title: Taking a deep look: modern microscopy technologies to optimize the design and functionality of biocompatible scaffolds for tissue engineering in regenerative medicine.
abstract: This review focuses on modern nonlinear optical microscopy (NLOM) methods that are increasingly being used in the field of tissue engineering (TE) to image tissue non-invasively and without labelling in depths unreached by conventional microscopy techniques. With NLOM techniques, biomaterial matrices, cultured cells and their produced extracellular matrix may be visualized with high resolution. After introducing classical imaging methodologies such as µCT, MRI, optical coherence tomography, electron microscopy and conventional microscopy two-photon fluorescence (2-PF) and second harmonic generation (SHG) imaging are described in detail (principle, power, limitations) together with their most widely used TE applications. Besides our own cell encapsulation, cell printing and collagen scaffolding systems and their NLOM imaging the most current research articles will be reviewed. These cover imaging of autofluorescence and fluorescence-labelled tissue and biomaterial structures, SHG-based quantitative morphometry of collagen I and other proteins, imaging of vascularization and online monitoring techniques in TE. Finally, some insight is given into state-of-the-art three-photon-based imaging methods (e.g. coherent anti-Stokes Raman scattering, third harmonic generation). This review provides an overview of the powerful and constantly evolving field of multiphoton microscopy, which is a powerful and indispensable tool for the development of artificial tissues in regenerative medicine and which is likely to gain importance also as a means for general diagnostic medical imaging.
authors.affiliation: Department of Chemical and Biological Engineering, Institute of Medical Biotechnology, Friedrich-Alexander-University Erlangen-Nuremberg, Paul-Gordan-Strasse 3, 91052 Erlangen, Germany. martin.vielreicher@mbt.uni-erlangen.de
authors.forename: M
authors.initials: M
authors.lastname: Vielreicher
authors.forename: S
authors.initials: S
authors.lastname: Schürmann
authors.forename: R
authors.initials: R
authors.lastname: Detsch
authors.forename: M A
authors.initials: MA
authors.lastname: Schmidt
authors.forename: A
authors.initials: A
authors.lastname: Buttgereit
authors.forename: A
authors.initials: A
authors.lastname: Boccaccini
authors.forename: O
authors.initials: O
authors.lastname: Friedrich
mesh_terms: D000818:Animals; D006801:Humans; D008853:Microscopy / Q000295:instrumentation / Q000379:methods; D044968:Regenerative Medicine / Q000295:instrumentation / Q000379:methods; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods; D054457:Tissue Scaffolds
keywords: artificial tissues; autofluorescence; biomaterials; extracellular matrix; multiphoton imaging; second harmonic generation