title: Novel microcalorimetric assay for antibacterial activity of implant coatings: The cases of silver-doped hydroxyapatite and calcium hydroxide.
abstract: Biomaterials with antimicrobial properties are now commonly used in different clinical specialties including orthopedics, endodontic, and traumatology. As a result, assessing the antimicrobial effect of coatings applied on implants is of critical importance. In this study, we demonstrate that isothermal microcalorimetry (IMC) can be used for monitoring bacterial growth and biofilm formation at the surface of such coatings and for determining their antimicrobial effects. The antibacterial effects of silver doped hydroxyapatite (HA) and calcium hydroxide coatings on Staphylococcus epidermidis were determined with a minimal workload. Using the Gompertz growth model we determined biofilm growth rates close to those values reported in the literature. Furthermore, we were able to estimate the reduction in the bacterial inocula originally applied at the surface of the coatings. Therefore, in addition to monitoring the antimicrobial effect of silver doped HA and calcium hydroxide coatings, we also demonstrate that IMC might be a valuable tool for assessing such antimicrobial properties of implant coatings at a minimal workload.
authors.affiliation: Department of Urology, University Hospital Basel, CH-4031, Basel, Switzerland.|Laboratory for Biomechanics and Biocalorimetry, Biozentrum - Pharmazentrum, University of Basel, CH-4056, Basel, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Braissant
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Chavanne
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: de Wild
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland.
authors.forename: Uwe
authors.initials: U
authors.lastname: Pieles
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Stevanovic
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland.
authors.forename: Ralf
authors.initials: R
authors.lastname: Schumacher
authors.affiliation: University of Applied Sciences and Arts Northwestern Switzerland (FHNW), School of Life Sciences, CH-4132, Muttenz, Switzerland.
authors.forename: Lukas
authors.initials: L
authors.lastname: Straumann
authors.affiliation: Laboratory for Biomechanics and Biocalorimetry, Biozentrum - Pharmazentrum, University of Basel, CH-4056, Basel, Switzerland.|Orthomerian, Gotthelfstrasse 105, 4054, Basel, Switzerland.
authors.forename: Dieter
authors.initials: D
authors.lastname: Wirz
authors.affiliation: Medicoat AG, Almuesenacherstrasse 2a, CH-5506, Mägenwil, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Gruner
authors.affiliation: Department of Urology, University Hospital Basel, CH-4031, Basel, Switzerland.|Laboratory for Biomechanics and Biocalorimetry, Biozentrum - Pharmazentrum, University of Basel, CH-4056, Basel, Switzerland.
authors.forename: Alexander
authors.initials: A
authors.lastname: Bachmann
authors.affiliation: Department of Urology, University Hospital Basel, CH-4031, Basel, Switzerland.|Laboratory for Biomechanics and Biocalorimetry, Biozentrum - Pharmazentrum, University of Basel, CH-4056, Basel, Switzerland.
authors.forename: Gernot
authors.initials: G
authors.lastname: Bonkat
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology; D002126:Calcium Hydroxide / Q000737:chemistry / Q000494:pharmacology; D002151:Calorimetry / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology; D019736:Prostheses and Implants / Q000382:microbiology*; D012834:Silver / Q000737:chemistry / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D012834:Silver; D017886:Durapatite; D002126:Calcium Hydroxide
keywords: Staphylococcus; antibacterial implant coatings; calcium hydroxide; hydroxyapatite; isothermal microcalorimetry