Searching for EGF Fragments Recreating the Outer Sphere of the Growth Factor Involved in Receptor Interactions.

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.

Synthesis and Characterization of Antibacterial Chitosan Films with Ciprofloxacin in Acidic Conditions.

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.

Selection of collagen IV fragments forming the outer sphere of the native protein: Assessment of biological activity for regenerative medicine.

The aim of this research was to select the fragments that make up the outer layer of the collagen IV (COL4A6) protein and to assess their potential usefulness for regenerative medicine. It was expected that because protein-protein interactions take place via contact between external domains, the set of peptides forming the outer sphere of collagen IV will determine its interaction with other proteins. Cellulose-immobilized protein fragment libraries treated with polyclonal anti-collagen IV antibodies were used to select the peptides forming the outer sphere of collagen IV.

Coating Methods of Carbon Nonwovens with Cross-Linked Hyaluronic Acid and Its Conjugates with BMP Fragments.

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.

Evaluation of Polysaccharide-Peptide Conjugates Containing the RGD Motif for Potential Use in Muscle Tissue Regeneration.

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 (), H-GRGDS-NH (), and cyclo(RGDfC) ()) and polysaccharides as scaffolds to select the most appropriate biomaterials for application in regenerative medicine.

Antibacterial and Antifungal Properties of Modified Chitosan Nonwovens.

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.

Surface Functionalization of Poly(l-lactide--glycolide) Membranes with RGD-Grafted Poly(2-oxazoline) for Periodontal Tissue Engineering.

Bone tissue defects resulting from periodontal disease are often treated using guided tissue regeneration (GTR). The barrier membranes utilized here should prevent soft tissue infiltration into the bony defect and simultaneously support bone regeneration. In this study, we designed a degradable poly(l-lactide--glycolide) (PLGA) membrane that was surface-modified with cell adhesive arginine-glycine-aspartic acid (RGD) motifs.

Screening of Self-Assembling of Collagen IV Fragments into Stable Structures Potentially Useful in Regenerative Medicine.

The aim of the research was to check whether it is possible to use fragments of type IV collagen to obtain, as a result of self-assembling, stable spatial structures that could be used to prepare new materials useful in regenerative medicine. Collagen IV fragments were obtained by using DMT/NMM/TosO as a coupling reagent. The ability to self-organize and form stable spatial structures was tested by the CD method and microscopic techniques.

1,3,5-Triazine Nitrogen Mustards with Different Peptide Group as Innovative Candidates for AChE and BACE1 Inhibitors.

A series of new analogs of nitrogen mustards (-) containing the 1,3,5-triazine ring substituted with dipeptide residue were synthesized and evaluated for the inhibition of both acetylcholinesterase (AChE) and -secretase (BACE1) enzymes. The AChE inhibitory activity studies were carried out using Ellman's colorimetric method, and the BACE1 inhibitory activity studies were carried out using fluorescence resonance energy transfer (FRET). All compounds displayed considerable AChE and BACE1 inhibition.

Chemical Modification as a Method of Improving Biocompatibility of Carbon Nonwovens.

It was shown that carbon nonwoven fabrics obtained from polyacrylonitrile fibers (PAN) by thermal conversion may be modified on the surface in order to improve their biological compatibility and cellular response, which is particularly important in the regeneration of bone or cartilage tissue. Surface functionalization of carbon nonwovens containing C-C double bonds was carried out using in situ generated diazonium salts derived from aromatic amines containing both electron-acceptor and electron-donor substituents. It was shown that the modification method characteristic for materials containing aromatic structures may be successfully applied to the functionalization of carbon materials.

N-Methylated Analogs of hIAPP Fragments 18-22, 23-27, 33-37 Inhibit Aggregation of the Amyloidogenic Core of the Hormone.

Amylin (hIAPP) aggregation leads to the formation of insoluble deposits and is one of the factors in the development of type II diabetes. The aim of this research was to find N-methylated analogs of the aggregating amylin fragments 18-22, 23-27, and 33-37, which would not themselves be susceptible to aggregation and would inhibit the aggregation of the amyloidogenic cores of the hormone. None of the analogs of fragment 18-22 containing one or two N-methylated amino acid residues showed any tendency to aggregate.

New Human Islet Amyloid Polypeptide Fragments Susceptible to Aggregation.

Human Islet Amyloid Polypeptide (hIAPP) plays a key role in the pathogenesis of type II diabetes. The aim of this research was to search for new amyloidogenic fragments of hIAPP. An initial attempt to predict the amyloidogenic cores of polypeptides/proteins using five different computer programs did not provide conclusive results.

Conjugates of Chitosan and Calcium Alginate with Oligoproline and Oligohydroxyproline Derivatives for Potential Use in Regenerative Medicine.

New materials that are as similar as possible in terms of structure and biology to the extracellular matrix (external environment) of cells are of great interest for regenerative medicine. Oligoproline and oligohydroxyproline derivatives (peptides -) are potential mimetics of collagen fragments. Peptides - have been shown to be similar to the model collagen fragment (H-Gly-Hyp-Pro-Ala-Hyp-Pro-OH, ) in terms of both their spatial structure and biological activity.

Biological Activity of Hydrophilic Extract of Grown on Post-Fermentation Leachate from a Biogas Plant Supplied with Stillage and Maize Silage.

Algae are employed commonly in cosmetics, food and pharmaceuticals, as well as in feed production and biorefinery processes. In this study, post-fermentation leachate from a biogas plant which exploits stillage and maize silage was utilized as a culture medium for . The content of polyphenols in hydrophilic extracts of the biomass was determined, and the extracts were evaluated for their antioxidant activity (DPPH assay), antibacterial activity (against , , , ) and antifungal activity (against , , ).

Conjugates of Copper Alginate with Arginine-Glycine-Aspartic Acid (RGD) for Potential Use in Regenerative Medicine.

Current restrictions on the use of antibiotics, associated with increases in bacterial resistance, require new solutions, including materials with antibacterial properties. In this study, copper alginate fibers obtained using the classic wet method were used to make nonwovens which were modified with arginine-glycine-aspartic acid (RGD) derivatives. Stable polysaccharide-peptide conjugates formed by coupling with 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TosO), and materials with physically embedded RGD derivatives, were obtained.

Insulin Hot-Spot Analogs Formed with -Methylated Amino Acid Residues Inhibit Aggregation of Native Hormone.

In this study, -methylated analogs of hot-spots of insulin were designed and synthesized, in the expectation that they would inhibit the aggregation of both insulin hot-spots and the entire hormone. Synthesis of insulin "amyloidogenic" analogs containing -methylated amino acid residues was performed by microwave-assisted solid phase according to the Fmoc/tert-Bu strategy. As a coupling reagent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TosO) was used.

Fibrous Aggregates of Short Peptides Containing Two Distinct Aromatic Amino Acid Residues.

The aim of the study was the assessment of the ability of short peptides to form aggregates under physiological conditions. The dipeptides studied were derived from different aromatic amino acids (heteroaromatic peptides). Tripeptides were obtained from two distinct aromatic amino acids and cysteine or methionine residue in the C-terminal, N-terminal, or central position.

Synthesis and cellular effects of novel 1,3,5-triazine derivatives in DLD and Ht-29 human colon cancer cell lines.

This study provides new information on the cellular effects of 1,3,5-triazine nitrogen mustards with different peptide groups in DLD and Ht-29 human colon cancer cell lines. A novel series of 2,4,6-trisubstituted 1,3,5-triazine derivatives bearing 2-chloroethyl and oligopeptide moieties was designed and synthesized. The most cytotoxic derivative was triazine with an Ala-Ala-OMe substituent on the ring (compound 7b).

Search for New Aggregable Fragments of Human Insulin.

In this study, three independent methods were used to identify short fragment of both chains of human insulin which are prone for aggregation. In addition, circular dichroism (CD) research was conducted to understand the progress of aggregation over time. The insulin fragments (deca- and pepta-peptides) were obtained by solid-phase synthesis using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TosO) as a coupling reagent.

-Lipidated Amino Acids and Peptides Immobilizedon Cellulose Able to Split Amide Bonds.

N-lipidated short peptides and amino acids immobilized on the cellulose were used ascatalysts cleaved amide bonds under biomimetic conditions. In order to select catalytically mostactive derivatives a library of 156 N-lipidated amino acids, dipeptides and tripeptides immobilizedon cellulose was obtained. The library was synthesized from serine, histidine and glutamic acidpeptides N-acylated with heptanoic, octanoic, hexadecanoic and (E)-octadec-9-enoic acids.

Butanol Synthesis Routes for Biofuel Production: Trends and Perspectives.

Butanol has similar characteristics to gasoline, and could provide an alternative oxygenate to ethanol in blended fuels. Butanol can be produced either via the biotechnological route, using microorganisms such as clostridia, or by the chemical route, using petroleum. Recently, interest has grown in the possibility of catalytic coupling of bioethanol into butanol over various heterogenic systems.

The cellular effects of novel triazine nitrogen mustards in glioblastoma LBC3, LN-18 and LN-229 cell lines.

1,3,5-triazine is an important heterocyclic skeleton for mono, two or three 2-chloroethylamine groups. The study presented here provides novel information on cellular effects of 1,3,5-triazine with mono, two or three 2-chloroethylamine groups in glioblastoma LBC3, LN-18 and LN-229 cell lines. In our study, the most cytotoxic effect was observed in 1,3,5-triazine with three 2-chloroethylamine groups (12f compound).

Study on the Materials Formed by Self-Assembling Hydrophobic, Aromatic Peptides Dedicated to Be Used for Regenerative Medicine.

The aims of this study were to identify the short aromatic peptides which are able to form highly ordered amyloid-like structures in self-assembling processes, to test the influence of length of hydrophobic peptides on tendency to aggregation, and to check if aggregated peptides fulfill requirements expected for materials useful for scaffolding. All tested hydrophobic peptides were prepared on solid phase by using DMT/NMM/TsO as a coupling reagent. The progress of aggregation was studied by set of independent tests.

Orthogonal Functionalization of Nanodiamond Particles after Laser Modification and Treatment with Aromatic Amine Derivatives.

A laser system with a wavelength of 1064 nm was used to generate sp² carbon on the surfaces of nanodiamond particles (NDPs). The modified by microplasma NDPs were analysed using FT-IR and Raman spectroscopy. Raman spectra confirmed that graphitization had occurred on the surfaces of the NDPs.

Towards Intelligent Drug Design System: Application of Artificial Dipeptide Receptor Library in QSAR-Oriented Studies.

The pharmacophore properties of a new series of potential purinoreceptor (P2X) inhibitors determined using a coupled neural network and the partial least squares method with iterative variable elimination (IVE-PLS) are presented in a ligand-based comparative study of the molecular surface by comparative molecular surface analysis (CoMSA). Moreover, we focused on the interpretation of noticeable variations in the potential selectiveness of interactions of individual inhibitor-receptors due to their physicochemical properties; therefore, the library of artificial dipeptide receptors (ADP) was designed and examined. The resulting library response to individual inhibitors was arranged in the array, preprocessed and transformed by the principal component analysis (PCA) and PLS procedures.