We constructed a sensor for the determination of Fe2+ and/or Fe3+ ions that consists of a polyaniline layer as an ion-to-electron transducer; on top of it, chelating molecules are deposited (which can selectively chelate specific ions) and protected with a non-biofouling poly(2-methyl-2-oxazoline)s layer. We have shown that our potentiometric sensing layers show a rapid response to the presence of Fe2+ or Fe3+ ions, do not experience interference with other ions (such as Cu2+), and work in a biological environment in the presence of bovine serum albumin (as a model serum protein). The sensing layers detect iron ions in the concentration range from 5 nM to 50 µM.

• Klíčová slova
• analysis, non-biofouling layer, poly(2-methyl-2-oxazoline)s, potentiometry, sensor of Fe2+ or Fe3+ ions,
• MeSH
• aniliny MeSH
• chelátory * MeSH
• elektrody MeSH
• iontově selektivní elektrody * MeSH
• ionty MeSH
• koncentrace vodíkových iontů MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aniliny MeSH
• chelátory * MeSH
• ionty MeSH
• polyaniline MeSH Prohlížeč

Protein-repulsive surfaces modified with ligands for cell adhesion receptors have been widely developed for controlling the cell adhesion and growth in tissue engineering. However, the question of matrix production and deposition by cells on these surfaces has rarely been addressed. In this study, protein-repulsive polydopamine-poly(ethylene oxide) (PDA-PEO) surfaces were functionalized with an RGD-containing peptide (RGD), with a collagen-derived peptide binding fibronectin (Col), or by a combination of these peptides (RGD + Col, ratio 1:1) in concentrations of 90 fmol/cm(2) and 700 fmol/cm(2) for each peptide type. When seeded with vascular endothelial CPAE cells, the PDA-PEO surfaces proved to be completely non-adhesive for cells. On surfaces with lower peptide concentrations and from days 1 to 3 after seeding, cell adhesion and growth was restored practically only on the RGD-modified surface. However, from days 3 to 7, cell adhesion and growth was improved on surfaces modified with Col and with RGD + Col. At higher peptide concentrations, the cell adhesion and growth was markedly improved on all peptide-modified surfaces in both culture intervals. However, the collagen-derived peptide did not increase the expression of fibronectin in the cells. The deposition of fibronectin on the material surface was generally very low and similar on all peptide-modified surfaces. Nevertheless, the RGD + Col surfaces exhibited the highest cell adhesion stability under a dynamic load, which correlated with the highest expression of talin and vinculin in the cells on these surfaces. A combination of RGD + Col therefore seems to be the most promising for surface modification of biomaterials, e.g. vascular prostheses.

• MeSH
• adsorpce MeSH
• biomimetika * MeSH
• buněčná adheze * MeSH
• exprese genu MeSH
• fibronektiny chemie   genetika   MeSH
• indoly chemie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• molekulární sekvence - údaje MeSH
• oligopeptidy chemie   MeSH
• polyethylenglykoly chemie   MeSH
• polymery chemie   MeSH
• povrchové vlastnosti MeSH
• sekvence aminokyselin MeSH
• talin genetika   MeSH
• vinkulin genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fibronektiny MeSH
• indoly MeSH
• oligopeptidy MeSH
• polydopamine MeSH Prohlížeč
• polyethylenglykoly MeSH
• polymery MeSH
• talin MeSH
• vinkulin MeSH

Composite materials based on a titanium support and a thin, alginate hydrogel could be used in bone tissue engineering as a scaffold material that provides biologically active molecules. The main objective of this contribution is to characterize the activation and the functionalization of titanium surfaces by the covalent immobilization of anchoring layers of self-assembled bisphosphonate neridronate monolayers and polymer films of 3-aminopropyltriethoxysilane and biomimetic poly(dopamine). These were further used to bind a bio-functional alginate coating. The success of the titanium surface activation, anchoring layer formation and alginate immobilization, as well as the stability upon immersion under physiological-like conditions, are demonstrated by different surface sensitive techniques such as spectroscopic ellipsometry, infrared reflection-absorption spectroscopy and X-ray photoelectron spectroscopy. The changes in morphology and the established continuity of the layers are examined by scanning electron microscopy, surface profilometry and atomic force microscopy. The changes in hydrophilicity after each modification step are further examined by contact angle goniometry.

• Klíčová slova
• XPS, alginate, biomimetic surfaces, bisphosphonates, neridronate, poly(dopamine), spectroscopic ellipsometry, surface characterization, surface modification, titanium,
• Publikační typ
• časopisecké články MeSH

Nonfouling surfaces capable of reducing protein adsorption are highly desirable in a wide range of applications. Coating of surfaces with poly(ethylene oxide) (PEO), a water-soluble, nontoxic, and nonimmunogenic polymer, is most frequently used to reduce nonspecific protein adsorption. Here we show how to prepare dense PEO brushes on virtually any substrate by tethering PEO to polydopamine (PDA)-modified surfaces. The chain lengths of hetero-bifunctional PEOs were varied in the range of 45-500 oxyethylene units (M(n) = 2000-20,000). End-tethering of PEO chains was performed through amine and thiol headgroups from reactive polymer melts to minimize excluded volume effects. Surface plasmon resonance (SPR) was applied to investigate the adsorption of model protein solutions and complex biologic medium (human blood plasma) to the densely packed PEO brushes. The level of protein adsorption of human serum albumin and fibrinogen solutions was below the detection limit of the SPR measurements for all PEO chains end-tethered to PDA, thus exceeding the protein resistance of PEO layers tethered directly on gold. It was found that the surface resistance to adsorption of lysozyme and human blood plasma increased with increasing length and brush character of the PEO chains end-tethered to PDA with a similar or better resistance in comparison to PEO layers on gold. Furthermore, the chain density, thickness, swelling, and conformation of PEO layers were determined using spectroscopic ellipsometry (SE), dynamic water contact angle (DCA) measurements, infrared reflection-absorption spectroscopy (IRRAS), and vibrational sum-frequency-generation (VSFG) spectroscopy, the latter in air and water.

• MeSH
• adsorpce MeSH
• bioznečištění prevence a kontrola   MeSH
• indoly chemie   MeSH
• lidé MeSH
• muramidasa chemie   MeSH
• polyethylenglykoly chemie   MeSH
• polymery chemie   MeSH
• sérový albumin chemie   MeSH
• voda chemie   MeSH
• vzduch MeSH
• zlato chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• indoly MeSH
• muramidasa MeSH
• polydopamine MeSH Prohlížeč
• polyethylenglykoly MeSH
• polymery MeSH
• sérový albumin MeSH
• voda MeSH
• zlato MeSH