Electrophoretic Deposited Silk Fibroin/Gentamicin Coatings On 3D-printed Porous Co-Cr Prosthesis

Background:With its tailored shape, better wear resistance than titanium, and Young's modulus matching the bone around, 3D-printed porous Co-Cr prosthesis is now one of the hottest areas of artificial joint prosthesis. However, there are two problems on the clinical use of porous prosthesis. One is how to induce the bone to grow in the pores and another is how to prevent the postoperative infection. Electrophoretic deposited solution can get into the inner of the porous structure, which makes it possible to fabricate the coatings on the inner surface of the porous structure. Electrophoretic deposited coatings can also be drug release system. Silk fibroin has good biocompatibility and we found that it can be electrophoretic-deposited in aqueous solution with little bubble which makes it suitable to fabricate the coatings on the inner surface of the porous structure. Moreover, the neutral water environment can decrease the adverse reaction of drugs which are not stable to alcohols and acids. However, the electrophoretic deposited silk fibroin/ gentamicin coatings are formed on anode, and anode can have electrochemical corrosion on the metal surface. The influence by the electrochemical corrosion of electrophoretic deposition has not been reported yet. Gentamicin is a cheap antibiotic and with a broad antifungal spectrum, but as it has ototoxicity and nephrotoxicity, it is always used as local medication. This study fabricated electrophoretic deposited silk fibroin/ gentamicin coatings on 3D-printed porous Co-Cr prosthesis. Methods:Silk fibroin and gentamicin have on covalent bonding in the solution, and they may form the coating via co-deposition mechanism. 20 V and 1min are proper parameter. The coatings were deposited on the inner surfaces of porous prosthesis uniformly. Although the electro-chemical corrosion of cathode exists, the mechanical property of the porous prosthesis had not been worse. Also the initial cell response and the antibacterial drug release function of the coatings were demonstrated good. ConclusionWe fabricated the electrophoretic deposited silk fibroin/ gentamicin coatings on the inner surfaces of 3D-printed porous prosthesis uniformly, and this may provide a new method for fabricating functional coatings on porous structures.