Interaction of lignin-derived dimer and eugenol-functionalized silica nanoparticles with supported lipid bilayers.

The potential to impart surfaces with specific lignin-like properties (i.e. resistance to microbes) remains relatively unexplored due to the lack of well-defined lignin-derived small molecules and corresponding surface functionalization strategies. Here, allyl-modified guaiacyl β-O-4 eugenol (G-eug) lignin-derived dimer is synthesized and attached to mesoporous silica nanoparticles (MSNPs) via click chemistry. The ability of G-eug lignin-dimer functionalized particles to interact with and disrupt synthetic lipid bilayers is compared to that of eugenol, a known natural antimicrobial. Spherical MSNPs (∼150 nm diameter with 4.5 nm pores) were synthesized using surfactant templating. Post-synthesis thiol (SH) attachment was performed using (3-mercaptopropyl) trimethoxysilane and quantified by Ellman's test. The resultant SH-MSNPs were conjugated with the G-eug dimers or eugenol by a thiol-ene reaction under ultraviolet light in the presence of a photo initiator. From thermogravimetric analysis (TGA), attachment densities of approximately 0.22 mmol eugenol/g particle and 0.13 mmol G-eug dimer/g particle were achieved. The interaction of the functionalized MSNPs with a phospholipid bilayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (representing model cell membranes) supported on gold surface was measured using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D). Eugenol-grafted MSNPs in PBS (up to 1 mg/mL) associated with the bilayer and increased the mass adsorbed on the QCM-D sensor. In contrast, MSNPs functionalized with G-eug dimer show qualitatively different behavior, with more uptake and evidence of bilayer disruption at and above a particle concentration of 0.5 mg/mL. These results suggest that bio-inspired materials with conjugated lignin-derived small molecules can serve as a platform for novel antimicrobial coatings and therapeutic carriers.

Informations de copyright

Copyright © 2020 Elsevier B.V. All rights reserved.

Déclaration de conflit d'intérêts

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.