title: In vivo evaluation of noble metal coatings.
abstract: A nanotopographic noble metal (Ag, Au, Pd) coating has been applied on commercial urinary catheters and used in more than 80,000 patients, with good clinical results. We have previously evaluated the biocompatibility of different variations of this coating, showing high cellular viability and function in vitro. However, the reasons for good clinical and preclinical behavior are not known. This in vivo study aimed to investigate the soft tissue peri-implant reaction to five coatings with systematically altered noble metal ratios after 1, 3, and 21 days of implantation in rats. The results show that coatings of silver only, or silver with medium amounts of gold and low-medium palladium content were superior to other tested coatings. Such surfaces were during the first days after implantation associated with a decreased recruitment of inflammatory cells to implant close exudates, a lower percentage of neutrophils, higher cell viability, and lower production of monocyte chemoattractant protein-1 (MCP-1), compared to the other coatings and uncoated silicone (PDMS) control. In contrast, the addition of higher concentrations of gold and palladium to silver induced a thicker soft tissue capsule. Coatings with high concentration of palladium induced the thickest fibrouscapsule after 21 days of implantation. The study demonstrates that by varying the noble metal ratio at implant surfaces it is possible to modulate inflammation and fibrosis in soft tissue.
authors.affiliation: Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Felicia
authors.initials: F
authors.lastname: Suska
authors.forename: Sara
authors.initials: S
authors.lastname: Svensson
authors.forename: Anna
authors.initials: A
authors.lastname: Johansson
authors.forename: Lena
authors.initials: L
authors.lastname: Emanuelsson
authors.forename: Helen
authors.initials: H
authors.lastname: Karlholm
authors.forename: Mattias
authors.initials: M
authors.lastname: Ohrlander
authors.forename: Peter
authors.initials: P
authors.lastname: Thomsen
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002470:Cell Survival; D018932:Chemokine CCL2 / Q000378:metabolism; D005260:Female; D008670:Metals; D018625:Microscopy, Atomic Force; D051381:Rats; D017207:Rats, Sprague-Dawley; D053773:Transforming Growth Factor beta1 / Q000378:metabolism
chemical_list: D001672:Biocompatible Materials; D018932:Chemokine CCL2; D008670:Metals; D053773:Transforming Growth Factor beta1