Phytic Acid-Promoted rapid fabrication of natural polypeptide coatings for multifunctional applications

Surface modification or reconstruction of biomaterials, medical devices or other materials hold great promise for improved functionality and applications. However, it is essential to develop coating layers possessing a wide range of functionalities, such as antibacterial, anticorrosive and biocompatible properties. In this work, a simplified method was investigated for the supramolecular assembly of natural bio compounds, phytic acid (PA) and antimicrobial peptide of ε-polylysine (Ply), via one-pot co-deposition. The PA and Ply formed a coating layer on the substrate surface through the inherent surface affinity of PA and ionic bond formation between the electro-positive Ply and electro-negative PA. The co-deposition of PA-Ply is a surface-independent. The physio-chemical features of PA-Ply on titanium (Ti) were characterized to reveal the polymer decoration, surface composition, and microtopography. It was noticed that the PA-Ply coating on Ti (Ti-PA-Ply) could kill greater than 99.9% of both Gram-positive and Gram-negative bacterial pathogens upon their adhesion as compared to that of the pristine Ti surface. Furthermore, the in vivo rat subcutaneous infection model demonstrated effective anti-infection and bactericidal properties of the Ti-PA-Ply surface. In addition, the PA-Ply coating exhibited anti-corrosive property for medical-grade magnesium (Mg) in an electrochemical corrosion model, and promoted the proliferation of endothelial cells. The versatile PA-Ply coating also imparted an improved anti-fogging performance. Thus, the present one-step co-depostition of PA-Ply provided a simple, envirementelly-benign and sustainable approach to the design and fabrication of multi-functional surfaces.