Multifunctional coatings based on copper-doped bioactive glass/gelatin using sol-gel technique for stainless steel 316 L implant

Abstract Improveming of metal implant surfaces with multifunctional coatings to increase their biocompatibility and antibacterial activity is considered a critical issue for orthopedic surgeons. In this study, antibacterial hybrid coatings based on bioactive glass contained copper with different percentages (0, 5, and 10 mol %, corresponding to BG0/Gel, BG5/Gel, and BG10/Gel, sample codes, respectively) and gelatin for coating stainless steel 316 L (SS 316 L) using the ambient temperature sol-gel spin coating method. Moreover, the coatings were in situ loaded with the antibacterial gentamicin drug. FTIR, Raman, SEM-EDX, adhesion strength, and contact angle were measured. Furthermore, biodegradation was conducted in the simulated body fluid (SBF). Also, electrochemical corrosion behavior was determined for the coated metal substrates. Finally, the cell viability and antibacterial activity of the hybrid coatings were tested. The results show that the formed coatings were homogeneous with a thickness range of 13–21 μm. The adhesion strength was 0.27, 0.15, and 0.23 MPa, as well as the contact angle was 80⁰, 68⁰, and 70⁰, for BG0/Gel, BG5/Gel, and BG10/Gel, respectively. In addition, all coatings showed excellent cell biocompatibility and antibacterial activity; specifically, those containing drugs possessed an antibacterial effect. Finally, the coating improved clearly the corrosion resistance of metal substrates. Taken as a whole, the results recommended that the prepared coatings can potentially be used in orthopedic applications.