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Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/12328

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Institute: search.filters.UBSInstitut.Fakultätsübergreifend / Sonstige EinrichtungInstitute: search.filters.UBSInstitut.Institut für Keramische Materialien und Technologien

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    ItemOpen Access
    Biodegradable, antibacterial TCP implant coatings with magnesium phosphate‐based supraparticles
    (2025) Lanzino, Maria Carolina; Höppel, Anika; Le, Long‐Quan R. V.; Morelli, Stefania; Killinger, Andreas; Rheinheimer, Wolfgang; Mayr, Hermann O.; Dembski, Sofia; Al‐Ahmad, Ali; Mayr, Moritz F.; Gbureck, Uwe; Seidenstuecker, Michael
    This work highlights the potential of porous, bioactive coatings to advance implant technology and address critical clinical challenges. A key issue in implant coatings is to achieve the balance between infection prevention and successful osseointegration. Although titanium implants are widely used due to their mechanical strength and biocompatibility, their bioinert nature limits integration with bone tissue. To address these issues, porous calcium phosphate (CaP) coatings have been developed to enhance cell attachment and bone growth. However, CaP, especially in the widely used form of hydroxyapatite (HAp), has a low resorption rate, which often leads to prolonged coating stability and impairs natural bone remodeling. To overcome this limitation, magnesium phosphate (MgP), an underexplored but promising biomaterial with high biocompatibility and osteogenic potential, can be introduced. Another innovative strategy is the doping of biomaterials with antibacterial ions, among which copper (Cu) has attracted particular attention. The incorporation of Cu into the coating matrix can significantly reduce the risk of post‐operative infection while promoting angiogenesis, a key factor for rapid and stable implant integration. This study presents bone implant coatings composed of tricalcium phosphate (TCP) and Cu‐doped MgP clustered nanoparticles (supraparticles) fabricated via high‐velocity suspension flame spraying (HVSFS). This particle system addresses current challenges in bone tissue regeneration by synergistically combining the high biodegradability of MgP, the bone‐mimicking properties of CaP, and the antibacterial capabilities of Cu. In addition, the HVSFS process enables the creation of thin layers with porous microstructures. Biocompatibility of the prepared coatings was assessed using MG63 osteosarcoma cells, while the antibacterial efficacy was tested against Staphylococcus aureus and Escherichia coli . The incorporation of Cu‐doped MgP supraparticles (MgPCu and MgPCu HT) into TCP coatings resulted in high Cu release and pronounced antibacterial efficacy compared to the TCP reference, while the addition of Cu‐doped FT supraparticles (FTCu) led to high cell proliferation.
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    ItemOpen Access
    Controlling grain boundary segregation to tune the conductivity of ceramic proton conductors
    (2024) Kindelmann, Moritz; Povstugar, Ivan; Kuffer, Severin; Jennings, Dylan; Ebert, Julian N.; Weber, Moritz Lukas; Zahler, Pascal; Escolastico, Sonia; Almar, Laura; Serra, Jose M.; Kaghazchi, Payam; Bram, Martin; Rheinheimer, Wolfgang; Mayer, Joachim; Guillon, Olivier
    Acceptor‐doped barium zirconates are of major interest as proton‐conducting ceramics for electrochemical applications at intermediate operating temperatures. However, the proton transport through polycrystalline microstructures is hindered by the presence of a positive space charge potential at grain boundaries. During high‐temperature sintering, the positive charge acts as a driving force for acceptor dopant segregation to the grain boundary. Acceptor segregation to grain boundaries has been observed in sintered ceramics, but the fundamental relationship between the segregation kinetics and the protonic conductivity is poorly understood. Here, a comprehensive study of the influence of acceptor dopant segregation on the electrochemical properties of grain boundaries in barium zirconate ceramics is presented. An out‐of‐equilibrium model material that displays no detectable Y segregation at its grain boundaries is explicitly designed. This model material serves as a starting point to measure the kinetics of segregation and the induced changes in grain boundary conductivity upon varying thermal histories. Furthermore, the electrochemical results from impedance spectroscopy to atomic resolution transmission electron microscopy, atom probe tomography, and DFT simulations are correlated. It is discovered that acceptor dopant segregation drastically increases the proton conductivity in both the model system and several other application‐relevant compositions.