Multifunctional Plasma-Polymerized Film: Toward Better Anticorrosion Property, Enhanced Cellular Growth Ability, and Attenuated Inflammatory and Histological Responses

Over the past few decades, plasma surface modification technique has been widely used to selectively improve surface properties and biocompatibility of materials. In this paper, at first a simple and effective method for the deposition of plasma-polymerized allylamine films onto 316L stainless steel (SS) from an allylamine/nitrogen gas mixture was developed. These amine-rich films were characterized by grazing incidence attenuated total reflection Fourier transform infrared spectroscopy (GATR-FTIR) and X-ray photoelectron spectroscopy (XPS), and the anticorrosion properties were demonstrated by electrochemical analysis. Micro-BCA and quartz crystal microbalance with dissipation (QCM-D) results showed that the higher density of amine groups of the allylamine-nitrogen plasma-polymerized film contributes to more serum protein adsorption which may enhance the adhesion and growth of cells on biomaterials. The in vitro and in vivo anti-inflammatory evaluation was performed and it has been confirmed that these nitrogen-rich surfaces could inhibit the activation of macrophages by down-regulation of the pro-inflammatory cytokines TNF-α and IL-6, and exhibit acceptable tissue-compatibility. It was found that with the help of nitrogen, plasma-polymerized allylamine films presented superior biological properties and provided a high potential application in surface modification of biomedical substrate with desirable clinical performance.