title: Site-specific gene expression analysis of implant-near cells in a soft tissue infection model - Application of laser microdissection to study biomaterial-associated infection.
abstract: Analysis of the implant-tissue interface is important for an understanding of the cellular response to biomaterials with different surface characteristics. However, inaccessibility to the site has restricted the detailed evaluation of the tissue surrounding the implant. Laser microdissection enables the isolation of specific cells and tissues for subsequent DNA, RNA, or protein analysis. The present experimental study employed laser microdissection to analyze tissue-specific differences in gene expression in cells around infected or control titanium implants 72 h after subcutaneous implantation in a rat model. Three different tissue zones located 0-800 μm away from the implant-tissue interface were analyzed. Implant sites challenged with a dose of 106CFU Staphylococcus epidermidis demonstrated higher gene expression of selected markers for inflammation (TNF-α, IL-6), cell recruitment (MCP-1, IL-8, IL-8 R), infection (TLR2), and tissue remodeling (MMP-9) compared with control implants. Furthermore, the gene expression analysis of the three extracted tissue zones revealed marked spatial differences, depending on the distance to the implant. Control implants continuously induced higher cell gene expression in the implant-tissue interface compared with cells 200-800 μm away from the implant, whereas the sites inoculated with S. epidermidis resulted in high gene expression further away from the implant as well. In conclusion, this study demonstrates that laser microdissection is an interesting tool, revealing both gene- and site-specific gene expression patterns in the implant-tissue interface. The technique provides an opportunity for detailed molecular dissection of the biological events related to the implant but occurring at different distances from the implant. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2210-2217, 2017.
authors.affiliation: Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Svensson
authors.affiliation: Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden.
authors.forename: Margarita
authors.initials: M
authors.lastname: Trobos
authors.affiliation: Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden.
authors.forename: Omar
authors.initials: O
authors.lastname: Omar
authors.affiliation: Department of Biomaterials, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.|BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Gothenburg, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Thomsen
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000009:adverse effects*; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D061346:Laser Capture Microdissection / Q000379:methods; D019736:Prostheses and Implants / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018461:Soft Tissue Infections / Q000209:etiology* / Q000235:genetics* / Q000473:pathology; D013203:Staphylococcal Infections / Q000209:etiology* / Q000235:genetics* / Q000473:pathology; D013212:Staphylococcus epidermidis / Q000302:isolation & purification; D014025:Titanium / Q000009:adverse effects*
chemical_list: D001672:Biocompatible Materials; D014025:Titanium
keywords: chemotaxis; gene expression; in vivo; infection; laser microdissection