Metallic biomaterials continue to play a crucial role in medical treatment, considering that approximately 80% of all clinical implant devices constitute of metals [1]. Nevertheless, the long-term stability of metallic implants presents a major challenge in orthopaedic applications due to their potentially poor osseointegration and proneness to bacterial infections. Even though antibiotic treatment remains a classical approach to counteract bacterial infections, the administration of inappropriate drug doses can potentially foster harmful side reactions, systemic toxicity or emergence of multidrug-resistant bacterial strains. Therefore, the concept of implant surface modification by applying coatings, which are able to promote the bone-binding ability of the device, while releasing antibacterial agents in a controlled manner in-situ, is gaining increasing attention. Among different coating techniques, electrophoretic deposition (EPD) benefits from simple processing equipment, versatility to coat complex shapes and the possibility to control the properties of the deposit by varying the process parameters [2]. The natural corn protein zein has been widely used as a coating material due to its attractive properties including biocompatibility, biodegradability and bioadhesiveness [3,4]. Thus, the current research project aims to develop bioactive and antibacterial composite coatings based on zein on titanium substrates by EPD. Different coating designs including single and double-layer coatings incorporating bioactive glass and phytotherapeutic drugs were investigated. The morphology, chemical composition, wettability, drug release behaviour, bioactivity and adhesion strength of the coatings were analysed. Additionally, cytocompatibility tests, as well as antibacterial assays against Gram-positive S. aureus and Gram-negative E. coli were performed. The results confirmed that the prepared coatings can be promising candidates to facilitate bone tissue integration and to prevent infections around orthopaedic and dental implants.

References

[1] T. Hanawa, Science and Technology of Advanced Materials, 2012, 13, 6.

[2] E. Avcu, et al., Progress in Materials Science, 2019, 103, 69-108.

[3] F. Maciag et al., Materials, 2021, 14, 312.

[4] N. Meyer et al., Coatings, 2018, 8, 27.