Electrophoretic deposition of chitosan/mesoporous bioactive glass nanoparticles/ hexagonal boron nitride composite coating on AZ31 Mg alloy for maxillofacial and biomedical applications

Magnesium-based biodegradable implants are an excellent choice for biomedical applications including maxilofacial and orthopedic applications due to their elastic modulus which closely matches that of the bone. However, their uncontrolled degradation rate in human physiological fluids is a critical problem that leads to premature failure of the implant. This problem can be resolved by depositing a composite coating of chitosan/ mesoporous bioactive glass nanoparticles (MBGNs) / hexagonal boron nitride (hBN) on AZ31 Mg alloy. The composite coating was deposited at optimized parameters (applied potential of 15 V for 7 min) on AZ31. The composite coating was subjected to various characterizations to evaluate the required properties of the modified surface of AZ31 for orthopedic applications. Scanning electron microscopy (SEM) revealed the uniform morphology of the composite coating with a thickness of 103 ± 3. The presence of agglomerates of MBGNs/hBN was observed in the chitosan matrix of composite coating at the higher magnification. Furthermore, the Fourier transform infrared (FTIR) spectroscopy also confirmed the functional groups of the composite coating. Surface analysis showed that the composite coating exhibited an average surface roughness of 1.25 ± 0.05 µm with a slight hydrophilic nature by showing a contact angle of 73 ± 2°. Biological studies confirm that the composite coating exhibits cytocompatibility and has potential for bone regeneration. An electrochemical analysis supported by a Nyquist plot of Electrochemical Impedence Spectroscopy revealed that the plot associated composite coating exhibited high charge transfer resistance compared to that of the AZ31. Furthermore, the Potentiodynamic polarization tests by shifting the corrosion potential towards the noble direction from −1.44 V to −1.27 V. The above findings underscore that the composite coating has the potential for in vivo and clinical trials.