EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Biomedical coatings exhibiting antibacterial properties are receiving increasing attention to enhance the surface properties of metallic implants. The current study focuses on the fabrication and characterization of copper(II) – chitosan (Cu(II)-CS) – strontium doped bioactive glass (SrBG) composite coatings on stainless steel substrates via electrophoretic deposition (EPD). Initially, Cu(II)-CS complexes and 5 mol % SrBG were synthesized by in-situ precipitation and sol-gel method, respectively. The EPD suspension was prepared by dissolving complexes in 20 % (v/v) distilled water and 1% (v/v) acetic acid solution by magnetic stirring. After complete dissolution of complexes, 0.5 mg/mL of SrBG and pure ethanol 79% (v/v) were added to the solution. EPD was performed by DC – EPD at 15 V for 5 minutes at room temperature by keeping the inter-electrode distance at 10 mm. The successful deposition of coatings on stainless steel was confirmed by physicochemical characterization methods. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy were carried out in terms of morphological and elemental analysis, which confirmed the uniform distribution of Cu(II) as well as SrBG in the CS matrix. Thermogravimetric analysis (TGA) was used to determine the weight percent of CS and SrBG in composite coatings. The amount of Cu(II)-CS and SrBG in coatings were correlated with their relative concentrations in EPD suspension. Furthermore, wettability and enzymatic degradation of the composite coatings were affected by the concentration of Cu(II) ions in the CS matrix. Composite coatings showed remarkable antibacterial activity against both Gram-positive and −negative bacteria. Cell viability tests on coatings after 24 h confirm their lack of cytotoxicity to human osteoblast-like cells up to a certain threshold concentration of Cu(II). Such antibiotic-free and antibacterial coatings are potential candidates for biomedical implants.