Abstracts of the XIX Congress of the Polish Biophysical Society (PTBF)

@conference{nokey,

title = {Innovative applications of known antioxidants: lipid nanocarriers with α-tocopherols - DSC and AFM analysis},

author = {Andrzej Dudek and Bartosz Pruchnik and Małgorzata Serowik and Teodor Gotszalk and Hanna Pruchnik},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Based on literature and our preliminary studies, tocopherols—like cholesterol—can be used to create liposomal nanocarriers with favourable properties, such as uniform size, controlled shape, and high homogeneity, which support their stability and effectiveness in therapeutic applications [1]. The wide biological activity of tocopherols, especially α-tocopherol, makes them appear to be a competitive component of lipid nanocarriers to cholesterol.  

The α-tocopherol derivatives can affect the mechanical and structural properties of the lipid bilayer of the nanocarriers, hence the precise determination of these changes is crucial for therapeutic applications of liposomes with tocopherols as a drug delivery system

....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Next-Generation Cell Sheet Engineering via Smart Polymer Brush Coatings},

author = {Yana Shymborska and Andrzej Budkowski and Yurij Stetsyshyn},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {The future of regenerative medicine hinges on smart materials that enable precise, non-invasive control of cell behavior. In our work, we develop and characterize advanced temperature- and pH-responsive polymer brush coatings tailored for cell sheet engineering - platforms that not only support robust cell culture but also allow for gentle, enzyme-free detachment of intact cell layers.

We have synthesized thermoresponsive copolymer brushes, such as poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) [P(NIPAM-co-HEMA)] and poly(oligo(ethylene glycol) methacrylate-co-2-hydroxyethyl methacrylate) [P(OEGMA-co-HEMA)], which exhibit tunable lower and upper critical solution temperatures [1]. These coatings enable precise modulation of cell adhesion and spontaneous detachment without enzymatic intervention, preserving cell viability and extracellular matrix integrity. Additionally, we have explored the temperature-responsive properties of pH-sensitive poly(methacrylic acid) (PMAA) grafted brush coatings [2]. These surfaces exhibit controlled wettability, supporting fibroblast culture and highlighting their potential in tissue engineering applications. In our latest work, we have developed Cu-nanoparticle-loaded poly(4-vinylpyridine) (P4VP) brush coatings that integrate antibacterial and thermoresponsive functionalities [3]. These coatings facilitate the harvesting of retinal cell sheets while providing antibacterial properties, demonstrating their potential in ophthalmic regenerative therapies.

Altogether, these smart brush coatings offer a modular and responsive toolkit for next-generation biointerfaces - platforms that meet the growing demand for safer, smarter, and more efficient cell sheet technologies. ...

},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Platinum nanoparticles interact with idarubicin and affect its biological activity},

author = {Marcin Zakrzewski and Patrycja Bełdzińska and Grzegorz Gołuński and Dariusz Wyrzykowski and Katarzyna Bury and Jacek Piosik},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Metallic nanoparticles have attracted the scientific community’s interest since the last century, and among them, platinum nanoparticles (PtNPs) have gained significant attention recently. Due to the variety of size, shape, composition, optical properties and possibility of surface functionalization, they exhibit a broad range of features, therefore they were applied clinically as medicinal, antibacterial or anticancer agents, either alone or in conjunction with drugs, serving as drug carriers [1]. Combining them with chemotherapeutics could result in enhancing the efficacy of the drug and possibly reduce the significance of side effects. With that in mind, we assessed the effects of commercially available platinum nanoparticles on idarubicin (IDA), an antibiotic anticancer agent used in treatment of variety of leukaemias [2]....Firstly, we employed various physicochemical methods, such as dynamic light scattering (DLS) and atomic force microscopy (AFM) to assess the possibility of interactions through aggregation. As IDA is a fluorescent compound we performed spectrofluorimetric analysis to see if there are any close-distance interactions between PtNPs and IDA. Furthermore, we assessed the enthalpy changes using isothermal titration calorimetry (ITC). Finally, the biological effects of PtNPs on IDA were evaluated using Ames Mutagenicity assay with Salmonella enterica serovar Typhimurium TA98 strain. .....

},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {How do platinum nanoparticles affect the biological activity of doxorubicin?},

author = {Patrycja Bełdzińska and Marcin Zakrzewski and Inez Mruk and Natalia Derewońko and Katarzyna Bury and Grzegorz Gołuński and Michał Rychłowski and Jacek Piosik},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Nowadays, platinum nanoparticles (PtNPs) attract much attention due to their properties, such as various sizes and shapes, surface functionalization, and large surface to volume ratio. Importantly, PtNPs are proven to possess anticancer properties and may be used as drug delivery system to provide more efficient treatment [1]. Doxorubicin (DOX), an anthracycline antibiotic, is widely used in treatment of various cancers such as breast, ovarian or hematological malignances. However its usage is limited due to major side effects, particularly severe cardiotoxicity, and drug resistance [2].

Therefore, in this research we decided to investigate whether PtNPs can interact with DOX and consequently influence the biological activity of the drug. Hence, a broad range of physicochemical methods, such as Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS),  Fluorescence Spectroscopy, and biological methods including Ames mutagenicity test and cytotoxicity assay on both non-cancerous and cancerous cell lines were employed.

Firstly, the DLS and AFM results revealed that DOX triggers PtNPs aggregation. In turn, nanoparticles decreased DOX fluorescence and the effect was dilution-independent. Moreover, the Ames assay, showed that PtNPs decrease DOX mutagenicity. Importantly, the results of AlamarBlue cytotoxicity assay revealed that nanoparticles addition promoted cell viability reduction in cancerous cell line in comparison to DOX alone, while they increased the cell viability in non-cancerous cell line....

The confocal microscopy imaging further confirmed that PtNPs had completely opposite effects in the two cell lines. In case of the cancerous MelJuSo cell line, the nanoparticles addition to DOX resulted in fluorescence quenching and a dramatic change in the morphology of the cells. Most of the cells were circular with approximately 1/3 of them showing membrane blebbing which may suggest apoptosis. However, in case of non-cancerous HaCaT cell line, PtNPs improved cell morphology and density of the cell culture compared to DOX alone [3]. 

In summary, the results confirmed that interactions between PtNPs and DOX led to promising effect in cytotoxicity against cancer cells, while simultaneously providing a protective effect on healthy tissue. 

.....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Nucleobindin-2 as a potential modulator of biomineralization},

author = {Dominika Bystranowska and Jarosław Stolarski and Andrzej Ożyhar},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Nucleobindin-2 (Nucb2) is a multifunctional calcium- and DNA-binding protein implicated in various physiological processes, including energy homeostasiss [1], stress response [2], and cancer progression [3, 4]. Structurally, Nucb2 contains EF-hand motifs that confer high affinity for divalent cations, particularly calcium (Ca²⁺), which is crucial for its conformational stability and biological activity [5]. In addition to Ca²⁺, Nucb2 can bind other metal ions such as zinc (Zn²⁺) and magnesium (Mg²⁺) [6], influencing its intracellular localization and interactions with molecular partners. Ion binding alters the  secondary structure of the protein and may modulate its function in calcium-dependent signaling pathways. Recent studies suggest that Nucb2 possesses unique structural features—especially its EF-hand motifs and a putative acidic domain—that may implicate it in biomineralization processes. Biomineralization refers to the biologically controlled deposition of minerals, such as hydroxyapatite in bone or calcium carbonate in marine organisms, which requires tightly regulated ion transport and protein-mineral interactions. The ability of Nucb2 to bind Ca²⁺, Mg²⁺, and Zn²⁺ positions it as a potential modulator of mineral nucleation and growth. Its ion-induced conformational changes may facilitate the spatial organization of ions into stable nucleation sites or influence vesicular transport of mineral precursors. Furthermore, Nucb2 has been detected in tissues undergoing active mineralization, supporting its potential physiological relevance. Although direct evidence for the involvement of Nucb2 in mineral scaffolding remains limited, its structural parallels with other mineralization-associated proteins, such as osteopontin and calmodulin, suggest a possible regulatory function. Here, we present preliminary observations indicating that Nucb2 is involved in mineral-associated cellular processes, possibly through its interaction with divalent metal ions relevant to biomineral formation, and may directly regulate the morphology of the resulting calcium carbonate biocrystals....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Insight into the oligomeric state of the Nudt12 NUDIX protein},

author = {Maciej Zagrodzki and Anna Modrak-Wójcik and Maciej Łukaszewicz},

isbn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Nudt12 is a member of the NUDIX protein superfamily that is characterized by a highly conserved NUDIX motif (GX5EX5[UA]XREX2EEXGU, where U is hydrophobic and X any amino acid). The glutamic acid residues within the NUDIX sequence REUXEE play role in the binding of divalent metal ions required for the catalytic activity of NUDIX enzymes [1]. Nudt12 was initially identified as NADH diphosphatase [2]. It hydrolyses also structures present on 5’ end of RNA (standard m7GpppN cap, and a “metabolite” cap structures as NAD or dpCoA [3, 4]), and is active towards a set of dinucleotide analogs of the standard mRNA cap structure, differing in methylation status of the initial guanosine and the type/methylation of the adjacent nucleotide [5, 6].

Human Nudt12 and its murine homologue are both dimeric proteins with 88% amino acid identity. Resolved crystal structures of hNudt12 and mNudt12 showed the presence of two distinct N- and C-terminal domains, and bound divalent  metal ions (Mg2+ or Cd2+) in NUDIX motif [3, 7]. Dimerization of Nudt12 is essential for its catalytic activity and stability in vivo,  as was demonstrated for the human protein: a designed monomeric mutant of hNudt12 was inactive in decapping assays [3].

The dimeric form of wild-type hNudt12 was confirmed in vitro by size exclusion chromatography (SEC) and analytical ultracentrifugation (AUC) [3]. However our initial AUC experiment for the murine protein mNudt12 showed a dimer-monomer equilibrium. Here, we report SEC analysis of mNudt12 oligomeric states under different experimental conditions (e.g. the presence of divalent ions or increasing protein concentration). Preliminary results confirmed the existence in solution dimeric forms of hNudt12, and a dimer-monomer equilibrium for mNudt12 that could be shifted in the presence of magnesium ions. As mentioned earlier, the monomeric form of hNudt12 is catalytically compromised; therefore, the influence of  the oligomeric state of murine Nudt12 on its enzymatic activity and stability needs further investigation

.....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Cooperativity between the mRNA 5’cap and 4E-BP binding sites in eIF4E explored via tryptophan mutagenesis and fluorescence lifetime analysis},

author = {Aneta Raczyńska and Joanna Żuberek and Anna Modrak-Wójcik},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Specific recognition of the mRNAs 5’ terminal cap structure by the eukaryotic initiation factor eIF4E is the first, rate-limiting, step in the cap-dependent translation [1]. Small 4E-binding proteins (4E-BP1, 4E-BP2, and 4E-BP3) inhibit the translation initiation process by competing with eIF4G initiation factor for the same binding site and by blocking the assembly of the translation machinery [1]. Although the cap and 4E-BP binding sites in eIF4E are spatially distant ( Fig. 1), they do not act independently. According to previous studies, the cap binding to eIF4E makes the affinity of eIF4E to 4E-BP1 significantly stronger, while binding of 4E-BP1 to the cap-eIF4E complex makes the cap dissociation slightly easier [2]. This finding indicates that the binding of either cap or 4E-BP1 induces conformational changes in eIF4E, not only in the region of a given binding site, but also in a distant region encompassing the binding site of the other ligand. ....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Dependence of the fluorescence quantum yield of individual tryptophan residues in a protein on the excitation wavelength},

author = {Karolina Stachurska-Korzeniowska and Jan M. Antosiewicz},

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {Sodium dodecyl sulfate (SDS) is an anionic surfactant that induces changes in both the secondary and tertiary structure of proteins. When examining such changes by fluorescence detection in the protein α-chymotrypsin, it was observed that the fluorescence of the protein, both in the presence and absence of SDS, depends not only on the presence of the surfactant itself but also on the excitation wavelength[1]. In the fluorescence spectrum measurements, a 320 nm cutoff filter was used, meaning that the detected protein fluorescence originated only from tryptophan residues. 

Accordingly, a series of fluorescence spectrum measurements were carried out for both α-chymotrypsin and another protein, α-chymotrypsinogen, in the presence and absence of SDS, at four selected excitation wavelengths: 222, 260, 280, and 295 nm

We hypothesized that the fluorescence emission of individual tryptophan residues in the protein depends on the excitation wavelength. The fluorescence spectra of the proteins were analyzed according to a method found in the literature[2], where the authors presented fluorescence spectra as relative, normalized spectra: the curve for protein + SDS was subtracted from the curve for protein + buffer, and the resulting relative spectrum was then normalized at the short-wavelength minimum to –100 units. The obtained fluorescence spectra are presented in Figure 1. This way of presenting the spectra allows for the analysis of the total effect of the signal change compared to the initial value. 



....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Treatment of flexibility of protein backbone in simulations of protein-ligand interactions using steered molecular dynamics},

author = {Duc Toan Truong and Kiet Ho and Pham Dinh Quoc Huy and Mateusz Chwastyk and Thai Nguyen-Minh and Minh Tho Nguyen },

issn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {To ensure that an external force can break the interaction between a protein and a ligand, the steered molecular dynamics simulation requires a harmonic restrained potential applied to the protein backbone. A usual practice is that all or a certain number of protein’s heavy atoms or Cα atoms are fixed, being restrained by a small force. This present study reveals that while fixing both either all heavy atoms and or all Cα atoms is not a good approach, while fixing a too small number of few atoms sometimes cannot prevent the protein from rotating under the influence of the bulk water layer, and the pulled molecule may smack into the wall of the active site. We found that restraining the Cα atoms under certain conditions is more relevant. Thus, we would propose an alternative solution in which only the Cα atoms of the protein at a distance larger than 1.2 nm from the ligand are restrained. A more flexible, but not too flexible, protein will be expected to lead to a more natural release of the ligand....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}

@conference{nokey,

title = {Biophysical aspects of adipose tissues remodeling during obesity development},

author = {Piotr Deptuła and Łukasz Suprewicz and Mariusz Sawieljew and Robert Bucki},

isbn = {2084-1892},

year  = {2025},

date = {2025-06-25},

urldate = {2025-06-25},

journal = {Current Topics in Biophysics},

volume = {44 (suppl.A)},

publisher = {Polish Biophysical Society and Adam Mickiewicz University},

address = {ul. Uniwersytetu Poznanskiego 2, 61-614 Poznan},

abstract = {During the development of chronic obesity, adipose tissue undergoes significant remodeling, which can result in chronic inflammation leading to fibrosis. This may cause local tissue damage and ultimately initiate dysfunction of multiple organs [1-4].

The aim of this study was to determine the effect of extracellular hyaluronan removal using hyaluronidase on the rheological properties of 3T3-L1 cells during their differentiation process into adipocytes, as well as to perform rheological studies on a lipid-rich adipose tissue hydrogel model. A NanoWizard 4 BioScience AFM (Bruker Nano GmbH, Berlin, Germany), operating in Force Spectroscopy mode, was used to measure the stiffness of confluent cell culture. The Young’s modulus (E) was determined by analyzing force–indentation curves and fitting the data to the Hertz contact model. Rheological characteristics of hydrogels with added lipid elements were evaluated using a strain-controlled Anton Paar MCR702e rheometer (Anton Paar GmbH, Graz, Austria) with a parallel plate setup. The tests quantified the storage modulus (G′) and loss modulus (G″) by measuring the stress required to induce deformation. Two types of shear tests were performed: (1) oscillatory shear strain tests at 1 Hz frequency and 1% amplitude under compressive strain levels of ε = 0%, 10%, 20%, 30%, and 40%; and (2) strain amplitude sweep tests ranging from 0.1% to 100% at a constant frequency of 1 Hz. 

The obtained results indicate that the removal of extracellular hyaluronan affects the mechanical properties of adipocytes. The results may contribute to a better understanding of the complex mechanics of the extracellular matrix of adipose tissue, which may affect the process of cell differentiation.

.....},

type = {Poster},

keywords = {Poster},

pubstate = {published},

tppubtype = {conference}

}