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Biotensegrity—The Structure of Life
Published in David Lesondak, Angeli Maun Akey, Fascia, Function, and Medical Applications, 2020
According to Benias et al.,32 real-time histological images of living tissues at a depth of 60–70 μm are now a reality made possible by use of confocal laser endoscopy. These images show heretofore unseen reticular patterns throughout the tissues examined, revealing a previously unrecognized fluidic interstitium in the body. Other bespoke research is providing fertile ground for new discoveries, such as the newly described tubular lymphatic vessels identified in the brain using in vivo multiphoton microscopy imaging.33 The bursting of such tubules or pipes (e.g., blood vessels, nerves, and collagens) within us is a rare occurrence and it can be seen in diseased or genetically weakened, helical tubes. These tubules are also tensegrity-based helical structures and move us farther away from linear, mechanical thinking (Figure 8.7).
Application of Nonlinear Microscopy in Life Sciences
Published in Lingyan Shi, Robert R. Alfano, Deep Imaging in Tissue and Biomedical Materials, 2017
Zdenek Svindrych, Ammasi Periasamy
The technical difficulties stem from the basic requirements for efficient 2P excitation, that is, tight focus (diffraction limited, which calls for single-mode propagation of the excitation light) and short pulses with high peak power at the sample are necessary. The large GVD a laser pulse experiences in a long optical fiber can be pre-compensated with suitable pulse shaper, but the small mode area of typical SM fibers (less than 100 μm2) is not compatible with high peak power, thanks to nonlinear pulse broadening (mainly self-phase modulation, SPM) [68]. These limitations can be partially offset using large mode area fibers (often fabricated as photonic-crystal fibers) or multimode fibers provided that only single mode is excited and the light energy does not couple into higher modes. When such fiber is coupled to a distal scanner with a miniature objective lens (often a GRIN lens), such system can be used for multiphoton microscopy. To improve the efficiency with which the fluorescence is collected, double-clad fiber (i.e., the cladding of the central single-mode core acts itself as a large core for fluorescence collection) may be used [2].
Multiphoton imaging of the retina
Published in Pablo Artal, Handbook of Visual Optics, 2017
Robin Sharma, Jennifer J. Hunter
In addition to the conventional approach to multiphoton microscopy, many other sophisticated approaches have been developed for niche applications. For example, in order to suppress background signals, investigators have deployed a scheme called simultaneous spatial and temporal focusing, where the excitation beam’s spectral components are split up spatially into a rainbow beam and then focused through an objective lens onto the sample. This way, the shortest pulse is restricted to the focal volume (Oron et al., 2005; Zhu et al., 2005). Similarly, through the use of rotating microlens disks, cascaded beam splitters and microlens arrays, investigators have demonstrated higher-than-conventional-speed multiphoton microscopy across multiple focal planes for volumetric scanning in thick samples (Andresen et al., 2001; Bewersdorf et al., 1998; Buist et al., 1998; Egner and Hell, 2000; Fittinghoff et al., 2000). More examples are provided in recent review articles on the subject (Carriles et al., 2009; Hoover and Squier, 2013; Oheim et al., 2006).
In vivo dynamics and anti-tumor effects of EpCAM-directed CAR T-cells against brain metastases from lung cancer
Published in OncoImmunology, 2023
Tao Xu, Philipp Karschnia, Bruno Loureiro Cadilha, Sertac Dede, Michael Lorenz, Niklas Seewaldt, Elene Nikolaishvili, Katharina Müller, Jens Blobner, Nico Teske, Julika J. Herold, Kai Rejeski, Sigrid Langer, Hannah Obeck, Theo Lorenzini, Matthias Mulazzani, Wenlong Zhang, Hellen Ishikawa-Ankerhold, Veit R. Buchholz, Marion Subklewe, Niklas Thon, Andreas Straube, Joerg-Christian Tonn, Sebastian Kobold, Louisa von Baumgarten
Metastatic growth was followed by repetitive in vivo microscopy whenever quality of the chronic cranial window allowed. For this purpose, a TrimScope multiphoton microscopy platform (LaVision Biotech TrimScope I) equipped with a MaiTai-laser (wavelength 690–1040 nm; Spectra Physics, Newport) and a 4-times objective (numerical aperture: 0.28; XLFluor, Olympus) or a 20-times water immersion objective (numerical aperture: 0.95; XLUMPlanFl, Olympus) was used. Mice were placed on a heating mat during imaging sessions, anesthesia was established with 1% to 2% isoflurane in oxygen adjusted to the breathing rate, and the cranial plastic ring was tightly secured in a custom-made holding device to ensure minimal movements due to breathing. Prior to in vivo microscopy, 100 µL fluorescein isothiocyanate (FITC)-dextran (10 mg/mL, 2 MDa molecular mass; Sigma-Aldrich) was injected into the tail vein for intravascular plasma staining and, thus, visualization of cerebral blood vessels when appropriate. Recordings were made every 5 μm at a wavelength of 920 nm, and image resolution was set at 1024 × 1024 pixels. For statistical analyses, 3D image stacks with x/y/z-dimensions of 450 × 450 × 400 μm were acquired and imaging started at the cortical surface (as defined by detection of the arachnoid fibers using second harmonic imaging). For dynamic analyses, 3D image stacks with x/y/z-dimensions of 450 × 450 × 66 μm were repetitively acquired over 30 minutes (one recording every 30 seconds) and imaging started 100 µm below the cortical surface.
The role of women scientists in the development of ultrashort pulsed laser technology-based biomedical research in Armenia
Published in International Journal of Radiation Biology, 2022
Gohar Tsakanova, Elina Arakelova, Lusine Matevosyan, Mariam Petrosyan, Seda Gasparyan, Kristine Harutyunyan, Nelly Babayan
The development of near-infrared femtosecond-pulsed lasers allowed to use these types of lasers as a primary source for multiphoton microscopy, which has a number of advantages over the conventional microscopy including confocal microscopy. With the latter, the researchers face a number of challenges. One of them is the penetration depth, the limitation of which occurs due to the light-scattering properties observed in biological tissues. The development of multiphoton excitation techniques allowed to avoid these issues as the light source in near-infrared wavelength range used in these techniques gives the opportunity to conduct deep tissue imaging experiments. This advantages make multiphoton microscopy a powerful tool in many research fields, such as neuroscience, vascular biology, cancer biology. Complementing conventional optical microscopy, it provides an opportunity to conduct in vivo three-dimensional imaging of deep tissue in different mediums, including highly scattering mediums (Brown et al. 2001; Kerr and Denk 2008; Ando et al. 2009; Choi et al. 2011; Yoon and Choi 2017).
Vascular and extracellular matrix remodeling by physical approaches to improve drug delivery at the tumor site
Published in Expert Opinion on Drug Delivery, 2020
Sara Gouarderes, Anne-Françoise Mingotaud, Patricia Vicendo, Laure Gibot
Since hypericin exhibits a stronger affinity to collagen than chlorin e6 [122], it was proposed as a more effective photosensitizer in collagen-rich tissues, such as skin or tumors. Using fluorescence spectroscopy and multiphoton microscopy, Hovhannisyan et al. demonstrated in vitro in collagen gels [123] and in native tissues such as chicken tendons and skin [124] that hypericin – based PDT induced photosensitized irreversible destruction of collagen-based tissues.