Antimicrobial activity of commercial calcium phosphate based materials functionalized with vanillin

[EN] Infections represent one of the most frequent causes of arthroplasty revision. Thus, design of new antimi-crobial scaffolds to reduce implant rejections, bone infections and associated medical costs is highlydesired. In recent years, essential oil components (EOCs) have merged as compounds with signi¿cantantimicrobial activity that can be attached to speci¿c surfaces to enhance and prolong their antimicrobialeffect. Herein calcium phosphate CaP regenerative materials have been coated with a vanillin derivativeto combine its original bone regeneration properties with antimicrobial action of EOCs. Materials in formof microparticles and blocks were prepared and fully characterized. Clonogenic viability tests demon-strated that low concentrations of material (10 mg/mL-1) resulted effective to kill 100% of E. coli DH5abacteria. Additionally, vanillin containing scaffolds did not display any toxic effect over cells, yet theypreserve the ability to express alkaline phosphatase (ALPL), collagen type 1, chaina1(COL1A1) and bonegamma-carboxyglutamic acid-containing protein or osteocalcin (BGLAP), which are genes typicallyexpressed by osteoblasts. These results demonstrate that commercially available scaffolds can be func-tionalized with EOCs, achieving antimicrobial activity and open up a new approach for the treatmentand prevention of infection.
The authors thank the Spanish Government, Spain for projects MAT2015-64139-C04-01-R (MINECO/FEDER). Also, Generalitat Valenciana, Spain (project PROMETEOII/2014/047) is acknowledged for their support. L. P. thanks Universitat Politecnica de Valencia, Spain for her FPI and mobility grants. B.D. thanks to Ministerio de Economia, Ciencia y Competitividad, Spain for his Juan de la Cierva-Formation fellowship. The authors also thank the Electron Microscopy Service at the UPV for their support. The authors are grateful to IRCCS Rizzoli Orthopaedic Institute, Italy (funds 5 X 1000 year 2015, cod. 6879).