Details

Autor(en) / Beteiligte

• Vaz, Juliana M.
• Taketa, Thiago B.
• Hernandez-Montelongo, Jacobo
• Chevallier, Pascale
• Cotta, Monica A.
• Mantovani, Diego
• Beppu, Marisa M.

Titel

Antibacterial properties of chitosan-based coatings are affected by spacer-length and molecular weight

Ist Teil von

• Applied surface science, 2018-07, Vol.445, p.478-487

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2018

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •An antibacterial chitosan coating using plasma-grafting techniques was developed.•It is a versatile, eco-friendly, and simple strategy to inhibit pathogenic bacteria.•Antibacterial chitosan-based coating was covalently linked to the substrate.•Number of terminal groups of the spacers influences the coating properties.•Amount and availability of chitosan NH2 groups affect the antibacterial behavior. Chitosan is a biopolymer with antibacterial properties, which are dependent on its molecular weight (Mw) and its degree of deacetylation (DDA). When grafted on surfaces as a coating, chitosan antibacterial efficiency is also dependent on the polymer chain conformation on the surface, as the amine groups, responsible of the antibacterial effect, should be available for contact with bacteria. To investigate this behavior, chitosans with different Mw were grafted onto plasma aminated surfaces through three different spacers: glutaric anhydride (GA), poly(ethylene–glycol) bis(carboxymethyl) ether (PEGb), and poly(ethylene-alt-maleic anhydride) (PA). The grafting efficiency was evaluated by X-ray Photoelectron Spectroscopy (XPS), contact angle and Rose Bengal test, while morphological features were assessed by profilometry analyses. Results evidenced a clear influence of the anchor arm length and of the Mw of chitosan both on the grafting efficiency and on the antibacterial behavior. PA CHIMW surface exhibited a better antibacterial response compared to GA and PEGb, which could be correlated to a denser coating coverage as seen by XPS and profilometry results. Further, PA CHIMW coating displayed a higher amine density, thus promoting the interaction with the bacteria cell wall. Based on these results, chitosan-based coatings can then be extended to a wide range of antibacterial applications.