Peptide-functionalized zirconia and new zirconia/titanium biocermets for dental applications

[Objective]: Titanium materials have been functionalized with biomolecules as a modern strategy to incorporate bioactive motifs that will expand and improve their biomedical applications. Here, we have biofunctionalized biomaterials based on zirconia of much interest for dentistry: the widely used bioceramic 3Y-TZP and a newly developed 3Y-TZP/Ti biocermet. [Methods]: The biosurfaces were activated, silanized, and functionalized with coatings made of oligopeptides. Surface activation by plasma or alkaline-etching was optimized. The surfaces were coated by tethering a purposely-designed RGD-containing peptide. We selected this oligopeptide as a model peptide to validate the effectiveness of the biofunctionalization process. Successful treatments after each step of the process were assessed by surface physical and chemical characterization with water contact angles and XPS, respectively. Coatings' stability was evaluated after 2 h sonication in water. Pre-osteoblasts adhesion on the functionalized surfaces was also studied. [Results]: 10-min air-plasma treatment effectively activated all types of materials with no detrimental effects on the material structure and hardness. Nitrogen XPS-peak confirmed that RGD-peptides were chemically-attached on the silanized samples. This was further confirmed by visualizing the functionalized surfaces with flourescence-labelled RGD-peptides before and after ultrasonication. Furthermore, RGD-functionalized surfaces significantly enhanced osteoblast adhesion on all types of substrates, which demonstrated their successful bioactivation. [Conclusions]: We successfully developed stable functional biocoatings on zirconia and biocermets made of oligopeptides. Surface bioactivation of zirconia-containing components for dental implant applications will enable their improved clinical performance by incorporating signalling oligopeptides to accelerate osseointegration, improving permucosal sealing, and/or incorporating antimicrobial properties to prevent peri-implant infections.This work was supported by the Office of the Vicepresident for Research at the University of Minnesota (Project #55466 of the Grant-in-Aid of Research, Artistry and Scholarship Program), the Spanish Ministry of Economy and Competitiveness (MINECO) under the project [MAT2012-38645]; the Spanish Ministry of Science and Innovation (MICINN) under the projects [MAT2009-14542-C02-02 and SAF2011-27863] and [CONSOLIDER CSD2009]; and the Government of the Principality of Asturias through PCTI. Parts of this work were carried out in the University of Minnesota I.T. Characterization Facility, which receives partial support from NSF through the MRSEC program.Peer Reviewe