Effect of Immobilized Thiolated Glycosaminoglycans on Fibronectin Adsorption and Behavior of Fibroblasts

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Polyelectrolyte multilayer (PEM) coatings on biomaterials are applied to tailor adhesion, growth, and function of cells on biomedical implants. Here, biogenic and synthetic polyelectrolytes (PEL) are used for layer-by-layer assembly to study the osteogenic activity of PEM with human osteosarcoma MG-63 cells in a comparative manner. Formation of PEM is achieved with biogenic PEL fibrinogen (FBG) and poly-l-lysine (PLL) as well as biotinylated chondroitin sulfate (BCS) and avidin (AVI), while poly(allylamine hydrochloride) (PAH) and polystyrene sulfonate (PSS) represent a fully synthetic PEM used as a reference system here. Surface plasmon resonance measurements show highest layer mass for FBG/PLL and similar for PSS/PAH and BCS/AVI systems, while water contact angle and zeta potential measurements indicate larger differences for PSS/PAH and FBG/PLL but not for BCS/AVI multilayers. All PEM systems support cell adhesion and growth and promote osteogenic differentiation as well. However, FBG/PLL layers are superior regarding MG-63 cell adhesion during short-term culture, while the BCS/AVI system increases alkaline phosphatase activity in long-term culture. Particularly, a multilayer system based on affinity interaction like BCS/AVI may be useful for controlled presentation of biotinylated growth factors to promote growth and differentiation of cells for biomedical applications.

Section: Resultsmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Characterization Of Multilayer Formation and Surface Propertiesmentioning

confidence: 99%

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Comparative Study of Osteogenic Activity of Multilayers Made of Synthetic and Biogenic Polyelectrolytes

Guduru

Niepel

González-García

et al. 2017

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“…For instance the adsorption of macromolecular cell‐binding ligands like ECM proteins (collagen, laminin, etc.) or glycosaminoglycan (i.e., heparin or hyaluronic acid) is used to improve cell adhesion and proliferation on biomaterials . The multivalent physical interaction of these ligands is relative unspecific and in most cases mainly mediated by electrostatic attraction between contrary charged functional groups .…”

Section: Introductionmentioning

confidence: 99%

“…or glycosaminoglycan (i.e., heparin or hyaluronic acid) is used to improve cell adhesion and proliferation on biomaterials. [14][15][16][17] The multivalent physical interaction of these ligands is relative unspecific and in most cases mainly mediated by electrostatic attraction between contrary charged functional groups. [18][19][20] However passive adsorbed coatings can be unstable under physiological conditions by displacement and/or superposition of unspecific absorbed plasma proteins.…”

Section: Introductionmentioning

confidence: 99%

Generating Aptamers Interacting with Polymeric Surfaces for Biofunctionalization

Schulz

Hecht

Krüger‐Genge

et al. 2016

Common strategies for biofunctionalization of surfaces comprise the immobilization of bioactive molecules used as cell-binding ligands for cell recruitment. Besides covalent binding, multivalent noncovalent physical forces between substrate and ligand are an alternative way to equip surfaces with biomacromolecules. In this study, polymer binding ligands are screened by means of a DNA-based in vitro selection process. As candidate biomaterials poly(ether imide) (PEI), polystyrene, and poly[ethylene-co-(vinyl acetate)] are selected, due to their different chemical structure, but similar macroscopic interface properties, allowing physical interaction with nucleotide bases by varying valences. Multivalent interacting aptamers are successfully enriched by SELEX method and an area-wide surface functionalization is achieved, which can be used for further binding of bioactive molecules. In vitro selection against the polymers result in thymine-dominated aptamer binding motifs. The preferential interaction with thymine is attributed to its chemical structure, connected with a decreased electrostatic repulsion of the π-system and the hydrophobic character maximizing entropy. The aptamer binding stability correlates with available valences for interaction, resulting in a more stable functionalization of PEI.

Effect of Sulfation Route and Subsequent Oxidation on Derivatization Degree and Biocompatibility of Cellulose Sulfates

Strätz

Liedmann

Heinze

et al. 2019

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as wound dressings. [2][3][4] Cellulose sulfates (CS) are well soluble in water and are more susceptible for enzymatic degradation compared to native cellulose. [5] CS have been used in biotechnology, for example, for encapsulation of enzymes and cells. [5] Moreover, it was observed in recent studies that CS possess a similar bioactivity like heparin with regard to inhibition of coagulation, but also when interacting with cytokines that regulate growth and differentiation of cells . [6][7][8] More specifically, it was observed that particularly regioselective sulfation was effective in increasing the binding of CS to the growth factors (GF) FGF-2 and BMP-2 that are related to mitogenic or angiogenic and osteogenic activities, respectively. [8][9][10] In these studies, it was also shown that CS possess a protecting effect on GF stabilizing them against proteolytic digestion by enzymes, which is one explanation for the bioactivity of CS. [11] Since CS represent polyelectrolytes, they have been used for the formation of bioactive surface coatings that guide adhesion and growth of cells using the layerby-layer technique complexing them with chitosan. [12] These observations show that CS possess a wide range of bioactivity that makes them interesting materials for several medical applications in making blood compatible coatings of hemodialysis membranes, coatings of solid implants or tissue engineering scaffolds, but also as components for formation of hydrogels or bioprinting. Sulfated cellulose (CS) represents an interesting biopolymer due to bioactivity comparable to heparin. However, use of CS for making surface coatings or hydrogels requires the presence of reactive groups for covalent reactions.Here, an approach is presented to oxidize cellulose sulfates for subsequent cross-linking reactions with amino groups to form imine bonds. Cellulose is sulfated by direct sulfation or acetosulfation, followed by a Malaprade oxidation. The CS obtained is characterized by elemental analysis and 13 C-NMR spectroscopy. The resulting oxidized cellulose sulfates (oxCS) have different degrees of sulfation ranging from 0.79 to 1.13 and oxidation degrees from 0.18 to 0.34, but also different mass average molecular mass (M W ). Toxicity studies are carried out with mouse 3T3 fibroblasts exposed to aqueous solutions of oxCS. The results show that all oxCS are non-toxic at lower concentrations (0.5 mg mL −1 ), but with both increasing degree of oxidation and concentrations, toxic effects are observed particularly for acetosulfated and lesser for direct sulfated oxCS, which is related to a decrease in the M W of the products. It is concluded that oxCS obtained by direct sulfation with M W above 70 kDa may represent a biocompatible material for the applications suggested above.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.