liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Poly-and oligothiophenes: Optical probes for multimodal fluorescent assessment of biological processes
Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

One interesting class of molecules in the research field of imaging biological processes is luminescent conjugated polythiophenes, LCPs. These fluorescent probes have a flexible backbone consisting of repetitive thiophene units. Due to this backbone, the probes possess unique abilities to give rise to different spectral signatures depending on their target and environment. LCPs are a polydispersed material meaning there is an uneven distribution of lengths of the probe. Recently, monodispersed chemically well-defined material denoted luminescent conjugated oligothiophenes, LCOs, with an exact number of repetitive units and distinct sidechain functionalities along the backbone has been developed. LCOs have the advantages of being smaller which leads to higher ability to cross the blood brain barrier. The synthesis of minor chemical alterations is also more simplified due to the well-defined materials.

During my doctoral studies I have used both LCPs and LCOs to study biological processes such as conformational variation of protein aggregates in prion diseases and cellular uptake in normal cells and cancer cells. The research has generally been based on the probes capability to emit light upon irradiation and the interaction with their targets has mainly been assessed through variations in fluorescence intensity, emission-and excitation profiles and fluorescence lifetime decay. These studies verified the utility of LCPs and LCOs for staining and discrimination of both prion strains and cell phenotypes. The results also demonstrated the pronounced influence minor chemical modifications have on the LCO´s staining capacity.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2015. , 54 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1693
National Category
Chemical Sciences Cell and Molecular Biology
Identifiers
URN: urn:nbn:se:liu:diva-121815DOI: 10.3384/diss.diva-121815ISBN: 978-91-7685-986-5 (print)OAI: oai:DiVA.org:liu-121815DiVA: diva2:859490
Public defence
2015-11-06, Planck, Fysikhuset, Campus Valla, Linköping, 10:15 (Swedish)
Opponent
Supervisors
Available from: 2015-10-07 Created: 2015-10-07 Last updated: 2015-10-07Bibliographically approved
List of papers
1. Multimodal fluorescene microscopy of prion strain specific PrP deposits stained by thiophene-bassed amyloid ligands
Open this publication in new window or tab >>Multimodal fluorescene microscopy of prion strain specific PrP deposits stained by thiophene-bassed amyloid ligands
Show others...
2014 (English)In: Prion, ISSN 1933-6896, E-ISSN 1933-690X, Vol. 8, no 4, 319-329 p.Article in journal (Refereed) Published
Abstract [en]

The disease-associated prion protein (PrP) forms aggregates which vary in structural conformation yet share identical primary sequence. These variations in PrP conformation are believed to manifest in prion strains exhibiting distinctly different periods of disease incubation as well as regionally specific aggregate deposition within the brain. The anionic luminescent conjugated polythiophene (LCP), polythiophene acetic acid (PTAA) has previously been used to distinguish PrP deposits associated with distinct mouse adapted strains via distinct fluorescence emission profiles from the dye. Here we employed PTAA and 3 structurally related chemically defined luminescent conjugated oligothiophenes (LCOs) to stain brain tissue sections from mice inoculated with 2 distinct prion strains. Our results showed that in addition to emission spectra, excitation, and fluorescence lifetime imaging microscopy (FLIM) can fruitfully be assessed for optical distinction of PrP deposits associated with distinct prion strains. Our findings support the theory that alterations in LCP/LCO fluorescence are due to distinct conformational restriction of the thiophene backbone upon interaction with PrP aggregates associated with distinct prion strains. We foresee that LCP and LCO staining in combination with multimodal fluorescence microscopy might aid in detecting structural differences among discrete protein aggregates and in linking protein conformational features with disease phenotypes for a variety of neurodegenerative proteinopathies.

Place, publisher, year, edition, pages
Taylor & Francis, 2014
National Category
Chemical Sciences Natural Sciences
Identifiers
urn:nbn:se:liu:diva-106792 (URN)10.4161/pri.29239 (DOI)000348376000006 ()
Available from: 2014-05-23 Created: 2014-05-23 Last updated: 2017-12-05Bibliographically approved
2. Differential vital staining of normal fibroblasts and melanoma cells by an anionic conjugated polyelectrolyte
Open this publication in new window or tab >>Differential vital staining of normal fibroblasts and melanoma cells by an anionic conjugated polyelectrolyte
Show others...
2015 (English)In: Cytometry Part A, ISSN 1552-4922, E-ISSN 1552-4930, Vol. 87, no 3, 262-272 p.Article in journal (Refereed) Published
Abstract [en]

Molecular probes for imaging of live cells are of great interest for studying biological and pathological processes. The anionic luminescent conjugated polythiophene (LCP) polythiophene acetic acid (PTAA), has previously been used for vital staining of cultured fibroblasts as well as transformed cells with results indicating differential staining due to cell phenotype. Herein, we investigated the behavior of PTAA in two normal and five transformed cells lines. PTAA fluorescence in normal cells appeared in a peripheral punctated pattern whereas the probe was more concentrated in a one-sided perinuclear localization in the five transformed cell lines. In fibroblasts, PTAA fluorescence was initially associated with fibronectin and after 24 h partially localized to lysosomes. The uptake and intracellular target in malignant melanoma cells was more ambiguous and the intracellular target of PTAA in melanoma cells is still elusive. PTAA was well tolerated by both fibroblasts and melanoma cells, and microscopic analysis as well as viability assays showed no signs of negative influence on growth. Stained cells maintained their proliferation rate for at least 12 generations. Although the probe itself was nontoxic, photoinduced cellular toxicity was observed in both cell lines upon irradiation directly after staining. However, no cytotoxicity was detected when the cells were irradiated 24 h after staining, indicating that the photoinduced toxicity is dependent on the cellular location of the probe. Overall, these studies certified PTAA as a useful agent for vital staining of cells, and that PTAA can potentially be used to study cancer-related biological and pathological processes.

Place, publisher, year, edition, pages
Wiley: 12 months, 2015
Keyword
Conjugated polyelectrolyte; Fibroblast; Fluorescence; Luminescent conjugated polythiophene; Melanoma; Photoinduced toxicity
National Category
Structural Biology Cell and Molecular Biology
Identifiers
urn:nbn:se:liu:diva-115887 (URN)10.1002/cyto.a.22627 (DOI)000349984200009 ()25605326 (PubMedID)2-s2.0-84923259526 (Scopus ID)
Available from: 2015-03-23 Created: 2015-03-23 Last updated: 2017-12-04
3. Cell Type Related Differences in Staining with Pentameric Thiophene Derivatives
Open this publication in new window or tab >>Cell Type Related Differences in Staining with Pentameric Thiophene Derivatives
Show others...
2014 (English)In: Cytometry Part A, ISSN 1552-4922, E-ISSN 1552-4930, Vol. 85A, no 7, 628-635 p.Article in journal (Refereed) Published
Abstract [en]

Fluorescent compounds capable of staining cells selectively without affecting their viability are gaining importance in biology and medicine. Recently, a new family of optical dyes, denoted luminescent conjugated oligothiophenes (LCOs), has emerged as an interesting class of highly emissive molecules for studying various biological phenomena. Properly functionalized LCOs have been utilized for selective identification of disease-associated protein aggregates and for selective detection of distinct cells. Herein, we present data on differential staining of various cell types, including cancer cells. The differential staining observed with newly developed pentameric LCOs is attributed to distinct side chain functionalities along the thiophene backbone. Employing flow cytometry and fluorescence microscopy we examined a library of LCOs for stainability of a variety of cell lines. Among tested dyes we found promising candidates that showed strong or moderate capability to stain cells to different extent, depending on target cells. Hence, LCOs with diverse imidazole motifs along the thiophene backbone were identified as an interesting class of agents for staining of cancer cells, whereas LCOs with other amino acid side chains along the backbone showed a complete lack of staining for the cells included in the study. Furthermore, for p-HTMI,a LCO functionalized with methylated imidazole moieties, the staining was dependent on the p53 status of the cells, indicating that the molecular target for the dye is a cellular component regulated by p53. We foresee that functionalized LCOs will serve as a new class of optical ligands for fluorescent classification of cells and expand the toolbox of reagents for fluorescent live imaging of different cells.

Place, publisher, year, edition, pages
John Wiley & Sons, 2014
Keyword
cancer stem cells; luminescent conjugated oligothiophenes; fluorescent probes
National Category
Clinical Medicine Chemical Sciences Medical Biotechnology Computer and Information Science
Identifiers
urn:nbn:se:liu:diva-109171 (URN)10.1002/cyto.a.22437 (DOI)000338007700010 ()24500794 (PubMedID)
Available from: 2014-08-12 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
4. An imidazole functionalized pentameric thiophene displays different staining patterns in normal and malignant cells
Open this publication in new window or tab >>An imidazole functionalized pentameric thiophene displays different staining patterns in normal and malignant cells
Show others...
2015 (English)In: Frontiers in Chemistry, E-ISSN 2296-2646, Vol. 3, 58Article in journal (Refereed) Published
Abstract [en]

Molecular tools for fluorescent imaging of cells and their components are vital for understanding the function and activity of cells. Here, we report an imidazole functionalized pentameric oligothiophene, p-HTIm, that can be utilized for fluorescent imaging of cells. p-HTIm fluorescence in normal cells appeared in a peripheral punctate pattern partially co-localized with lysosomes, whereas a one-sided perinuclear Golgi associated localization of the dye was observed in malignant cells. The uptake of p-HTIm was temperature dependent and the intracellular target was reached within 1 h after staining. The ability of p-HTIm to stain cells was reduced when the imidazole side chain was chemically altered, verifying that specific imidazole side-chain functionalities are necessary for achieving the observed cellular staining. Our findings confirm that properly functionalized oligothiophenes can be utilized as fluorescent tools for vital staining of cells and that the selectivity towards distinct intracellular targets are highly dependent on the side-chain functionalities along the conjugated thiophene backbone.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2015
Keyword
Oligothiophenes, fluorescence, cells, imaging, imidazole
National Category
Clinical Medicine Chemical Sciences Medical Biotechnology
Identifiers
urn:nbn:se:liu:diva-121813 (URN)10.3389/fchem.2015.00058 (DOI)000373364600001 ()
Note

Vid tiden för disputation förelåg publikationen som manuskript

Funding agencies:  Swedish Foundation for Strategic Research; GeCONil [POIG.02.03.01-24-099/13]; ERC from the European Research Council

Available from: 2015-10-07 Created: 2015-10-07 Last updated: 2017-12-01Bibliographically approved

Open Access in DiVA

fulltext(1163 kB)183 downloads
File information
File name FULLTEXT01.pdfFile size 1163 kBChecksum SHA-512
73e58a77a5fef8d7cdac3b03da696f2ce0fa0d48d1126420f2fac123efcb0b96d7bd4b1cf5fbb8d05e00788269e2f6d4568b7cc4984110259cf47609d4ed9142
Type fulltextMimetype application/pdf
omslag(5071 kB)18 downloads
File information
File name COVER01.pdfFile size 5071 kBChecksum SHA-512
be587ec4749e29c2ee4debc3d79d736918d74b580709e912059ab0ff31a7da48e58bda8ef9f961909642f44d83214e3112e4548f24829ad075e287e0623c6017
Type coverMimetype application/pdf

Other links

Publisher's full text

Authority records BETA

Magnusson, Karin

Search in DiVA

By author/editor
Magnusson, Karin
By organisation
ChemistryFaculty of Science & Engineering
Chemical SciencesCell and Molecular Biology

Search outside of DiVA

GoogleGoogle Scholar
Total: 183 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 1206 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf