In the fast-developing field of tissue engineering there is a constant demand for new materials as scaffolds for cell seeding, which can better mimic a natural extracellular matrix as well as control cell behavior. Among other materials, polysaccharides are widely used for this purpose. One of the main candidates for scaffold fabrication is alginate. However, it lacks sites for cell adhesion. That is why one of the steps toward the development of suitable scaffolds for cells is the introduction of the biofunctionality to the alginate structure. In this work we focused on bone-sialoprotein derived peptide (TYRAY) conjugation to the molecule of alginate. Here the comparison study on four different approaches of peptide conjugation was performed including traditional and novel modification methods, based on 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxy succinimide (EDC/NHS), 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium chloride (DMTMM), thiol-Michael addition and Cu-catalyzed azide-alkyne cycloaddition reactions. It was shown that the combination of the alginate amidation with the use of and subsequent Cu-catalyzed azide-alkyne cycloaddition led to efficient peptide conjugation, which was proven with both NMR and XPS methods. Moreover, the cell culture experiment proved the positive effect of peptide presence on the adhesion of human embryonic stem cells.

• Keywords
• NMR, XPS, adhesion-promoting peptide, alginate, cell adhesion, hESC, polysaccharide modification,
• MeSH
• Alginates chemistry   MeSH
• Amines chemistry   MeSH
• Biomimetics * methods   MeSH
• Cell Adhesion MeSH
• Cell Culture Techniques MeSH
• Cell Line MeSH
• Click Chemistry MeSH
• Magnetic Resonance Spectroscopy MeSH
• Molecular Structure MeSH
• Peptides chemistry   pharmacology   MeSH
• Tissue Engineering * methods   MeSH
• Tissue Scaffolds * MeSH
• Cell Survival drug effects   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alginates MeSH
• Amines MeSH
• Peptides MeSH

Antifouling polymer layers containing extracellular matrix-derived peptide motifs offer promising new options for biomimetic surface engineering. In this contribution, we report the design of antifouling vascular grafts bearing biofunctional peptide motifs for tissue regeneration applications based on hierarchical polymer brushes. Hierarchical diblock poly(methyl ether oligo(ethylene glycol) methacrylate-block-glycidyl methacrylate) brushes bearing azide groups (poly(MeOEGMA-block-GMA-N3)) were grown by surface-initiated atom transfer radical polymerization (SI-ATRP) and functionalized with biomimetic RGD peptide sequences. Varying the conditions of copper-catalyzed alkyne-azide "click" reaction allowed for the immobilization of RGD peptides in a wide surface concentration range. The synthesized hierarchical polymer brushes bearing peptide motifs were characterized in detail using various surface sensitive physicochemical methods. The hierarchical brushes presenting the RGD sequences provided excellent cell adhesion properties and at the same time remained resistant to fouling from blood plasma. The synthesis of anti-fouling hierarchical brushes bearing 1.2 × 103 nmol/cm2 RGD biomimetic sequences has been adapted for the surface modification of commercially available grafts of woven polyethylene terephthalate (PET) fibers. The fiber mesh was endowed with polymerization initiator groups via aminolysis and acylation reactions optimized for the material. The obtained bioactive antifouling vascular grafts promoted the specific adhesion and growth of endothelial cells, thus providing a potential avenue for endothelialization of artificial conduits.

• Keywords
• RGD peptide, X-ray photoelectron spectroscopy, biomimetic surface, hierarchical bioactive polymer brushes, vascular graft, “click”-chemistry,
• MeSH
• Adsorption MeSH
• Amino Acid Motifs MeSH
• Azides chemistry   MeSH
• Coated Materials, Biocompatible * MeSH
• Biomimetic Materials * MeSH
• Cell Adhesion MeSH
• Cell Division MeSH
• Endothelium, Vascular physiology   MeSH
• Blood Vessel Prosthesis * MeSH
• Click Chemistry MeSH
• Human Umbilical Vein Endothelial Cells MeSH
• Immobilized Proteins MeSH
• Silicon MeSH
• Plasma MeSH
• Blood Proteins MeSH
• Humans MeSH
• Oligopeptides chemistry   MeSH
• Polyethylene Terephthalates chemistry   MeSH
• Polymerization * MeSH
• Surface Properties MeSH
• Guided Tissue Regeneration instrumentation   MeSH
• Glass MeSH
• Materials Testing MeSH
• Thrombosis prevention & control   MeSH
• Gold MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• arginyl-glycyl-aspartic acid MeSH Browser
• Azides MeSH
• Coated Materials, Biocompatible * MeSH
• Immobilized Proteins MeSH
• Silicon MeSH
• Blood Proteins MeSH
• Oligopeptides MeSH
• Polyethylene Terephthalates MeSH
• Gold MeSH

Magnetic γ-Fe2O3/CeOx nanoparticles were obtained by basic coprecipitation/oxidation of iron chlorides with hydrogen peroxide, followed by precipitation of Ce(NO3)3 with ammonia. The appearance of CeOx on the magnetic particle surface was confirmed by X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and elemental analysis; a magnetometer was used to measure the magnetic properties of γ-Fe2O3/CeOx. The relatively high saturation magnetization of the particles (41.1 A·m2/kg) enabled magnetic separation. The surface of γ-Fe2O3/CeOx particles was functionalized with PEG-neridronate of two different molecular weights to ensure colloidal stability and biocompatibility. The ability of the particles to affect oxidative stress in hereditary hypertriglyceridemic (HHTg) rats was tested by biological assay of the liver, kidney cortex, and brain tissues. An improvement was observed in both enzymatic [superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)] and non-enzymatic (reduced (GSH) and oxidized (GSSG) glutathione) levels of antioxidant defense and lipid peroxidation parameters [4-hydroxynonenal (4-HNE) and malondialdehyde (MDA)]. The results corresponded with chemical determination of antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, proving that in the animal model γ-Fe2O3/CeOx@PEG2,000 nanoparticles effectively scavenged radicals due to the presence of cerium oxide, in turn decreasing oxidative stress. These particles may therefore have the potential to reduce disorders associated with oxidative stress and inflammation.

• Keywords
• antioxidant, cerium oxide, maghemite, nanoparticles, oxidative stress,
• Publication type
• Journal Article MeSH