Enhanced corrosion resistance and antibacterial activity of Zn-HA decorated MWCNTs film coated on medical grade 316L SS implant by novel spray pyrolysis technique

With the increase of bioimplants surgery, there is need to develop the new bioactive materials with good antibacterial activity and corrosion resistance of implants made of stainless steel. In the present work, we report the bioactivity of HA/CNT and the hybrid Zn-HA/MWCNT thin films prepared on medical grade 316 L SS substrate by spray pyrolysis technique. The coated films were characterized using X-ray diffraction, FTIR, and FE-SEM. The structural analysis of the film shows change in the lattice parameter and crystallite size after Zn addition into the HA/MWCNT composite. The shifting in the FTIR spectra at the range of 400- 900 cm−1 confirms the successful doping of Zn. SEM micrograph shows the transformation of spherical HA particle to hexagonal rod like particle bundled around the carbon nanotubes beneficial for bioimplant applications. Gram negative bacteria revealed higher zone of inhibition of 16 mm for zinc substituted sample compared with the value of 13 mm recorded for with HA/MWCNT. Potentialdynamic polarisation spectra of the hybrid Zn-HA/MWCNT coated implant revealed a higher Ecorr and Icorr values of −278 mV and 4.2 μA compared to bare HA/MWCNT. The polarisation and antibacterial study confirms that the Zn modified HA/MWCNT coated implant prevents the formation of bio-film, bacterial adhesion and release of metal ions from the implant.