Periodic Reporting for period 2 - Cell-Lasers (Intracellular lasers: Coupling of optical resonances with biological processes)
Période du rapport: 2021-11-01 au 2023-04-30
The specific objectives are to study:
• forces acting within cells,
• properties of natural cavities in lipid droplets and
• intracellular chemical environment.
In the long term Cell-Lasers aims to transform the bio-integrated lasers from being a pure scientific curiosity into powerful tool for the study of biophysical and biochemical processes taking place on a single cell level. Cell-Lasers will significantly improve measurement of several biochemical and biophysical parameters inside cells. By elucidating processes in cells which also lead to diseases, Cell-Lasers will have a strong and long-term impact on medical and social level, by improving quality of life. Lasers inside cells are also very interesting to broad audience and can have large media impact.
The results of this study were published in a peer reviewed article: Gregor Pirnat, and Matjaž Humar, Whispering Gallery-Mode Microdroplet Tensiometry, Advanced Photonics Research 2, 2100129 (2021), DOI: 10.1002/adpr.202100129
Coupling of light with the complex soft matter structures inserted into a laser cavity was studied into detail. This study provides experimental and simulation insights into this coupling. Complex tunable microlasers emitting structured light were made from self-assembled topological liquid crystal superstructures containing topological defects inserted into a thin Fabry-Pérot microcavity (Fig. 2). The topology and geometry of the liquid crystal superstructure determine the structuring of the emitted light by providing complex three dimensionally varying optical axis and order parameter singularities, also affecting the topology of the light polarization.
The results of this study were published in a peer reviewed article: Miha Papič, Urban Mur, Kottoli Poyil Zuhail, Miha Ravnik, Igor Muševič, and Matjaž Humar, Topological liquid crystal superstructures as structured light lasers, Proceedings of the National Academy of Sciences 118, e2110839118 (2021), DOI: 10.1073/pnas.2110839118
Despite numerous novel methods for optical imaging in strongly scattering biological tissues, imaging at single-cell resolution beyond the ballistic light transport regime remains very challenging. We demonstrated that optical microcavity probes embedded inside cells enable three-dimensional localization and tracking of individual cells over extended time periods, as well as sensing of their environment, at depths well beyond the light transport length (Fig. 3). This is achieved by utilizing unique spectral features of the whispering-gallery modes, which are unaffected by tissue scattering, absorption and autofluorescence. In addition, microcavities can be functionalized for simultaneous sensing of various parameters, such as temperature or pH value, which extends their versatility beyond the capabilities of standard fluorescent labels. First author of the paper Aljaž Kavčič presented the results of this work in his master’s thesis, for which he was awarded »Prešernova nagrada« of University of Ljubljana.
The results of this study were published in a peer reviewed article: Aljaž Kavčič, Maja Garvas, Matevž Marinčič, Katrin Unger, Anna Maria Coclite, Boris Majaron, Matjaž Humar, Deep tissue localization and sensing using optical microcavity probes, Nature Communications 13, 1269 (2022), DOI: 10.1038/s41467-022-28904-6
• forces acting within cells,
• properties of natural cavities in lipid droplets and
• intracellular chemical environment.
On all of these three topics we already have very promising results. Some of the results are already summarized in manuscripts and will be submitted soon.