Biomimetic approach to poly(ethyl methacrylate) solubilization, deposition, and coating loading with functional biomaterials

A biomimetic approach is described for the fabrication of poly(ethyl methacrylate) (PEMA) coatings by a dip coating method. In the proposed approach, bile acids, such as cholic acid and lithocholic acid, are used as solubilizing agents for PEMA in isopropanol. For the first time, PEMA coatings are fabricated from solutions in isopropanol avoiding the use of traditional toxic solvents. The feasibility of fabricating concentrated solutions of high molecular mass PEMA is a key factor for the deposition. The coatings can be obtained as monolayers or multilayers of controlled coating mass. The analysis of deposition yield data and chemical structures of the bile acids provides an insight into the deposition mechanism. The PEMA coatings provide corrosion protection of stainless steel. Building on advanced properties of bile acids, as natural dispersants, composite coatings containing various bioceramics, such as hydroxyapatite, silica, and titania in the PEMA matrix, are obtained. Tetracycline is used as a model drug for the fabrication of drug-containing PEMA coatings. It is found that other functional molecules, such as heparin, can be incorporated into the PEMA matrix. The approach developed in this investigation is promising for the fabrication of coatings for biomedical implants and devices using natural surfactants and avoiding the use of toxic solvents. Such coatings can be deposited as laminates of different layers, functionalized with bioceramics, drugs, and various biomolecules.