Electrophoretic deposition of chitosan-based composite coatings for biomedical applications: A review

Chitosan is one of the most widely used natural biopolymers for a great variety of biomedical applications owing to its biocompatibility, biodegradability, and antibacterial activity, being generally regarded as a safe material. It can be employed as a dispersant, binder, and surface charge agent for particles in suspension. Electrophoretic deposition (EPD) of chitosan, especially in combination with other materials, is receiving increasing attention for biomedical applications. This article presents a comprehensive review of the field of EPD of chitosan-based composite coatings by highlighting their microstructural, mechanical, surface, and biological properties. Since suspension characteristics have significant influences on the deposition mechanisms, kinetics, and on the overall properties of the electrophoretically deposited coatings, suspension parameters such as concentration, viscosity, and zeta potential are discussed, including chitosanbased suspensions with hydroxyapatite, bioactive glass particles, carbonaceous materials and other inorganic and organic materials. The deposition mechanisms proposed for each composite system are highlighted. Moreover, the effects of key EPD process parameters on the micro structural homogeneity, mechanical properties as well as surface and biological characteristics of the coatings are emphasised, and specific approaches for future research are proposed based on the state-of-the-art and considering EPD produced chitosan-based coatings in applications such as tissue engineering and drug delivery systems.