| 1. |
- Alm, Kersti, et al.
(författare)
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Cells and holograms : holograms and digital holographic microscopy as a tool to study the morphology of living cells
- 2013
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Ingår i: Holography. - : INTECH. - 9789535111177 ; , s. 335-351
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- We present a method to study the morphology of living, dividing and dying cells using DHM. DHM is a non-invasive, non-destructive and non-phototoxic method which allows the user to perform both qualitative and quantitative measurements of living cells over time. We show here our results on cell division and cell death in single cells. The morphological analyses performed here show changes caused by cell death and cell division, and indicate the possibilities to discriminate between different types of cell death. Cells dying in an apoptosis-like manner display different cell area and cell thickness profiles over time compared to cells dying in a necrosis-like manner, although their volume profiles are very similar. Dividing cells show a characteristic dip in the volume profile, which makes them easily distinguishable. Also, several previous studies show the versatile abilities of DHM. Different cell types have been studied and the morphology has been used to determine cell functionality as well as changes in morphology related to the environment. Cell morphology parameters can be very useful when following the effects of different treatments, the process of differentiation as well as cell growth and cell death. Cell morphology studied by DHM can be useful in toxicology, stem cell and cancer research.
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| 2. |
- Alm, Kersti, et al.
(författare)
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Digital holography and cell studies
- 2011
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Ingår i: Holography, Research and Technologies. - : DKV - Deutscher Kälte- und Klimatechnischer Verein. - 9789533072272 ; , s. 237-252
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Digital holography microscopy (DHM) has developed into a broad field, and one of all the interesting applications is to study cells without staining, labeling or in any other way affecting them. Both fixed and living, dying or dead cells can be studied. The first DHM images showing living cells were published in 2004 and 2005 (Carl et al. 2004, Marquet et al. 2005), making this field of research rather new. Digital holography makes it possible to easily measure cell properties that previously have been very difficult to study, such as cell thickness and volume (Marquet et al. 2005, Mölder et al. 2008). Two of the major advantages of DHM is the 3-D imaging possibility and measurements over time. Digital holography has ben used to study several types of cells, such as nerve cells, red blood cells, stem cells and cancer cells (Emery et al. 2007, Kemper et al. 2006, Langehanenberg et al. 2009) . It has also been applied for studies of cell proliferation, cell movement, sub-cellular structures and cell morphology (Kemper et al. 2009, Yu et al. 2009). Both 2-D and 3-D cell movement can be determined ( Langehanenberg et al. 2009). Even cell viability status can be determined using DHM. Interestingly, it is possible to study both single cells and entire populations simultaneously, allowing for very nuanced studies. Older, well known techniques often require some degree of cell disturbance such as the fluorescent antibody labeling required for fluorescense or confocal microscopy studies. In this paper we will present some of the studies made possible by DHM. We will compare DHM with previously used techniques and discuss the benefits and drawbacks of digital holography cell measurements.
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| 3. |
- El-Schich, Zahra, et al.
(författare)
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Digital holographic microscopy : innovative and non-destructive analysis of living cells
- 2010
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Ingår i: Microscopy: Science, Technology, Applications and Education. - : Formatex Research Center.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Digital holography is a novel technique that has been developed recently to study living cells. The technique is an innovative, non-destructive method with possibilities to study living cells over time. We are investigating cell number, growth, viability and death of adherent cells using digital holography, which is a novel, label-free, imaging technique for biological applications. We have recently demonstrated that digital holography is highly comparable to the conventional manual cell counting method using a hemocytometer (Mölder et al., 2008). Digital holography is a method that gives us information about the refractive index of cells, which can change under different circumstances. The technique is cheap, fast and simple to use. The unique measurable parameters are the cell number, cell area, thickness and volume, which can be transformed to proliferation, migration, viability and cell death. The digital holographic images produced can provide both quantitative and qualitative phase information from a single hologram. Future applications can include real-time cell monitoring of various parameters of cells of different diseases in response to clinically relevant compounds.
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| 4. |
- El-Schich, Zahra, et al.
(författare)
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Discrimination between Breast Cancer Cells and White Blood Cells by Non-Invasive Measurements : Implications for a Novel In Vitro-Based Circulating Tumor Cell Model Using Digital Holographic Cytometry
- 2020
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 10:14
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer is the second most common cancer worldwide. Metastasis is the main reason for death in breast cancer, and today, there is a lack of methods to detect and isolate circulating tumor cells (CTCs), mainly due to their heterogeneity and rarity. There are some systems that are designed to detect rare epithelial cancer cells in whole blood based on the most common marker used today, the epithelial cell adhesion molecule (EpCAM). It has been shown that aggressive breast cancer metastases are of non-epithelial origin and are therefore not always detected using EpCAM as a marker. In the present study, we used an in vitro-based circulating tumor cell model comprising a collection of six breast cancer cell lines and white blood cell lines. We used digital holographic cytometry (DHC) to characterize and distinguish between the different cell types by area, volume and thickness. Here, we present significant differences in cell size-related parameters observed when comparing white blood cells and breast cancer cells by using DHC. In conclusion, DHC can be a powerful diagnostic tool for the characterization of CTCs in the blood.
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| 5. |
- El-Schich, Zahra, et al.
(författare)
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Holography : The Usefulness of Digital Holographic Microscopy for Clinical Diagnostics
- 2017
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Ingår i: Holographic Materials and Optical Systems. - : INTECH. - 9789535130383 ; , s. 319-333
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Digital holographic (DH) microscopy is a digital high-resolution holographic imaging technique with the capacity of quantification of cellular conditions without any staining or labeling of cells. The unique measurable parameters are the cell number, cell area, thickness, and volume, which can be coupled to proliferation, migration, cell cycle analysis, viability, and cell death. The technique is cell friendly, fast and simple to use and has unique imaging capabilities for time-lapse investigations on both the single cell and the cell-population levels. The interest for analyzing specifically cell volume changes with DH microscopy, resulting from cytotoxic treatments, drug response, or apoptosis events has recently increased in popularity. We and others have used DH microscopy showing that the technique has the sensitivity to distinguish between different cells and treatments. Recently, DH microscopy has been used for cellular diagnosis in the clinic, providing support for using the concept of DH, e.g., screening of malaria infection of red blood cells (RBC), cervix cancer screening, and sperm quality. Because of its quick and label-free sample handling, DH microscopy will be an important tool in the future for personalized medicine investigations, determining the optimal therapeutic concentration for both different cancer types and individual treatments.
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| 6. |
- Mölder, Anna, et al.
(författare)
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Non-invasive, label-free cell counting and quantitative analysis of adherent cells using digital holography
- 2008
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Ingår i: Journal of Microscopy. - : Wiley. - 0022-2720 .- 1365-2818. ; 232:2, s. 240-247
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Tidskriftsartikel (refereegranskat)abstract
- Manual cell counting is time consuming and requires a high degree of skill on behalf of the person performing the count. Here we use a technique that utilizes digital holography, allowing label-free and completely non-invasive cell counting directly in cell culture vessels with adherent viable cells. The images produced can provide both quantitative and qualitative phase information from a single hologram. The recently constructed microscope HolomonitorTM (Phase Holographic Imaging AB, Lund, Sweden) combines the commonly used phase contrast microscope with digital holography, the latter giving us the possibility of achieving quantitative information on cellular shape, area, confluence and optical thickness. This project aimed at determining the accuracy and repeatability of cell counting measurements using digital holography compared to the conventional manual cell counting method using a haemocytometer. The collected datawere also used to determine cell size and cellular optical thickness.Theresults showthat digital holography can be used for non-invasive automatic cell counting as precisely as conventional manual cell counting
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| 7. |
- Sternbæk, Louise
(författare)
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Connecting sialic acid expression to cancer cell characteristics : Novel tools for detection, imaging, and analysis
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sialic acid (SA) plays a crucial role in many biological processes. Cell surface SA expression is usually analyzed with antibodies or lectins; however, they are costly and with poor stability. We have used a molecular imprinting technique to synthesize an alternative SA receptor – SA molecularly imprinted polymers(SA-MIPs) with an embedded fluorophore for fluorescent detection of theSA-MIPs. The binding behavior and specificity of SA-MIPs were verified by using lectins and SA conjugates on cancer cell lines, showing that SA-MIPs can be used as an effective tool for SA expression analysis of cancer cells. Digital holographic cytometry (DHC) is a non-phototoxic quantitative phase imaging technique that facilitates the monitoring of living cells over time. We have demonstrated the potential of DHC by mapping cellular parameters, such as cell number, area, thickness, and volume. In addition, cellular parameters possibly depending on sialylation, were evaluated using DHC. Furthermore, the uptake over time of SA-MIPs by macrophages was investigated for any inflammatory and/or cytotoxic responses when administered to phagocytosing cells. Our results indicate that SA-MIPs caused low induction and sparse secretion of inflammatory cytokines, and that reduced cell proliferation was not due to cytotoxicity, but to attenuated cell cycles. These results suggest that SA-MIPs will contribute to the further understanding of cancer cell behavior and can be an asset for in vivo studies.
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| 8. |
- Sternbæk, Louise, et al.
(författare)
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Digital Holographic Cytometry : Macrophage Uptake of Nanoprobes
- 2019
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Ingår i: Imaging and Microscopy. - : John Wiley & Sons. ; :1, s. 21-23
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Digital holographic cytometry (DHC) is a state-of-the-art quantitative phase imaging (QPI) method that permits time-lapse imaging of cells without induced cellular toxicity. DHC platforms equipped with semi-automated image segmentation and analysis software packages for assessing cell behavior are commercially available. In this study we investigate the possible uptake of nanoprobes in macrophages in vitro over time.
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| 9. |
- Sternbæk, Louise, et al.
(författare)
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Molecularly Imprinted Polymers Exhibit Low Cytotoxic and Inflammatory Properties in Macrophages In Vitro
- 2022
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 12, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- Molecularly imprinted polymers (MIPs) against sialic acid (SA) have been developed as a detection tool to target cancer cells. Before proceeding to in vivo studies, a better knowledge of the overall effects of MIPs on the innate immune system is needed. The aim of this study thus was to exemplarily assess whether SA-MIPs lead to inflammatory and/or cytotoxic responses when administered to phagocytosing cells in the innate immune system. The response of monocytic/macrophage cell lines to two different reference particles, Alhydrogel and PLGA, was compared to their response to SA-MIPs. In vitro culture showed a cellular association of SA-MIPs and Alhydrogel, as analyzed by flow cytometry. The reference particle Alhydrogel induced secretion of IL-1β from the monocytic cell line THP-1, whereas almost no secretion was provoked for SA-MIPs. A reduced number of both THP-1 and RAW 264.7 cells were observed after incubation with SA-MIPs and this was not caused by cytotoxicity. Digital holographic cytometry showed that SA-MIP treatment affected cell division, with much fewer cells dividing. Thus, the reduced number of cells after SA-MIP treatment was not linked to SA-MIPs cytotoxicity. In conclusion, SA-MIPs have a low degree of inflammatory properties, are not cytotoxic, and can be applicable for future in vivo studies.
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