Justyna Fraczyk

3D bioprinting processes show great potential in the context of repair, regeneration, and substituting damaged tissues. Incorporating biomaterials of natural origin into the structure of sodium alginate through adhesive peptides and cellular ligands effectively improves its bioactivity. Despite the advantages and common use of gelatin-based hydrogel materials, their application carries limitations. The possibility of replacing gelatin with collagen during the production of bioinks is becoming promising. Marine organisms are safe, attractive sources from the point of view of ethical restrictions, as well as abundant due to the amount of waste from collagen sources. This work focuses on analyzing the effect of different concentrations of 50-50 mixture of cold and warm water fish collagen in polymer solutions on the physicochemical and mechanical properties of the developed materials, emphasizing their significant impact on cell proliferation in bioprinted constructs. The obtained results demonstrate that increasing the concentration of fish collagen increases the system’s viscosity; at the same time, in the case of the final hydrogel materials, a higher swelling degree and improved mechanical properties can be obtained. Furthermore, the use of 1.5% (w/v) fish collagen in sodium alginate-based bioinks (2A1.5ColF) promotes proliferation and the organization of cells into extensive cellular networks, leading to the formation of tissue structures.

The search for new compounds capable of inhibiting the activity of enzymes involved in the development of neurodegenerative diseases, including Alzheimer’s disease, has attracted continuing interest for many years. Natural isothiocyanates and their synthetic analogs, as well as compounds containing a 1,3,5-triazine core, constitute a group of molecules with complex mechanisms of action involving multiple molecular targets. Although literature data confirm the activity of both isothiocyanates and s-triazines, these two active fragments have not yet been combined, and it remains unclear whether a synergistic effect can be achieved. In this study, 11 novel isothiocyanate–triazine conjugates, consisting of a 1,3,5-triazine core substituted with aliphatic or cyclic secondary amines and a phosphorus analogue of isothiocyanate [6-(isothiocyanatohexyl)phosphonate)ethyl], were synthesized with yields of 46–80%. The pharmacokinetic profiles and parameters related to Lipinski’s rule of five were determined for all compounds. All compounds were evaluated as inhibitors of acetylcholinesterase (AChE) and β-secretase (BACE1). Compound 1i showed the highest inhibitory activity against AChE (IC₅₀ = 0.182 ± 0.02 µM), while compound 1b exhibited the strongest inhibition of BACE1 (IC₅₀ = 8.48 ± 2.18 µM). To explore the potential of these multifunctional derivatives, plausible enzyme-ligand binding models were proposed based on molecular docking simulations.

Triazines, in particular 1,3,5-triazine, have long been the focus of research teams seeking new structures as potential pharmaceuticals. This is evidenced by continuous reports of new libraries of triazine derivatives and publications on them. The main reason for such great interest in this structure is the wide availability of precursors containing the triazine ring, i.e. melamine or trichlorotriazine, the ease of introducing a wide range of diverse substituents into the structure, and the significant biological activity of the s-triazine ring itself. This makes it possible to design complex structures based on the triazine core. The use of the triazine backbone also makes it possible to hybridize already known pharmaceuticals to improve their activity, selectivity, bioavailability or to combat drug resistance. Triazine derivatives have shown promise as herbicides, antibacterial, antifungal, antimalarial or anticancer agents. In this article, the authors focus on new and recently described s-triazine derivatives with potential applications in cancer treatment. Keywords:

The increasing demand for sustainable agriculture and environmental protection has prompted the exploration of innovative methods to valorize byproducts from rapeseed oil production. This review focuses on the application of microorganisms as a promising approach to transforming rapeseed de-oiling residues, such as cake and meal, into valuable products. This review discusses traditional and modern methods of rapeseed oil extraction, the composition and challenges posed by rapeseed byproducts, and the presence of antinutritional components such as glucosinolates, erucic acid, and phytic acid. Microbial applications, including the production of industrial enzymes, enhanced digestibility, and the neutralization of antinutritional factors, are examined as key solutions for waste valorization. Additionally, the role of microbial consortia and genetic modification in optimizing transformation processes is discussed. This review underscores the potential of microorganisms in creating eco-friendly, scalable technologies that contribute to resource efficiency and environmental sustainability in the agricultural and biotechnology sectors.

The aims of this study were to determine whether it is possible to use peptide microarrays obtained using the SPOT technique (immobilized on cellulose) and specific polyclonal antibodies to select fragments that reconstruct the outer sphere of proteins and to ascertain whether the selected peptide fragments can be useful in the study of their protein–protein and/or peptide–protein interactions. Using this approach, epidermal growth factor (EGF) fragments responsible for the interaction with the EGF receptor were searched. A library of EGF fragments immobilized on cellulose was obtained using triazine condensing reagents. Experiments on the interactions with EGFR confirmed the high affinity of the selected peptide fragments. Biological tests on cells showed the lack of cytotoxicity of the EGF fragments. Selected EGF fragments can be used in various areas of medicine.

This work presents the results of research on obtaining chitosan (CS) films containing on their surface ciprofloxacin (CIP). A unique structure was obtained that not only gives new properties to the films, but also changes the way of coverage and structure of the surface. The spectroscopic test showed that in the process of application of CIP on the surface of CS film, CIP was converted from its crystalline form to an amorphic one, hence improving its bioavailability. This improved its scope of microbiological effect. The research was carried out on the reduction of CIP concentration during the process of CIP adhesion to the surface of chitosan films. The antibacterial activity of the CS films with and without the drug was evaluated in relation to Escherichia coli and Staphylococcus aureus, as well as Candida albicans and Penicillium expansum. Changes in the morphology and roughness of membrane surfaces after the antibacterial molecule adhesion process were tested with atomic force microscopy (AFM) and scanning electron microscopy (SEM). Structural analysis of CS and its modifications were confirmed with Fourier-transform spectroscopy in the infrared by an attenuated total reflectance of IR radiation (FTIR-ATR) and solid-state nuclear magnetic resonance (NMR).

This article is a literature review related to the methods of functionalization of carbon fibers for tissue engineering applications. Through physical modification, it is possible to obtain a layer of a chemical compound on the carbon fibers surface and to impart additional properties. On the other hand, chemical modification may lead to the incorporation of appropriate functional groups into the carbon fiber structure, capable of attaching, among others, biologically active compounds. The paper presents the advantages and disadvantages of the carbon fibers modifying methods, with particular emphasis on the use of such modified fibers in medicine.

The cross-linking of polysaccharides is a universal approach to affect their structure and physical properties. Both physical and chemical methods are used for this purpose. Although chemical cross-linking provides good thermal and mechanical stability for the final products, the compounds used as stabilizers can affect the integrity of the cross-linked substances or have toxic properties that limit the applicability of the final products. These risks might be mitigated by using physically cross-linked gels. In the present study, we attempted to obtain hybrid materials based on carbon nonwovens with a layer of cross-linked hyaluronan and peptides that are fragments of bone morphogenetic proteins (BMPs). A variety of cross-linking procedures and cross-linking agents (1,4-butanediamine, citric acid, and BDDE) were tested to find the most optimal method to coat the hydrophobic carbon nonwovens with a hydrophilic hyaluronic acid (HA) layer. Both the use of hyaluronic acid chemically modified with BMP fragments and a physical modification approach (layer-by-layer method) were proposed. The obtained hybrid materials were tested with the spectrometric (MALDI-TOF MS) and spectroscopic methods (IR and 1H-NMR). It was found that the chemical cross-linking of polysaccharides is an effective method for the deposition of a polar active substance on the surface of a hydrophobic carbon nonwoven fabric and that the final material is highly biocompatible.

New scaffold materials composed of biodegradable components are of great interest in regenerative medicine. These materials should be: stable, nontoxic, and biodegrade slowly and steadily, allowing the stable release of biodegradable and biologically active substances. We analyzed peptide-polysaccharide conjugates derived from peptides containing RGD motif (H-RGDS-OH (1), H-GRGDS-NH₂ (2), and cyclo(RGDfC) (3)) and polysaccharides as scaffolds to select the most appropriate biomaterials for application in regenerative medicine. Based on the results of MTT and Ki-67 assays, we can state that the conjugates containing calcium alginate and the ternary nonwoven material were the most supportive of muscle tissue regeneration. Scanning electron microscopy imaging and light microscopy studies with hematoxylin–eosin staining showed that C2C12 cells were able to interact with the tested peptide–polysaccharide conjugates. The release factor (Q) varied depending on both the peptide and the structure of the polysaccharide matrix. LDH, Alamarblue^®, Ki-67, and cell cycle assays indicated that peptides 1 and 2 were characterized by the best biological properties. Conjugates containing chitosan and the ternary polysaccharide nonwoven with peptide 1 exhibited very high antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae. Overall, the results of the study suggested that polysaccharide conjugates with peptides 1 and 2 can be potentially used in regenerative medicine.

Chitosan acquires bacteriostatic properties via protonation of its amino groups. However, much of the literature assumes that chitosan itself inhibits the growth of bacteria. This article presents a comparative study of chitosan nonwovens modified with various acids, including acetic, propionic, butyric, and valeric organic acids, as well as hydrochloric acid. The aim was to determine which acid salts influence the antibacterial and antifungal activity of chitosan-based materials. Two methods were used to modify (formation of ammonium salts) the chitosan nonwovens: First, acid vapors (gassing process) were used to find which salt of chitosan had the best antibacterial properties. Based on the results, the most effective acid was prepared in a solution in ethanol. The influence of the acid concentration in ethanol, the time of treatment of chitosan materials with acid solution, and the rinsing process of modified nonwovens on the antimicrobial activity of the modified materials was investigated. The modified materials were subjected to microbiological tests. Each of the modified materials was placed in bacterial inoculum. The cultures were tested on agar to observe their microbial activity. Toxicity to human red blood cells was also investigated. A reduction in the number of bacterial cells was observed for the S. aureus strain with chitosan salt modified with 10% acetic acid in ethanol. The antibacterial activity of the chitosan salts increased with the percentage of acid salts formed on the surface of the solid material (decreasing numbers of bacterial colonies or no growth). No reduction in growth was observed for the E. coli strain. The chitosan samples were either inactive or completely eliminated the bacterial cells. Antimicrobial activity was observed for chitosan salts with hydrochloric acid and acetic acid. Finally, ¹H-NMR spectroscopy and FTIR spectroscopy were used to confirm the incorporation of the acid groups to the amino groups of chitosan.