Antibacterial Film Formation through Iron(III) Complexation and Oxidation-Induced Cross-Linking of OEG-DOPA

Abstract

Catechols are prone to oxidative polymerization as well as complex formation with metal ions. These two features of catechols have played an important role in the construction of functional films on various surfaces. For example, marine antifouling films and antibacterial films were successfully prepared by oxidative polymerization and metal complexation of catechol-containing molecules, respectively. However, the effect of simultaneous metal complexation and oxidative polymerization on functional film formation has not yet been fully investigated. Herein, as a derivative of 3-(3,4dihydroxyphenyl)-L-alanine (DOPA), we synthesized an ethylene glycol-derivatized DOPA (OEG-DOPA) and formed OEG-DOPA thin films based on (1) oxidative polymerization and (2) the complexation between catechol groups of OEG-DOPA and iron(III) (Fe III ) ions. Either or both approaches were used for the film formation. OEG-DOPA film formation was characterized by ellipsometry, contact angle goniometry, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy. Among the conditions used, the formation of a uniform film was only achieved with the dual cross-linking system of Fe III complexation and oxidation-induced covalent bond formation. Compared to the uncoated substrate and other OEG-DOPA films prepared under different conditions, the uniform OEG-DOPA film strongly inhibited bacterial adhesion, showing excellent antibacterial capability. We think that our surface-coating strategy can be applied to medical devices, tools, and implants where bacterial adhesion and biofilm formation should be prevented. This work can also serve as a basis for the construction of functional thin films for other catechol-functionalized materials.

Zwitterionic Polydopamine/Protein G Coating for Antibody Immobilization: Toward Suppression of Nonspecific Binding in Immunoassays

“…It is well known that dopamine and DOPA derivatives, including ZW -DOPA, can coat various substrates under oxidation conditions. ,, Moreover, the molecules codissolved with ZW -DOPA can also be coated onto the substrates during incubation. ,,, Therefore, ZW -DOPA/protein G-coated substrates can be obtained after the simple incubation of bare substrates in the ZW -DOPA/protein G solution, as shown in Figure . Protein G is an antibody-binding protein that can target the Fc region of an antibody. , Hence, the antibody can be routinely immobilized onto the ZW -DOPA/protein G-coated substrate.…”

“…It is well known that dopamine and DOPA derivatives, including ZW-DOPA, can coat various substrates under oxidation conditions. 18,21,22 Moreover, the molecules codissolved with ZW-DOPA can also be coated onto the substrates during incubation. 14,22,27,28 Therefore, ZW-DOPA/protein Gcoated substrates can be obtained after the simple incubation of bare substrates in the ZW-DOPA/protein G solution, as shown in Figure 1.…”

Material priority engineered metal-polyphenol networks: mechanism and platform for multifunctionalities

“…To address the issue of infections, effective antibacterial materials are still highly sought. Since both polyphenols [ 31 , 52 – 54 ] and iron [ 55 , 56 ] have the ability to kill bacteria, we next tested the antibacterial properties of the coating. The ability of the PC-MPN coating to kill bacteria was tested by immersing the coating into bacterial solutions and then comparing the deformed and collapsed bacteria to those on the silicon wafer control.…”

Material Priority Engineered Metal-Polyphenol Networks: Mechanism And Platform For Multifunctionalities

“…To address the issue of infections, effective antibacterial materials are still highly sought. Since both polyphenols [31,[48][49][50] and iron [51,52] have the ability to kill bacteria, we next tested the antibacterial properties of the coating. The ability of the PC-MPN coating to kill bacteria was tested by immersing the coating into bacterial solutions and then comparing the deformed and collapsed bacteria to those on the silicon wafer control.…”