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Abstract: Medical implant-associated infections resulting from biofilm formation triggered by unspecific protein adsorption arethe prevailing cause of implant failure. However, implant surfaces rendered with multifunctional bioactive nanocoatings offer apromising alternative to prevent the initial attachment of bacteria and effectively interrupt biofilm formation. The need to researchand develop novel and stable bioactive nanocoatings for medical implants and a comprehensive understanding of their properties incontact with the complex biological environment are crucial. In this study, we developed an aqueous stable and crosslinker-freepolyelectrolyte−surfactant complex (PESC) composed of a renewable cationic polysaccharide, chitosan, a lysine-based anionicsurfactant (77KS), and an amphoteric antibiotic, amoxicillin, which is widely used to treat a number of infections caused by bacteria.We successfully introduced the PESC as bioactive functional nanolayers on the“model”and“real”polydimethylsiloxane (PDMS)surfaces under dynamic and ambient conditions. Besides their high stability and improved wettability, these uniformly depositednanolayers (thickness: 44−61 nm) with mixed charges exhibited strong repulsion toward three model blood proteins (serumalbumin,fibrinogen, andγ-globulin) and their competitive interactions in the mixture in real-time, as demonstrated using a quartzcrystal microbalance with dissipation (QCM-D). The functional nanolayers with a maximum negative zeta potential (ζ:−19 to−30mV at pH 7.4), water content (1628−1810 ng cm−2), and hydration (low viscosity and elastic shear modulus) correlated with themass, conformation, and interaction nature of proteins. In vitro antimicrobial activity testing under dynamic conditions showed thatthe charged nanolayers actively inhibited the growth of both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcusaureus) bacteria compared to unmodified PDMS. Given the ease of fabrication of multifunctional and charged biobased coatingswith simultaneous protein-repellent and antimicrobial activities, the limitations of individual approaches could be overcome leadingto a better and advanced design of various medical devices (e.g., catheters, prosthetics, and stents).
Keywords: silicone implants, protein-repellent, antimicrobial, chitosan, lysine, bioactive coatings, adsorption, QCM-D
Published in DKUM: 15.04.2024; Views: 266; Downloads: 20
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Abstract: The use of therapeutic agents that inhibit bone resorption is crucial to prolong implant life, delay revision surgery, and reduce the burden on the healthcare system. These therapeutic agents include bisphosphonates, various nucleic acids, statins, proteins, and protein complexes. Their use in systemic treatment has several drawbacks, such as side effects and insufficient efficacy in terms of concentration, which can be eliminated by local treatment. This review focuses on the incorporation of osteoclast inhibitors (antiresorptive agents) into bioactive coatings for bone implants. The ability of bioactive coatings as systems for local delivery of antiresorptive agents to achieve optimal loading of the bioactive coating and its release is described in detail. Various parameters such as the suitable concentrations, release times, and the effects of the antiresorptive agents on nearby cells or bone tissue are discussed. However, further research is needed to support the optimization of the implant, as this will enable subsequent personalized design of the coating in terms of the design and selection of the coating material, the choice of an antiresorptive agent and its amount in the coating. In addition, therapeutic agents that have not yet been incorporated into bioactive coatings but appear promising are also mentioned. From this work, it can be concluded that therapeutic agents contribute to the biocompatibility of the bioactive coating by enhancing its beneficial properties.
Keywords: bioactive coatings, implants, bone resorption, osteolysis, osteoclats inhibitors
Published in DKUM: 17.08.2023; Views: 356; Downloads: 54
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