Zakład Fizyki Makromolekularnej
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od 2020-09-20

Dr Weronika Andrzejewska  | 2011-10 <> 2021-02


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  0000-0002-8565-3099     55653865200     

Publikacje      Projekty                     Seminaria


Wilkowska M., Andrzejewska W., Zieliński R., Kozak M.

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Amyloid beta peptide aggregation process in the presence of sugar-based surfactants- conformational and structural studies The progression of Alzheimer's Disease (AD) is caused by aggregation process of amyloid β peptide (Aβ) [1]. The aggregation mechanism of Aβ peptides is still under discussion, because the process of Aβ oligomerization is relatively fast and it can be affected by many variables [2]. The control of Aβ aggregation is very hard to achieve, but use of selected specific surfactants may contribute to a better understanding of this process. The aim of this study was characterization of the structure and conformational changes in β-amyloid peptides induced by the presence of zwitterionic, sugar-based surfactants comprising a lactose moiety. Several different variants of β-amyloid peptides were selected for the study. The effect of surfactant concentration in solution was tested on Aβ1-42 peptide and its shorter variants. Selected solutions of tested β-amyloid peptides with surfactants were subjected to a series of solution scattering experiments using the synchrotron radiation (SR-SAXS). The SAXS data for these surfactants were collected on P12 beam line of EMBL (DESY). SR-SAXS studies exhibited the structure of various mixed (peptide-surfactant) assemblies. In our study we analyzed also the secondary structure of Aβ peptide in solutions with different concentrations of surfactant, using FTIR spectroscopy and circular dichroism (CD) methods. Atomic force microscopy (AFM) was used to characterize the morphology of Aβ assemblies. Particular attention was paid to analysis of small soluble oligomers that are currently believed to initiate development of brain disfunction in AD.

[1] J. Hardy and D. J. Selkoe, Science, 2002.
[2] J. A. Loureiro, S. Rocha, and M. do C. Pereira, J. Pept. Sci. Off. Publ. Eur. Pept. Soc., 2013.

Acknowledgments: The study was supported by research grant, Grant Diamentowy’’ from Ministry of Science and Higher Education (Poland) - DEC: 0011/DIA2015/44.

Biophysical Journal, 114(3) S1, 221A (2018)

DOI: 10.1016/j.bpj.2017.11.1233   (Pobrane:  2020-07-21)


Andrzejewska W.J., Wilkowska M., Peplińska B., Kozak M.

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Selected polycationic surfactants as sirna carriers for gene therapy So far many drug delivery systems for transfer of nucleic acids in gene therapy have been proposed but there is no universal system for transfer of genetic material into cells. The largest problem in the design of new nucleic acids delivery vehicles is finding a carrier which fulfill such criteria as: stability in complexes with nucleic acids, non-toxicity, non-immunogenicity, ability to safe degradation and easy preparation protocol.

A certain group of polycationic surfactants are able to meet these requirements. Their amphiphilic nature, structure flexibility and the ability to bind to siRNA or DNA oligomers are just some of the advantages. Our past research on selected dicationic compounds as DNA or siRNA delivery systems, indicated that an increase in the number of surfactant subunits is a promised direction to develop new efficient carriers of short nucleic acids.

In this work we present results of the studies of the complexes based on selected novel polycationic surfactants (eg. oligomeric imidazolium derivatives) with a model system - double stranded 21-bp siRNA oligomer. By the use of biophysical methods (electrophoresis, circular dichroism, small angle scattering of synchtorton radiation and cryo-transmission electron microscopy) we examined their complexation capacity, nanostructure of lipoplexes, conformational changes in bound siRNA oligomers and micromorphology of complexes. Our studies have shown the formation of stable systems with promising transfection properties. These systems exhibit various morphologies in frozen state.

Acknowledgments: The study was supported by research grant “PRELUDIUM” from National Science Center (Poland) - UMO-2016/23/N/ST4/01637.

Biophysical Journal, 114(3) S1, 438A (2018)

DOI: 10.1016/j.bpj.2017.11.2424   (Pobrane:  2020-11-05)


Andrzejewska W., Wilkowska M., Chrabąszczewska M., Kozak M.

The study of complexation between dicationic surfactants and the DNA duplex using structural and spectroscopic methods Dicationic (also known as gemini or dimeric) bis-alkylimidazolium surfactants belong to a group of non-viral transfection systems proposed for the successful introduction of different types of nucleic acids (i.e., siRNA, DNA oligomers, and plasmid DNA) into living cells. Our studies reveal the formation of complexes composed of dicationic (gemini) surfactants, 3,3′-[α,ω-(dioxaalkane)]bis(1-dodecylimidazolium)chlorides, and 21 base pair deoxyribonucleic acid duplexes (dsDNA). The studied dsDNA and its complex formation process was analysed by small-angle X-ray scattering (SAXS), molecular modelling (dsDNA), agarose gel electrophoresis (AGE) and circular dichroism spectroscopy (CD). We observed the formation of stable complexes for charge ratio values of p/n > 2. Moreover, we noted conformational changes similar to those observed during the transition of B-DNA to C-DNA, X-DNA, and Z-DNA in several spatial structures (i.e., micellar, hexagonal and cubic) formed in mixtures. The surfactants used in this study were investigated for the influence of dioxaalkane spacer length and the presence of an imidazolium moiety on the complexation process. The complexes formed were stable, and the complexation process was reproducible and efficient. Toxicity tests done on HeLa cells allowed for the determination of non-toxic concentrations of studied surfactants. Transfection tests have confirmed that the studied surfactant systems are effective DNA carriers.

RSC Advances, 7(42), 26006-26018 (2017)

DOI: 10.1039/c6ra24978g   (Pobrane:  2020-10-23)


Moliński A., Zaręba J., Iżykowska J., Skupin M., Andrzejewska W., Jurga S., Kozak M.

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C-60 fullerenes as contrast agents - structural, spectroscopic and nano-toxicity studies Recently, C60 fullerenes have been proposed as contrast agents for MRI method [1]. Especially promising for in vitro and in vivo NMR imaging are their complexes with gadolinum (containing Gd3+ ions entrapped inside the fullerene cage) known also as gadofullerenes [2]. The general problem of carbon nanomaterials is their toxicity towards living cells [3]. The aim of our study is to devise fullerene-based suspensions characterized with low toxicity, which could later be developed into metallofullerene contrast agents. We want to achieve that goal using C60 fullerenes, pluronics to lower the toxicity and phosphatidylcholine derivatives (DMPC or DPPC) to enhance biocompatibility of fullerenes and to stimulate the cellular absorption. In this work we would like to present results of toxicity studies of C60 fullerene systems pluronic modified C60 fullerene systems towards HeLa cells, along with results of structural analyses by AFM and SEM microscopies, FTIR and SAXS. This study was supported by Ministry of Science and Higher Education (Poland), within the project, Najlepsi z najlepszych!”

Biophysical Journal, 112(3) S1, 593A (2017)

DOI: 10.1016/j.bpj.2016.11.3191   (Pobrane:  2020-11-05)


Skupin M., Iżykowska J., Andrzejewska W., Dobies M., Jurga S., Kozak M.

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Interactions of carbon nanotubes stabilized by selected gemini surfactants with model biomembranes Thanks to the extraordinary mechanical strength and high electrical conductivity multiwalled carbon nanotubes are currently used in electronics, medicine (as biomedical sensors, transporters or drugs) as well as in the production of lightweight and durable construction. The aim of this study was to determine the possibility to use different cationic gemini surfactants with different spacer lengths or alkyl chain lengths in more efficient systems for dispersing nanostructures in aqueous solutions. The most important advantages of these systems are their non-immunogenic, biocompatible properties and generally low toxicity . Therefore nanotubes, surrounded by surfactants, have the potential to interact with biological membranes. For this purpose we studied the influence of dispersed CN solution on the phase behavior of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) - a phospholipid most often present in membranes of nerve cells. The microstructure of the stable suspension of carbon nanotubes was investigated using high-resolution Transmission Electron Microscopy and Atomic Force Microscopy. Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) were used to analyze the influence of surfactants studied, used for CN dispersion, on the phase behavior of DMPC bilayers. A series of measurements of toxicity of these systems were performed in HeLa and fibroblast cell cultures. This work was supported by the Ministry of Science and Higher Education, within the project “Najlepsi z najlepszych!” dec.

Biophysical Journal, 112(3) S1, 77A (2017)

DOI: 10.1016/j.bpj.2016.11.460   (Pobrane:  2020-11-05)


Andrzejewska W.J., Skupin M., Skrzypczak A., Kozak M.

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Dicationic and tricationic surfactants as transgene carriers - comparison of their ability to dsdna and sirna binding In last decades, many different compounds have been tested as potential delivery systems of nucleic acids in gene therapy. Compounds subjected for delivery of nucleic acids should be characterized by low toxicity and high ability to form stable complexes with nucleic acids. In practice they should support efficient transfer of therapeutic material (transgene) to the pathological cells. Introduced transgene by interaction with the corresponding cellular genome induce a permanent curative effect. Our previous study indicated, that good transfection properties, have three-dimensional structures formed by self-organized compounds which are structurally similar to the natural lipids. Particularly, new oligomeric amphiphiles, dicationic and tricationic surfactants, seems to be quite promising. The physicochemical properties of these compounds promote their ability to create a stable, biocompatible complexes with dsDNA and siRNA. In this work we present results of structural studies of the complexes formed on the basis of selected novel dicationic or tricationic surfactants with short nucleic acid oligomers (dsDNA and siRNA, 21 bp). These systems were examined by the use of atomic force microscopy (AFM), small angle scattering of synchrotron radiation (SR-SAXS), circular dichroism (CD) and gel electrophoresis. We performed also toxicity tests on HeLa cells. Studies have shown formation of stable systems with the desired biological and chemical properties.

Biophysical Journal, 112(3) S1, 214A (2017)

DOI: 10.1016/j.bpj.2016.11.1183   (Pobrane:  2020-11-05)


Iżykowska J., Skupin M., Andrzejewska W., Dobies M., Jurga S., Kozak M.

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Carbon nanostructures of different spatial geometry: their dispersion and influence on model biological systems The discovery of carbon nanostructures (CN) in the last century has revolutionized science, opening new research opportunities in biophysics, material sciences, biomedicine and pharmacology [1]. Unfortunately, carbon nanomaterials show a strong tendency towards aggregation and poor stability in solutions. Such properties, especially the suspension stability, are critical for bio-applications of carbon nanostructures [2]. Surface functionalization of nanocarbons improves the dispersing properties in water solutions but it may also influence their physicochemical properties [3]. For preparation of biocompatible CN samples we used novel dicationic surfactant (gemini) with imidazole head groups. Nanocarbon suspensions were investigated in the context of their anticancer activity, as well as their application as multimodal contrast/drug delivery agents. Different spatial geometries of CN may be of key importance for designing of the efficient anti-cancer system. Such systems were subjected to the cytotoxicity tests on HeLa cell cultures. The structural properties of selected, the most effective systems based on CN suspensions were characterized by the use of SEM, AFM and NMR methods. This study was supported by the Ministry of Science and Higher Education (Poland), within the project “Najlepsi z najlepszych!”

Biophysical Journal, 112(3) S1, 156A (2017)

DOI: 10.1016/j.bpj.2016.11.857   (Pobrane:  2020-11-05)


Andrzejewska W., Pietralik Z., Skupin M., Kozak M.

Structural studies of the formation of lipoplexes between siRNA and selected bis-imidazolium gemini surfactants Dicationic (gemini) surfactants are agents that can be used for the preparation of stable complexes of nucleic acids, particularly siRNA for therapeutic purposes. In this study, we demonstrated that bis-imidazolium gemini surfactants with variable lengths of dioxyalkyl linker groups (from dioxyethyl to dioxydodecyl) and dodecyl side chains are excellent for the complexation of siRNA. All of these compounds effectively complexed siRNA in a charge ratio range (p/n) of 1.5-10. The low resolution structure of siRNA oligomers was characterised by small angle scattering of synchrotron radiation (SR-SAXS) and ab initio modelling. The structures of the formed complexes were also analysed using SR-SAXS, circular dichroism studies and electrophoretic mobility tests. The most promising agents for complexation with siRNA were the surfactants that contained dioxyethyl and dioxyhexyl spacer groups.

Colloids and Surfaces B: Biointerfaces, 146, 598-606 (2016)

DOI: 10.1016/j.colsurfb.2016.06.062   (Pobrane:  2016-10-11)


Andrzejewska W.J., Skupin M., Skrzypczak A., Kozak M.

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Structural characterization of dsDNA nanocomplexes based on ammonium gemini surfactants One of the most intensively studied groups of chemical compounds are gemini surfactants, because of their specific and attractive properties, especially the capability of stable binding of the nucleic acids, formation of spatial structures with high symmetry and relatively low cytotoxicity. They have found a broad range of applications in medicine, chemical technology, pharmaceutical industry. These complexes can be applied as nonviral transfection delivery systems in gene therapy, a novel and most promising method for the treatment of a broad range of genetic diseases. Dicationic surfactants allow introduction of a transgene without inducing natural immunological response, and release it undamaged inside the cell. However, the successful completion of this process is difficult, because of the need for many studies in order to determine all necessary parameters.
In our study we analysed nanocomplexes of cationic gemini surfactants(1,n-dodecanebis[(oxymethyl)alkyldimethylammonium]chlorides) with DNA oligomers using synchrotron radiation of small angle X-ray scattering, circular dichroism spectroscopy, agarose gel electrophoresis, polarization microscopy and transmission electron microscopy. We also analysed the cytotoxicity of our systems using MTT colorimetric assay on model cell cultures.
We observed the formation of complexes, their morphology, spatial nanostructure, conformation of nucleic acid inside them and influence on the cells. The systems studied were found to be stable and the process of their formation was reproducible.

Biophysical Journal, 110(3) S1, 403A (2016)

DOI: 10.1016/j.bpj.2015.11.2178   (Pobrane:  2020-11-05)


Wolak J., Skupin M., Pietralik Z., Andrzejewska W., Kozak M.

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Studies of zwitterionic lipoplexes - nanosystem based on phospholipids and surfactants as innovative delivery systems for gene therapy The gene therapy is the one of the most promising method of treatment in contemporary medicine. This way of therapy is very useful in the treatment a dozen of incurable or fatal diseases. This method of treatment is leaned on implement a gene into patient's cells with the use of dedicated delivery systems (vectors). The main problem of gene therapy is to find the best vector which will be effective and will be not toxic for human cells. A good approach seems to be use of non-viral vectors like delivery system based on lipid-surfactant mixtures.

The aim of this study was to examine the possible application of selected amphoteric surfactants (zwitterionic alkyl derivatives of sulfobetaine) as complexing agents (with and without helper lipid) for nucleic acids (siRNA, low and high-molecular weight DNA).

The studies of DNA conformation in selected DNA - zwitterionic surfactant lipoplexes were performed using the circular dichroism (CD) spectroscopy. CD spectra were recorded in the spectral range 350 - 200 nm by using J-815 spectrometer (Jasco). The results obtained indicate that the DNA maintains the B-form for wide range of surfactant concentrations in the solution. The structure and organization of lipoplexes was also independently analyzed by the Fourier transform infrared spectroscopy. The absorption spectra for lipoplexes were collected by using FTIR spectrometer BRUKER Tensor 27 in the temperature range 2-40°C. The phase transitions in examined systems were studied by using the differential scanning calorimetry (DSC). Ability of creating of stable complexes in DNA-surfactant systems studied was confirmed using electrophoresis on agarose gel. For all formed stable lipoplexes the complete reduction of electrophoretic mobility was observed. Finally the transfection efficiency of selected systems were also tested on HeLa cells.

Biophysical Journal, 108(2) S1, 545A (2015)

DOI: 10.1016/j.bpj.2014.11.2989   (Pobrane:  2020-11-05)


Andrzejewska W.J., Skupin M., Murawska M., Skrzypczak A., Kozak M.

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The study of complexation process between cationic gemini surfactants and dna using structural and spectroscopic methods Dicationic (gemini) surfactants are intensively studied group of chemical compounds, because of the broad range of applications in medicine, chemical technology or pharmaceutical industry. In solution they can form with nucleic acids the complex structures (lipoplexes), which can be used as drug delivery systems in nonviral transfection. Lipoplexes in gene therapy offer efficient introduction of a therapeutic material to the living cells. Gemini surfactants also allow introduction of a transgene without inducing natural immunological response and release it inside the cell. In our study, we analyzed the process of complexation of cationic gemini surfactants (3.3'- [1,6- (2,n-dioxyalcane)] bis(1-dodecyloxyimidazolium dichlorides)) with DNA, using small angle X-ray scattering, circular dichroism spectroscopy and gel electrophoresis. Surfactants which have been used had of variable length of the spacer group. We observed the formation of stable complexes in these systems and the process of complex formation was reproducible, efficient and immediate.

Biophysical Journal, 108(2) S1, 392A (2015)

DOI: 10.1016/j.bpj.2014.11.2152   (Pobrane:  2020-11-05)


Andrzejewska W., Pietralik Z., Taube M., Skrzypczak A., Kozak M.

Structural and spectroscopic studies on the formation of lipoplexes between DNA and cationic gemini surfactants The process of complex formation between cationic gemini surfactants, 3,3'-[α,ω-(dioxaalkane)]bis(1-dodecylimidazolium) dichloride, with deoxyribonucleic acid (DNA) was studied. The study was performed for ten surfactants having spacer groups of different lengths used in 6 concentrations (5 mM, 2 mM, 1 mM, 0.5 mM, 0.2 mM, 0.1 mM) and a 6.5 μM DNA solution. The complex formation was verified by circular dichroism spectroscopy and gel electrophoresis. The complexes were found to be stable and the process of complex formation was reproducible, efficient and immediate.

Polimery/Polymers, 59(7-8), 569-574 (2014)

DOI: 10.14314/polimery.2014.569
WWW:   (Pobrane:  2021-01-10)


Pietralik Z., Krzysztoń R., Kida W., Andrzejewska W. and Kozak M.

Structure and conformational dynamics of DMPC/dicationic surfactant and DMPC/dicationic surfactant/DNA systems Amphiphilic dicationic surfactants, known as gemini surfactants, are currently studied for gene delivery purposes. The gemini surfactant molecule is composed of two hydrophilic "head" groups attached to hydrophobic chains and connected via molecular linker between them. The influence of different concentrations of 1,5-bis (1-imidazolilo-3-decyloxymethyl) pentane chloride (gemini surfactant) on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayers with and without the presence of DNA was investigated using Fourier transformed infrared (FTIR) and circular dichroism (CD) spectroscopies, small angle scattering of synchrotron radiation and differential scanning calorimetry. With increasing concentration of surfactant in DMPC/DNA systems, a disappearance of pretransition and a decrease in the main phase transition enthalpy and temperature were observed. The increasing intensity of diffraction peaks as a function of surfactant concentration also clearly shows the ability of the surfactant to promote the organisation of lipid bilayers in the multilayer lamellar phase.

International Journal of Molecular Sciences, 14(4), 7642-7659 (2013)

DOI: 10.3390/ijms14047642

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