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Sialic acid (SA) is a cell surface glycan, which has a decisive role in many cell activities including differentiation, proliferation, and the immune response. The amount of SA has been found to correlate with cancer, with an upregulation on more aggressive cancers. Therefore, there is a great interest in developing methods for detection of SA on cancer cells. We are screening SA on cancer cell lines by using fluorescent molecularly imprinted polymers, SA-MIPs. Macrophages, which evolve from mono-cytes, are well known for their extraordinary ability to phagocytose foreign objects. This could lead to the hypothesis that the SA-MIPs can be recognized by macrophages as foreign object; thus leading to internalization and potentially degradation.
We have demonstrated that SA-MIPs can be detected after incubation with the RAW macrophage cells, with increasing fluorescence over time. The microscopy analysis shows that the RAW cells ingest the SA-MIP particles. This information is important when planning to use SA-MIPs in future in vivo applications.
Sialic acid (SA) is a cell surface glycan, which has a strong role in many cell activities including differentiation, proliferation, and the immune response. The amount of SA has been found to be correlated with cancer, with an upregulation on more aggressive cancers. Therefore, there is great interest in developing methods for detection of SA on cancer cells. We are screening SA on cancer cell lines by using fluorescent molecularly imprinted polymers, SA-MIPs.Macrophages, which evolve from mono-cytes, are well known for their extraordinary ability to phagocytose foreign objects. This could lead to the hypothesis that the SA-MIPs can be recognized by macrophages as foreign object; thus leading to internalization and potential degradation. We have discovered that SA-MIPs can be detected after incubation with the RAW macrophage cells, with increasing fluorescence over time. The microscopy analysis shows that the RAW cells ingest the SA-MIP particles. This information is important when planning to use SA-MIPs in future in vivo applications.
Sialic acid (SA) is a cell surface glycan, which has been found to be upregulated on more aggressive cancers. Therefore, there is a great interest in developing methods for detection of SA on a great interest in developing methods for detection of SA o on cancer cells. We are screening SA on cell lines by fluorescent molecularly imprinted polymers, SA fluorescent molecularly imprinted polymers, SA fluorescent molecularly imprinted polymers, SA fluorescent molecularly imprinted polymers, SA fluorescent molecularly imprinted polymers, SA fluorescent molecularly imprinted polymers, SA -MIPs. Quantitative phase imaging (QPI) is a digital holographic technique. Various cellular parameters can be visualized and calculated from the particular hologram, including individual cell area, thickness, volume and population confluence and cell counts. The aim was to investigate the possible uptake of SA in macrophage cell lines in in vitro cell cultures and check if they affected the cell.
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.
Sialic acid (SA) is a monosaccharide usually linked to the terminus of glycan chains on the cell surface. It plays a crucial role in many biological processes, and hypersialylation is a common feature in cancer. Lectins are widely used to analyze the cell surface expression of SA.
However, these protein molecules are usually expensive and easily denatured, which calls for the development of alternative glycan-specific receptors and cell imaging technologies. In this study, SA-imprinted fluorescent core-shell molecularly imprinted polymer particles (SA-MIPs) were employed to recognize SA on the cell surface of cancer cell lines. The SA-MIPs improved suspensibility and scattering properties compared with previously used core-shell SA-MIPs. Although SA-imprinting was performed using SA without preference for the alpha-2,3- and alpha-2,6-SA forms, we screened the cancer cell lines analyzed using the lectins Maackia Amurensis Lectin I (MAL I, alpha-2,3-SA) and Sambucus Nigra Lectin (SNA, alpha-2,6-SA). Our results show that the selected cancer cell lines in this study presented a varied binding behavior with the SA-MIPs. The binding pattern of the lectins was also demonstrated. Moreover, two different pentavalent SA conjugates were used to inhibit the binding of the SA-MIPs to breast, skin, and lung cancer cell lines, demonstrating the specificity of the SA-MIPs in both flow cytometry and confocal fluorescence microscopy. We concluded that the synthesized SA-MIPs might be a powerful future tool in the diagnostic analysis of various cancer cells.
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-1b 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.