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In this study, a surface modification strategy using natural biopolymers on titanium is proposed to improve bone healing and promote rapid and successful osseointegration of orthopedic implants. Titania nanotubes were fabricated via an anodization process and the surfaces were further modified with polyelectrolyte multilayers (PEMs) based on Tanfloc (a cationic tannin derivative) and glycosaminoglycans (heparin and hyaluronic acid). Scanning electron microscopy (SEM), water contact angle measurements, and X-ray photoelectron spectroscopy were used to characterize the surfaces. Adipose-derived stem cells (ADSCs) were seeded on the surfaces, and the cell viability, adhesion, and proliferation were investigated. Osteogenesis was induced and osteogenic differentiation of human ADSCs on the surfaces was evaluated via mineralization and protein expression assays, immunofluorescent staining, and SEM. The Tanfloc/heparin PEMs on titania nanotubes improved the rate of osteogenic differentiation of ADSCs as well as the bone mineral deposition, and is therefore a promising approach for use in orthopedic implants., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

To develop hemocompatible surfaces, a cationic tannin derivate (TN) was used to prepare polyelectrolyte multilayers (PEMs) with the glycosaminoglycans heparin (HEP) and chondroitin sulfate (CS). The surface chemistry of the PEMs was characterized using X-ray photoelectron spectroscopy and water contact angle measurements. PEMs assembled with chitosan (CHI) and HEP or CS were used as controls. We investigate the hemocompatibility of PEMs by analyzing the adsorption of key blood serum proteins, adhesion and activation of platelets, and blood clotting kinetics. TN- and CHI-based PEMs adsorb similar amounts of albumin, whereas fibrinogen adsorption was more pronounced on TN-based PEMs, due to strong association with catechol groups. However, TN-based PEMs significantly reduce both platelet adhesion and platelet activation, while CHI-based PEMs promote platelet adhesion and activation. The whole-blood clotting kinetics assay also shows lower blood coagulation on TN-based PEMs. TN is an amphoteric, cationic, condensed tannin derivative with resonance structures. It also contains catechol groups, which are similar to those in mussel adhesive protein. These chemical features enable strong association with fibrinogen, which promotes the platelet-repelling effect. This study provides a new perspective for understanding platelet adhesion and activation on biomaterial surfaces, toward the development of new blood-compatible surfaces using a tannin derivative-based polymer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This study reports the synthesis, characterization and biological properties of films based on poly(vinyl alcohol) (PVA) and a cationic tannin polymer derivative (TN). Films are obtained from polymeric blends by tuning the PVA/TN weight ratios. The materials are characterized through infrared spectroscopy, X-ray photoelectron spectroscopy, contact angle measurements, mechanical analyses, and scanning electron microscopy. More hydrophilic surfaces are created by modulating the PVA and TN concentrations in the blends. Disintegration tests showed that the films present durability in phosphate buffer (pH 7.4) and low stability in simulated gastric fluid (pH 1.2). The film created at 90/10 PVA/TN weight ratio and crosslinked at 109 PVA/glutaraldehyde molar ratio (sample PVA10/TN10) supports the attachment and proliferation of bone marrow mesenchymal stem cells after 7 days of culture. The scaffolding capacity of the PVA10/TN10 surface is compared with titanium, one of the most important biomedical materials used in bone replacements. Also, the PVA/TN films exhibited cytocompatibility, antioxidant and antimicrobial activity against Staphylococcus aureus and Pseudomonas aeruginosa. These properties make PVA/TN films are candidates for biomedical applications in the tissue engineering field., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Bacterial infections are a common mode of failure for medical implants. This study aims to develop antibacterial polyelectrolyte multilayer (PEM) coatings that contain a plant-derived condensed tannin polymer (Tanfloc, TAN) with inherent antimicrobial activity. Tanfloc is amphoteric, and herein we show that it can be used as either a polyanion or a polycation in PEMs, thereby expanding the possibility of its use in PEM coatings. PEMs are ordinarily formed using a polycation and a polyanion, in which the functional (ionic) groups of the two polymers are complexed to each other. However, using the amphoteric polymer Tanfloc with weakly basic amine and weakly acidic catechol and pyrogallol groups enables PEM formation using only one or the other of its functional groups, leaving the other functional group available to impart antibacterial activity. This work demonstrates Tanfloc-containing PEMs using multiple counter-polyelectrolytes including three polyanionic glycosaminoglycans of varying charge density, and the polycations N,N,N-trimethyl chitosan and polyethyleneimine. The layer-by-layer (LbL) assembly of PEMs was monitored using in situ Fourier-transform surface plasmon resonance (FT-SPR), confirming a stable LbL assembly. X-ray photoelectron spectroscopy (XPS) was used to evaluate surface chemistry, and atomic force microscopy (AFM) was used to determine the surface roughness. The LDH release levels from cells cultured on the Tanfloc-containing PEMs were not statistically different from those on the negative control (p > 0.05), confirming their non-cytotoxicity, while exhibiting remarkable antiadhesive and bactericidal properties against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus), respectively. The antibacterial effects were attributed to electrostatic interactions and Tanfloc's polyphenolic nature. This work underscores the potential of Tanfloc as a versatile biomaterial for combating infections on surfaces. [ABSTRACT FROM AUTHOR]

Poly(vinyl chloride) (PVC), a synthetic polymer, is used in various biomedical applications, particularly in the development of catheters. PVC-based catheters are engineered for blood-contacting applications. However, these materials lack antimicrobial properties, resulting in bacterial proliferation and subsequent infections. To overcome this disadvantage, blood-compatible and antimicrobial polyphenolic tannin-based surface coatings, known as polyelectrolyte multilayers (PEMs), were adsorbed onto PVC for the first time. PEMs were created on reduced PVC (Red-PVC) or oxidized PVC (Oxi-PVC) substrates using the layer-by-layer (LbL) approach. An amino-functionalized polyphenolic tannin derivative (TN-NH 2), commercially known as Tanfloc, and an unmodified polyphenolic tannin (TN), commercially known as Weibull black, were assembled (15 layers) on Oxi-PVC or Red-PVC at pH 5.0. PVC substrates and PEMs were characterized through atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA) measurements. The PEMs showed enhanced wettability compared to the unmodified PVC, with water contact angles ranging from 42° to 38°. The root mean square (R q) roughness of the PEMs ranged from 64.5 nm to 74.1 nm, while the unmodified PVC surface displayed a relatively smooth surface with a roughness of 5.4 nm. Stability tests demonstrated that the PEMs maintained their integrity in phosphate buffer (pH 7.4) over seven days at 37 ° C. The obtained PEMs were not toxic to human fibroblasts and human erythrocytes. The Live/Dead antimicrobial assay results indicated that the PEMs possessed biocidal activity against Pseudomonas aeruginosa (P. aeruginosa) and antiadhesive capacity toward Staphylococcus aureus (S. aureus) and P. aeruginosa after 24 h of incubation. Cytocompatible and antimicrobial tannin-based PEMs on modified PVC surfaces can represent a significant advancement in mitigating bacterial infections associated with PVC-based catheters. • Polyphenolic and amino-functionalized polyphenolic tannins were assembled on poly(vinyl chloride). • The surface coatings are cytocompatible toward fibroblast and red blood cells. • The surface coatings supported outstanding antiadhesive properties. • The surface coatings showed antimicrobial activity against Pseudomonas aeruginosa. • Surface coatings can mitigate bacterial infections associated with catheters. [ABSTRACT FROM AUTHOR]

• Surface coatings were engineered to treat bacterial corn streak disease. • The surface coatings protect the corn leaves from bacterial infection. • The surface coating reduces the synthon of bacterial corn streak dissemination. • A commercial ionic liquid has in vitro but not in vivo antimicrobial activity. • The filming-forming property of polymers is essential to protect the corn leaves. The bacterial corn streak disease, caused by Xanthomonas vasicola pv. vasculorum (Xvv) has emerged as a threat to corn production due to its rapid spread and resistance to conventional agrochemicals. Therefore, this study proposes polymeric surface coatings based on chitosan (CS) and tannins (TN) as antimicrobial agents against Xvv. The coatings were formed via the layer-by-layer (LbL) approach on oxidized polystyrene (PS). The coatings increased the wettability and roughness of the surfaces. In vitro assays measuring the minimum inhibitory and minimum bactericidal concentrations (MIC and MBC) demonstrated the antimicrobial activity of CS and TN. Coatings deposited on PS exhibited in vitro anti-adhesive properties against Xvv. The in vitro antimicrobial results were compared with control assays performed with an ionic liquid (IL). The IL was also associated with the polymeric coatings. Polymeric coatings, with or without IL, were deposited on corn leaves for in vivo assays. The IL had no activity against Xvv , and its presence in the CS solution seemed to impair the coating deposition on the corn leaves. However, the in vivo assays confirmed the protective efficacy of the polymeric coatings against Xvv infection, acting as physical barriers. The surface coatings also significantly reduced the Xvv symptoms in infected plants even after the disease spread. These outcomes were attributed to the film-forming ability of CS and TN polymers, the coatings' antimicrobial action, and the LbL efficiency in depositing the coatings on the corn leaves. This study introduces a promising environmentally and economically viable strategy for combating bacterial corn streak disease using biodegradable, cytocompatible natural polymers. The surface coatings offer a sustainable method to address bacterial corn disease, overcoming the limitations of agrochemicals. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new polymer-tannin adsorbet was created from the freezing-thawing method. • The acid black 172 and methylene blue were removed from aqueous solutions. • The adsorption was spontaneous and endothermic, being governed by physisorption. • Hydrophobic interactions are primarily responsible for dye removal. • Dye desorption quickly occurs in ethanol. This study presents an innovative adsorbent material obtained from the dialysis of an aqueous tannin derivative solution, followed by one freezing-thawing cycle at −4 °C. The freezing precipitated the tannin (459 ± 97 kDa) in water, yielding the solid adsorbent (d-TN) with aqueous insolubility and stability. The tannin derivative is mainly composed of amino-functionalized polyphenolic chains, but it comprises hydrolyzable tannins as well. The d-TN adsorbent removed the metal-complex acid black 172 (AcB) and methylene blue (MB) from water. Kinetic studies suggested that the nonlinear pseudo-first-order and pseudo-second-order models adjusted well to the experimental AcB and MB kinetic curves, respectively. Equilibrium studies indicated that the Sips model the experimental isotherms well, supporting maximum removal capacities (q m) of 119.1 mg/g for AcB and 310.2 mg/g for MB. The free Gibbs energy (ΔG0) was –3.33 kJ/mol for AcB adsorption and –4.16 kJ/mol for MB adsorption. The dye adsorption was spontaneous and endothermic, being governed by physisorption. Hydrophobic interactions are primarily responsible for dye removal. Therefore, dye desorption quickly occurs in ethanol. High-resolution XPS spectra characterized the d-TN surface after dye adsorption, confirming the adsorption of AcB composed of chromium ions (Cr3+). The eco-friendly d-TN can replace conventional adsorbents used to remove dyes from water. [ABSTRACT FROM AUTHOR]

• Polyelectrolyte multilayers based on a cationic condensed tannin are produced. • The cationic tannin derivative is blended with pectin and iota-carrageenan. • The polyelectrolyte multilayers prevent bacterial adhesion and biofilm formation. Bacterial adhesion and biofilm formation are significant issues associated with microbial infections in biomedical applications. It has been a challenge to prepare durable coatings with antiadhesive and antimicrobial activities. We show that a condensed tannin derivative (amino-functionalized) can be assembled with polysaccharides (pectin and iota -carrageenan) to create polyelectrolyte multilayers (PEMs). PEMs were prepared from the layer-by-layer approach by assembling polycationic-polyanionic pairs in an acetic acid-acetate buffer (pH 5.0). The tannin-based material (polycationic polymer) was characterized by X-ray photoelectron spectroscopy (XPS), while PEMs were characterized through XPS, in-situ Fourier transform surface plasmon resonance, atomic force microscopy, and water contact angle measurements. Compared to the native glass substrate, all PEMs present nanoscale surface roughness, and hydrophilic surfaces. A stability test performed in PBS for 7 days confirms that 15-layer PEMs are durable in aqueous environments. Initial adhesion and antimicrobial tests against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) show that the PEMs exhibit antiadhesive and bactericidal activities after 6 h. The antibacterial test in-vitro indicates that PEMs can kill and prevent the attachment and proliferation of bacteria significantly, especially during initial exposure. These PEMs can be applied as coatings to avoid infections imparted by microbial adhesion in biomedical applications. [ABSTRACT FROM AUTHOR]