Special Issue "Fluorophores - The Fluorescent Toolbox in Biological and Biomedical Research"

Guest Editor
Dr. Gregor Drummen
Guest Editor for MDPI, Switzerland
E-Mail:
Phone: +49 211 40 51 810
Fax: +49 211 47 45 476
Interests: quantum dots; bionanotechnology; two-photon fluorescence imaging; cellular imaging; fluorescence microscopy; nucleic acids; DNA damage; cancer; cell signaling; radiation biology; oxidative stress; lipids and biomembranes; lipid peroxidation

Dear Colleagues,

Ever since the invention of lenses, man has not only looked into the skies, but also into the realm of the invisible microscopic world of tissues, cells, and micro-organisms. The use of fluorescent labels and the development of various forms of optical microscopy, in particular confocal laser scanning microscopy (CLSM), have significantly advanced our knowledge about the basic mechanisms underpinning biology and the pathophysiological processes that lead to disease. Furthermore, fluorescence-based assays have largely replayed radioactive assays in the lab.

It is intended that this special issue of “Molecules” will consider fundamental physicochemical properties, synthesis and modification, biomedical, imaging and assay applications of fluorophores, from organic dyes to fluorescent nanoparticles and fluorescent proteins. In this respect it should be stressed that the fluorescent molecule always takes centre stage. Previously unpublished experimental, theoretical, prospective, historical, and review papers are solicited on the following and related topics:

• Synthesis and modification of fluorophores
• Physico-chemical and fluorescent properties
• Biocompatibility and cytotoxicity
• Live-cell tracking and imaging
• Whole animal imaging
• FRET, FLIM, FRAP, FLIP et al.
• Applications in cell biology and (bio)medicine
• Fluorescence-based assays and biosensors

Dr. Gregor Drummen
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs).

• fluorophores
• synthesis
• imaging
• fluorescence microscopy
• BODIPY
• FLUORESCEIN
• ALEXA
• fluorescence sensors
• toxicity
• FRET
• FLIM
• FRAP
• correlation spectroscopy
• CLSM
• fluorescence
• quantum dots
• nanoparticles
• super resolution microscopy

Type of Paper: Review 
Title: Fluorescent Nanoprobes Dedicated to in Vivo Imaging: from Preclinical Validation to Clinical Translation 
Authors: Isabelle Texier, Julien Gravier and Fabrice Navarro 
E-Mails: isabelle.texier-nogues@cea.fr (I.T.), julien.gravier@cea.fr (J.G.), fabrice.navarro@cea.fr (F.N.)
Abstract: With the development in the last five years of a large choice of set-ups dedicated to routine in vivo measurements in rodents, fluorescence imaging techniques are becoming essential tools in preclinical studies. Human clinical uses for diagnostic and image-guided surgery are also envisioned in the short term. Fluorescent nanostructures can improve both the signal sensitivity (better in vivo optical properties) and the fluorescence biodistribution (passive "nano" uptake in tumours for instance). A wide range of fluorescent nanoprobes have been designed and tested in preclinical studies for the last few years. They will be reviewed and discussed considering the obstacles that need to be overcome for their potential everyday use in clinics (toxicity, reproducible production on industrial scale, price in the range of health insurance reimbursement). The conjugation of fluorescence imaging with the benefits of nanotechnology should open the way to new medical applications in the near future.

Type of Paper: Review
Title: Like a Bolt from the Blue: Phthalocyanines in Biomedical Research
Authors: Nawal Sekkat ¹, Hubert van den Bergh ³, Tebello Nyokong ² and Norbert Lange ¹
Affiliations: ¹ Laboratory of Pharmaceutics and Biopharmaceutics, Section of Pharmaceutical Sciences, University of Lausanne/Geneva, Geneva, Switzerland
² Department of Chemistry, Rhodes University, Grahamstown 6140, South Africa
³ Laboratory of Photomedicine, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
Abstract: The purpose of this review is to compile preclinical and clinical results available in the literature relating to the Phthalocyanines (Pcs) as Photosensitizers (PS) for Photodynamic Therapy (PDT) and fluorescence imaging in oncology. Indeed, Pcs are excellent candidates in these fields due to their strong absorbance in the NIR region and high chemical and photo- stability. In particular, this is relevant for their activation at the deepest tissue enetration of light resulting in a higher chance for light to reach target cells. However, Pcs present two main limitations, i.e. a strong tendency to aggregate and a low water-solubility. In order to overcome these issues, both chemical tuning and pharmaceutical formulation coupled with tumor targeting strategies were applied. These aspects will be developed in this review for the most extensively studied Pcs during the last 25 years, i.e. Aluminium, Zinc and Silicon based Pcs.

Type of Paper: Article
Title: Li⁺ Selective Podand Type Fluoroionophore Based on the Diphenylsulfoxide Derivative Bearing Two Pyrene Groups
Authors: Yukihiro Nishimura ¹, Tetsuo Takemura ², and Sadao Arai ³
Affiliations: ¹ Department of Chemistry, Tokyo Medical University, 6-1-1Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan; E-Mail: izumidai@tokyo-med.ac.jp
² Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan; E-Mail: ttakemur@rs.kagu.tus.ac.jp
³ Department of Chemistry, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo, 160-8402, Japan; E-Mail: s-arai@tokyo-med.ac.jp
Abstract: A new podand type fluoroionophores having two pyrene moieties 2,2’-bis(1-pyrenylacetyloxy)diphenyl sulfide, 2,2’-bis(1-pyrenylacetyloxy)diphenyl sulfoxide, and 2,2’-bis(1-pyrenylacetyloxy)diphenyl sulfone have synthesized. Theircomplexation behavior toward alkali metal cations was examined byfluorescence spectroscopy. Among these fluoroionophores, 2,2’-bis(1-pyrenylacetyloxy)diphenyl sulfoxide showed high selectivity toward Li⁺.

Type of  Paper: Article
Title: Absorption and Fluorescence Properties of Silyl-SubstitutedNaphthalene Derivatives at 1- and 1,4- Positions
Authors: Hajime Maeda ^1,*, Tomohiro Maeda ², and Kazuhiko Mizuno ^2,*
Affiliations: ¹ Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan,
² Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan; E-Mails:maeda-h@t.kanazawa-u.ac.jp (H.M.) mizuno@chem.osakafu-u.ac.jp (K.M.)
Abstract: Silyl-substituted naphthalene derivatives at 1- and 1,4-positions were synthesized, and their UV absorption, fluorescence, andfluorescence lifetimes were investigated.  Absorption maxima shifted tolonger wavelengths and fluorescence intensities increased by theintroduction of silyl groups at 1- and 1,4- positions of naphthalene.The shift of absorption maxima and increment of fluorescence intensitywas further observed by the additional introduction of methoxy and cyanogroups at 4- and 5-positions. Fluorescence of 9,10-dicyanoanthracene wasefficiently quenched by these naphthalene derivatives, whose rateconstants calculated by Stern-Volmer plot depended on bulkiness of silylgroups on these compounds.