Valeria Richmond

Visiting Student, Instituto Tecnológico de Costa Rica

Development of bioactive organic/inorganic composite coatings for bone regeneration based on bioactive glass particles, chitosan and alginate by electrophoretic deposition

 

Supervisors in Erlangen: Muhammad Asim Akhtar, Prof. Aldo R. Boccaccini
Supervisor in Costa Rica: Dr. Luis Cordero-Arias

Coatings on the surface of metallic implants play a key role by decreasing the corrosion degradation of the implant and the related risk associated with the release of ions (e.g. Ni, Ti, Cr)  into the body. On the other hand, coatings based on bioactive materials, e.g. bioactive glass (BG), and biopolymers impart bioactivity to the coating increasing the bone-implant attachment and in some cases reducing the infection risk [1]. Electrophoretic deposition (EPD) is a competent technique for making such coatings [2]. In this work, a series of BG-biopolymer coatings will be characterized to determine which coating has the best bioactivity, mechanical properties and corrosion resistance. Melt derived BG (micro)particles and BG nanoparticles have been used in the development of single layer biocompatible coatings to modify the surface of AISI 316L medical grade alloy substrates by EPD [1, 3]. Colloidal suspensions were developed with alginate (Alg) and chitosan (Ch) as stabilizing biopolymers. In order to carry out a comparative study between the different coatings, bioactivity tests will be also performed. The morphology and composition of the coatings will be studied through SEM, optical profilometry, FTIR, and bending test. Contact angle will be measured to assess the possibility of protein attachment. The electrochemical behavior of the coatings will be analyzed through measurements of open circuit potential (OCP), Electrochemical Impedance Spectroscopy (EIS) and Polarization Curves (PC).

[1] M. Miola, et al., Electrophoretic Deposition of Chitosan/45S5 Bioactive Glass Composite Coatings Doped with Zn and Sr, Front. Bioeng. Biotechnol. 3 (2015) 159.

[2] A. R. Boccaccini, et al., Electrophoretic deposition of biomaterials. J. R. Soc. Interface 7 (2010) 581–613.

[3] Q. Chen, et al. Alginate/bioglass® composite coatings on stainless steel deposited by direct current and alternating current electrophoretic deposition. Surf. Coat. Technol. 233 (2013), 49–56.