| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 609485 | Journal of Colloid and Interface Science | 2010 | 6 Pages |
The adsorption and elution of the antimicrobial peptide nisin at silanized silica surfaces coated to present pendant polyethylene oxide chains was detected in situ by zeta potential measurements. Silica microspheres were treated with trichlorovinylsilane to introduce hydrophobic vinyl groups, followed by self assembly of the polyethylene oxide–polypropylene oxide–polyethylene oxide (PEO–PPO–PEO) triblock surfactant Pluronic® F108, or an F108 derivative with nitrilotriacetic acid end groups. Triblock-coated microspheres were γ-irradiated to covalently stabilize the PPO-surface association. PEO layer stability was evaluated by triblock resistance to elution by SDS, and layer uniformity was evaluated by fibrinogen repulsion. Introduction of nisin to uncoated or triblock-coated microspheres produced a significant positive change in surface charge (zeta potential) as a result of adsorption of the cationic peptide. In sequential adsorption experiments, the introduction of fibrinogen to nisin-loaded triblock layers caused a decrease in zeta potential that was consistent with partial elution of nisin and/or preferential location of fibrinogen at the interface. This change was substantially more pronounced for uncoated than triblock-coated silica, indicating that the PEO layer offers enhanced resistance to nisin elution.
Graphical abstractA layer of pendant PEO loaded with nisin (top). Contact with fibrinogen is accompanied by partial elution and reestablishment of any lost steric repulsive capacity (bottom).Figure optionsDownload full-size imageDownload high-quality image (45 K)Download as PowerPoint slideResearch highlights► Nisin entrapment occurs within fibrinogen repellent, pendant PEO layers. ► Entrapment within PEO enhances nisin resistance to elution. ► Sequential adsorption results suggest retention of PEO steric repulsive character.
