Effect of Dielectric Properties of Ceramic-Solvent Interface on the Binding of Protein to Oxide Ceramics: a Non Local Electrostatic Approach

TL;DR

This study uses a non-local electrostatic model to show how the dielectric properties of ceramic- solvent interfaces influence protein binding to oxide ceramics, revealing that moderate dielectric constants enhance electrostatic attraction.

Contribution

It introduces a non-local electrostatic approach to analyze how dielectric properties affect protein-ceramic binding, highlighting the importance of interfacial solvent layers.

Findings

Electrostatic energy depends non-monotonically on ceramic dielectric constant.

Moderate dielectric ceramics (below ~35) enhance protein attraction.

Reduced dielectric ceramics can strengthen protein-implant binding.

Abstract

The contribution of electrostatic interactions to the free energy of binding between model protein and a ceramic implant surface in the aqueous solvent, considered in the framework of the non-local electrostatic model, is calculated as a function of the implant low-frequency dielectric constant. We show that the existence of a dynamically ordered (low-dielectric) interfacial solvent layer at the protein-solvent and ceramic-solvent interface markedly increases charging energy of the protein and ceramic implant, and consequently makes the electrostatic contribution to the protein-ceramic binding energy more favorable (attractive). Our analysis shows that the corresponding electrostatic energy between protein and oxide ceramics depends non-monotonically on the dielectric constant of ceramic. Obtained results indicate that protein can attract electrostatically to the surface if ceramic material has a moderate dielectric constant below or about 35 (in particularly ZrO2 or Ta2O5). This is in contrast to classical (local) consideration of the solvent, which demonstrates an unfavorable electrostatic interaction of protein with typical metal oxide ceramic materials (dielectric constant>10). Thus, a solid implant coated by combining oxide ceramic with a reduced dielectric constant can be beneficial to strengthen the electrostatic binding of the protein-implant complex.