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Author: Schlosser, Michael ×

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    Gas-discharge plasma-assisted functionalization of titanium implant surfaces
    (Baech : Trans Tech Publications Ltd., 2010) Schröder, Karsten; Finke, Birgit; Polak, Martin; Lüthen, Frank; Nebe, Barbara; Rychly, Joachim; Bader, Rainer; Lukowski, Gerold; Walschus, Uwe; Schlosser, Michael; Ohl, Andreas; Weltmann, Klaus Dieter
    A crucial factor for in-growth of metallic implants in the bone stock is the rapid cellular acceptance whilst prevention of bacterial adhesion on the surface. Such contradictorily adhesion events could be triggered by surface properties. There already exists fundamental knowledge about the influence of physicochemical surface properties like roughness, titanium dioxide modifications, cleanness, and (mainly ceramic) coatings on cell and microbial behavior in vitro and in vivo. The titanium surface can be equipped with antimicrobial properties by plasma-based copper implantation, which allows the release and generation of small concentrations of copper ions during contact with water-based biological liquids. Additionally, the titanium surface was equipped with amino groups by the deposition of an ultrathin plasma polymer. This coating on the one hand does not significantly reduce the generation of copper ions, and on the other hand improves the adhesion and spreading of osteoblast cells. The process development was accompanied by physicochemical surface analyses like XPS, FTIR, contact angle, SEM, and AFM. Very thin modified layers were created, which are resistant to hydrolysis and delamination. These titanium surface functionalizations were found to have either an antimicrobial activity or cell-adhesive properties. Intramuscular implantation of titanium samples coated with the cell-adhesive plasma polymer in rats revealed a reduced inflammation reaction compared to uncoated titanium. © (2010) Trans Tech Publications.
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    Plasma polymerized allylamine-the unique cell-attractive nanolayer for dental implant materials
    (Basel : MDPI, 2019) Nebe, J. Barbara; Rebl, Henrike; Schlosser, Michael; Staehlke, Susanne; Gruening, Martina; Weltmann, Klaus-Dieter; Walschus, Uwe; Finke, Birgit
    Biomaterials should be bioactive in stimulating the surrounding tissue to accelerate the ingrowth of permanent implants. Chemical and topographical features of the biomaterial surface affect cell physiology at the interface. A frequently asked question is whether the chemistry or the topography dominates the cell-material interaction. Recently, we demonstrated that a plasma-chemical modification using allylamine as a precursor was able to boost not only cell attachment and cell migration, but also intracellular signaling in vital cells. This microwave plasma process generated a homogenous nanolayer with randomly distributed, positively charged amino groups. In contrast, the surface of the human osteoblast is negatively charged at −15 mV due to its hyaluronan coat. As a consequence, we assumed that positive charges at the material surface—provoking electrostatic interaction forces—are attractive for the first cell encounter. This plasma-chemical nanocoating can be used for several biomaterials in orthopedic and dental implantology like titanium, titanium alloys, calcium phosphate scaffolds, and polylactide fiber meshes produced by electrospinning. In this regard, we wanted to ascertain whether plasma polymerized allylamine (PPAAm) is also suitable for increasing the attractiveness of a ceramic surface for dental implants using Yttria-stabilized tetragonal zirconia.
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    Local Inflammatory Response after Intramuscularly Implantation of Anti-Adhesive Plasma-Fluorocarbon-Polymer Coated Ti6AI4V Discs in Rats
    (Basel : MDPI, 2021) Koppe, Charlotte; Hoene, Andreas; Walschus, Uwe; Finke, Birgit; Testrich, Holger; Pohl, Christopher; Brandt, Nico; Patrzyk, Maciej; Meichsner, Jürgen; Nebe, Barbara; Schlosser, Michael
    Orthopaedic implants and temporary osteosynthesis devices are commonly based on Titanium (Ti). For short-term devices, cell-material contact should be restricted for easy removal after bone healing. This could be achieved with anti-adhesive plasma-fluorocarbon-polymer (PFP) films created by low-temperature plasma processes. Two different PFP thin film deposition techniques, microwave (MW) and radiofrequency (RF) discharge plasma, were applied to receive smooth, hydrophobic surfaces with octafluoropropane (C3F8) or hexafluorohexane (C6F6) as precursors. This study aimed at examining the immunological local tissue reactions after simultaneous intramuscular implantation of four different Ti samples, designated as MW-C3F8, MW-C6F6, RF-C3F8 and Ti-controls, in rats. A differentiated morphometric evaluation of the inflammatory reaction was conducted by immunohistochemical staining of CD68+ macrophages, CD163+ macrophages, MHC class II-positive cells, T lymphocytes, CD25+ regulatory T lymphocytes, NK cells and nestin-positive cells in cryosections of surrounding peri-implant tissue. Tissue samples were obtained on days 7, 14 and 56 for investigating the acute and chronical inflammation (n = 8 rats/group). Implants with a radiofrequency discharge plasma (RF-C3F8) coating exhibited a favorable short- and long-term immune/inflammatory response comparable to Ti-controls. This was also demonstrated by the significant decrease in pro-inflammatory CD68+ macrophages, possibly downregulated by significantly increasing regulatory T lymphocytes.