Interactions of leukocytes and platelets with poly(lysine/leucine) immobilized on tetraethylene glycol-terminated self-assembled monolayers

Martins, M. Cristina L.; Ochoa-Mendes, Vanessa; Ferreira, Gisela; Barbosa, Judite N.; Curtin, Scott; Ratner, Buddy D.; Barbosa, Mário A.

doi:10.1016/j.actbio.2011.01.013

Cited by 9 publications

(6 citation statements)

References 35 publications

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“…As expected, the values obtained for the zeta potential are negative due to the influence of the gold support layer, being this described previously 33. The value for EG4‐SAMs is lower than the one obtained by Martins et al34 (−24 ± 0.9 mV), which can be explained by the different pH at which data was acquired (5.5), since this parameter affects the zeta potential 35. The three H. pylori strains used were also characterized according to their surface charge and wettability.…”

Section: Discussionsupporting

confidence: 85%

Effect of surface chemistry on bacterial adhesion, viability, and morphology

Parreira

Magalhães

Gonçalves

et al. 2011

J Biomedical Materials Res

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Helicobacter pylori (H. pylori) is one of the most common infectious agents in the world and it is thought to colonize the gastric mucosa of about half of the world's population causing several gastric diseases. In this work, the effect of surface chemistry on H. pylori nonspecific adhesion, viability, and morphology was evaluated using three H. pylori strains with different adhesins expression profile. Self-assembled monolayers (SAMs) of alkanethiols on gold were used to obtain surfaces exposing different functional groups: OH, CH3, and ethylene glycol (EG4). Bacterial adhesion onto the surfaces reached a plateau at 2 h. There was a correlation between adhesion and the exposed surface group, with bacterial cells adhering preferentially to CH3-SAMs while EG4-SAMs prevented H. pylori adhesion during the entire adhesion test (24 h). Surfaces that presented the EG4 group were also the only ones that significantly reduced the viability of adhered bacteria. Surface chemistry also influenced the morphology of adhered bacteria. The H. pylori rod shape observed in the control (Tissue Culture Polyethylene-TCPE) was only retrieved on CH3-SAMs. This work demonstrates that surface chemistry, namely specific functional groups on the material, influence the nonspecific adsorption of H. pylori. Moreover, the features of the bacterial strain and the surface chemistry can alter the adhesion kinetics, as well as the morphology and viability of attached bacteria.

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Section: Discussionsupporting

confidence: 85%

Effect of surface chemistry on bacterial adhesion, viability, and morphology

Parreira

Magalhães

Gonçalves

et al. 2011

J Biomedical Materials Res

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“…Additionally, the highly negative charge density of the PSBMA‐PAD@PDMS membrane surface could also induce a repulsive effect toward the negatively charged proteins and blood cells. [ 40 ]…”

Section: Resultsmentioning

confidence: 99%

Asymmetric Triple‐Functional Janus Membrane for Blood Oxygenation

Zhao,

Gao,

Chang

et al. 2023

Adv Healthcare Materials

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The oxygenation membrane, a core material of extracorporeal membrane oxygenation (ECMO), is facing challenges in balancing anti‐plasma leakage, gas exchange efficiency, and hemocompatibility. Here, inspired by the asymmetric structural features of alveolus pulmonalis, a novel triple‐functional membrane for blood oxygenation with a Janus architecture is proposed, which is composed of a hydrophobic polydimethylsiloxane (PDMS) layer to prevent plasma leakage, an ultrathin polyamide layer to enhance gas exchange efficiency with a CO2:O2 permeance ratio of ≈10.7, and a hydrophilic polyzwitterionic layer to improve the hemocompatibility. During the simulated ECMO process, the Janus oxygenation membrane exhibits excellent performance in terms of thrombus formation and plasma leakage prevention, as well as adequate O2 transfer rate (17.8 mL min−1 m−2) and CO2 transfer rate (70.1 mL min−1 m−2), in comparison to the reported oxygenation membranes. This work presents novel concepts for the advancement of oxygenation membranes and demonstrates the application potential of the asymmetric triple‐functional Janus oxygenation membrane in ECMO.

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“…The zeta potential of both unmodified and modified chitosan films was determined using an ElectroKinetic Analyzer (Anton Paar GmbH, Graz, Austria) with a stamp cell suitable for flat substrates, based on the streaming potential method, as previously described by us [ 32 , 33 ]. Briefly, the stamp cell has two poly(methyl methacrylate) (PMMA) sample holders with a cross-section of 1 × 2 cm.…”

Section: Methodsmentioning

confidence: 99%

Influence of Immobilization Strategies on the Antibacterial Properties of Antimicrobial Peptide-Chitosan Coatings

et al. 2023

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It is key to fight bacterial adhesion to prevent biofilm establishment on biomaterials. Surface immobilization of antimicrobial peptides (AMP) is a promising strategy to avoid bacterial colonization. This work aimed to investigate whether the direct surface immobilization of Dhvar5, an AMP with head-to-tail amphipathicity, would improve the antimicrobial activity of chitosan ultrathin coatings. The peptide was grafted by copper-catalyzed azide-alkyne cycloaddition (CuAAC) chemistry by either its C- or N- terminus to assess the influence of peptide orientation on surface properties and antimicrobial activity. These features were compared with those of coatings fabricated using previously described Dhvar5-chitosan conjugates (immobilized in bulk). The peptide was chemoselectively immobilized onto the coating by both termini. Moreover, the covalent immobilization of Dhvar5 by either terminus enhanced the antimicrobial effect of the chitosan coating by decreasing colonization by both Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. Relevantly, the antimicrobial performance of the surface on Gram-positive bacteria depended on how Dhvar5-chitosan coatings were produced. An antiadhesive effect was observed when the peptide was grafted onto prefabricated chitosan coatings (film), and a bactericidal effect was exhibited when coatings were prepared from Dhvar5-chitosan conjugates (bulk). This antiadhesive effect was not due to changes in surface wettability or protein adsorption but rather depended on variations in peptide concentration, exposure, and surface roughness. Results reported in this study show that the antibacterial potency and effect of immobilized AMP vary greatly with the immobilization procedure. Overall, independently of the fabrication protocol and mechanism of action, Dhvar5-chitosan coatings are a promising strategy for the development of antimicrobial medical devices, either as an antiadhesive or contact-killing surface.

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Interactions of leukocytes and platelets with poly(lysine/leucine) immobilized on tetraethylene glycol-terminated self-assembled monolayers

Cited by 9 publications

References 35 publications

Effect of surface chemistry on bacterial adhesion, viability, and morphology

Effect of surface chemistry on bacterial adhesion, viability, and morphology

Asymmetric Triple‐Functional Janus Membrane for Blood Oxygenation

Influence of Immobilization Strategies on the Antibacterial Properties of Antimicrobial Peptide-Chitosan Coatings

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