ABSTRACT
Multiphoton microscopy (MPM) is a method of molecular imaging and specifically of intravital imaging that is characterized by high spatial resolution in combination with a greater depth of penetration into the tissue. MPM is a multimodal method based on detection of nonlinear optical signals - multiphoton fluorescence and optical harmonics - and also allows imaging with the use of the parameters of fluorescence decay kinetics. This review describes and discusses photophysical processes within major reporter molecules used in MPM with endogenous contrasts and summarizes several modern experiments that illustrate the capabilities of label-free MPM for molecular imaging of biochemical processes in connective tissue and cells.
Subject(s)
Biochemical Phenomena , Cells/metabolism , Connective Tissue/metabolism , Fluorescent Dyes/chemistry , Microscopy, Fluorescence, Multiphoton/methods , Optical Imaging/methods , HumansABSTRACT
Structural dynamics of the fibrous basis of the reparative regenerate during spontaneous skin wound healing comprises multiple stages, it successively transforms from one organization level to another more complex level, forms a multilevel 3D structure including molecular, supramolecular, fibrillar, fiber, and tissue elements. The formed reparative regenerate is integrated with the preserved skin, together they have common fibrous basis consisting of three parts that are different in organization of fibrous structures: atypical (central), tissue organospecific (peripheral), and transitional.
Subject(s)
Collagen/ultrastructure , Regeneration/physiology , Reticulin/ultrastructure , Skin/injuries , Wound Healing/physiology , Animals , Collagen/physiology , Extracellular Matrix/physiology , Extracellular Matrix/ultrastructure , Male , Microscopy, Electron, Transmission , Rats , Rats, Wistar , Remission, Spontaneous , Reticulin/physiology , Skin/ultrastructure , Wounds, Penetrating/physiopathology , Wounds, Penetrating/rehabilitationABSTRACT
We performed comparative analysis of the morphology of chondrocytes in normal cartilage, after their isolation from the tissue, and at different stages of culturing; structural dynamics of cells during culturing was also studied. Significant morphological differences in chondrocytes at the specified stages of their preparation to in vivo use were revealed. Pronounced structural changes (blebbing and cytoplasm swelling) were found in chondrocytes before their implantation, which can affect the formation of cartilage regenerate. The study was performed using light microscopy methods including time-lapse recording of the cell cultures with differential interference Nomarski contrasting combined with transmission electron microscopy.
Subject(s)
Cartilage, Articular/cytology , Chondrocytes/ultrastructure , Tissue Engineering/methods , Animals , Cartilage, Articular/physiology , Chondrocytes/physiology , Femur/cytology , Femur/physiology , Microscopy, Electron, Transmission , Primary Cell Culture , Sheep, Domestic , Time-Lapse ImagingABSTRACT
Multiple-day distraction regenerate contains a number of foci or zones merging into one another with different structural organization of the fibrocellular basis that reflects successive stages of reparative regeneration. At the moment of the last traction, the central part of the regenerate represents a zone of fibrogenesis (growth zone), which is common for the proximal and distal parts of the distraction regenerate. The other zones are paired and symmetrical: zones of angiogenesis, fibrous osteogenesis (primary), and osteogenesis (secondary). The latter include subzones of resorption, secondary osteogenesis, and functional remodeling.
