single-molecule to the cellular level. Recent advances in nanotechnology have led to the development of 'nanophotonic tweezers,' an exciting new class of 'on-chip' optical traps. Here, we describe how nanophotonic tweezers are making optical trap technology more broadly accessible and bringing unique biosensing and manipulation capabilities to biological applications of optical trapping.
Topics: Biology; Nanotechnology; Optical Tweezers
PubMed: 31678712
DOI: 10.1016/j.cbpa.2019.09.008 -
Nature Communications Nov 2022Accurate assessment of cell stiffness distribution is essential due to the critical role of cell mechanobiology in regulation of vital cellular processes like...
Accurate assessment of cell stiffness distribution is essential due to the critical role of cell mechanobiology in regulation of vital cellular processes like proliferation, adhesion, migration, and motility. Stiffness provides critical information in understanding onset and progress of various diseases, including metastasis and differentiation of cancer. Atomic force microscopy and optical trapping set the gold standard in stiffness measurements. However, their widespread use has been hampered with long processing times, unreliable contact point determination, physical damage to cells, and unsuitability for multiple cell analysis. Here, we demonstrate a simple, fast, label-free, and high-resolution technique using acoustic stimulation and holographic imaging to reconstruct stiffness maps of single cells. We used this acousto-holographic method to determine stiffness maps of HCT116 and CTC-mimicking HCT116 cells and differentiate between them. Our system would enable widespread use of whole-cell stiffness measurements in clinical and research settings for cancer studies, disease modeling, drug testing, and diagnostics.
Topics: Holography; Optical Tweezers; Acoustic Stimulation; Biophysics; Cell Differentiation
PubMed: 36446776
DOI: 10.1038/s41467-022-35075-x -
Trends in Cell Biology Nov 2022Optical tweezers (OT) provide a noninvasive approach for delivering minute physical forces to targeted objects. Controlling such forces in living cells or in vitro... (Review)
Review
Optical tweezers (OT) provide a noninvasive approach for delivering minute physical forces to targeted objects. Controlling such forces in living cells or in vitro preparations allows for the measurement and manipulation of numerous processes relevant to the form and function of cells. As such, OT have made important contributions to our understanding of the structures of proteins and nucleic acids, the interactions that occur between microscopic structures within cells, the choreography of complex processes such as mitosis, and the ways in which cells interact with each other. In this review, we highlight recent contributions made to the field of cell biology using OT and provide basic descriptions of the physics, the methods, and the equipment that made these studies possible.
Topics: Humans; Nucleic Acids; Optical Tweezers; Physics; Proteins
PubMed: 35672197
DOI: 10.1016/j.tcb.2022.05.001 -
Journal of Biomedical Optics Jul 2021Optical trapping is a technique capable of applying minute forces that has been applied to studies spanning single molecules up to microorganisms. (Review)
Review
SIGNIFICANCE
Optical trapping is a technique capable of applying minute forces that has been applied to studies spanning single molecules up to microorganisms.
AIM
The goal of this perspective is to highlight some of the main advances in the last decade in this field that are pertinent for a biomedical audience.
APPROACH
First, the direct determination of forces in optical tweezers and the combination of optical and acoustic traps, which allows studies across different length scales, are discussed. Then, a review of the progress made in the direct trapping of both single-molecules, and even single-viruses, and single cells with optical forces is outlined. Lastly, future directions for this methodology in biophotonics are discussed.
RESULTS
In the 21st century, optical manipulation has expanded its unique capabilities, enabling not only a more detailed study of single molecules and single cells but also of more complex living systems, giving us further insights into important biological activities.
CONCLUSIONS
Optical forces have played a large role in the biomedical landscape leading to exceptional new biological breakthroughs. The continuous advances in the world of optical trapping will certainly lead to further exploitation, including exciting in-vivo experiments.
Topics: Nanotechnology; Optical Tweezers
PubMed: 34235899
DOI: 10.1117/1.JBO.26.7.070602 -
Scientific Reports Jun 2022Optical trapping and patterning cells or microscopic particles is fascinating. We developed a light sheet-based optical tweezer to trap dielectric particles and live...
Optical trapping and patterning cells or microscopic particles is fascinating. We developed a light sheet-based optical tweezer to trap dielectric particles and live HeLa cells. The technique requires the generation of a tightly focussed diffraction-limited light-sheet realized by a combination of cylindrical lens and high NA objective lens. The resultant field is a focussed line (along x-axis) perpendicular to the beam propagation direction (z-axis). This is unlike traditional optical tweezers that are fundamentally point-traps and can trap one particle at a time. Several spherical beads undergoing Brownian motion in the solution are trapped by the lightsheet gradient potential, and the time (to reach trap-centre) is estimated from the video captured at 230 frames/s. High-speed imaging of beads with increasing laser power shows a steady increase in trap stiffness with a maximum of 0.00118 pN/nm at 52.5 mW. This is order less than the traditional point-traps, and hence may be suitable for applications requiring delicate optical forces. On the brighter side, light sheet tweezer (LOT) can simultaneously trap multiple objects with the distinct ability to manipulate them in the transverse (xy) plane via translation and rotation. However, the trapped beads displayed free movement along the light-sheet axis (x-axis), exhibiting a single degree of freedom. Furthermore, the tweezer is used to trap and pattern live HeLa cells in various shapes and structures. Subsequently, the cells were cultured for a prolonged period of time (> 18 h), and cell viability was ascertained. We anticipate that LOT can be used to study constrained dynamics of microscopic particles and help understand the patterned cell growth that has implications in optical imaging, microscopy, and cell biology.
Topics: HeLa Cells; Humans; Lasers; Optical Tweezers
PubMed: 35715431
DOI: 10.1038/s41598-022-13095-3