Material Science Smart Coatings

[摘要] 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 nonlocal 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 nonmonotonically on the dielectric constant of ceramic, ??_C. Obtained results indicate that protein can attract electrostatically to the surface if ceramic material has a moderate ??_C 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 (??_C>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.

[发布日期] 2014-07-01

[学科分类] 材料科学（综合）

[关键词] non-local electrostatics;solvent permittivity;interfacial water;ceramic implants;protein adsorption;biocompatibility