3D prevleke

Project title and ARRS code

J1-2470 Biofunctionalization of 3D-printed metal alloys as a newly emerging strategy to diminish undesired effects of orthopedic implants

Project group

Project leader: assoc. prof. Matjaž Finšgar Participating research organizations:

1. University of Maribor, Faculty of chemistry and chemical engineering
2. University of Maribor, Faculty of Medicine
3. University ob Maribor, Faculty of mechanical engineering
4. University of Nova Gorica

Project description

Developing strategies and solutions to avoid or minimize undesired side effects in the use of medical implants is still a partially unsolved challenge. In the early stage of healing, the body’s initial response to foreign material manifests as inflammation which can range from minimal local inflammation to an extensive and chronic foreign body reaction.  A factor that crucially influences the success of healing during this stage is implant's surface properties. The ultimate goal is that the recognition of the implant as a foreign body is impaired, usually by a careful choice of the external layer, thus minimizing the initial inflammatory cell response. The selection of scaffold materials and their architectural design play a very complex yet critical role in promoting bone regeneration by providing mimicry of the native bone matrix. Evidence suggests that modifying the implant surface in order that it better resembles extracellular matrix of healthy tissues results in increased osteointegration and osteoinduction of the implant. 3D-printing enables fabrication of complex structures ideally matched to the needs of each patient that take into account the patient-specific damage and minimize bone loss due to implantation requirements, while providing surfaces that more closely resemble the specific anatomy of the bone. Moreover, the use of customized surgical items has been show to markedly reduce surgical time, and enhance the medical outcome of the surgery, thus reducing the length of hospital stay. Wear, corrosion, and exposure to a changing environment after a long period of time, lead to macroscopic and microscopic changes of the metal implant material. Consequently, many unexpected implications on the surrounding tissues can occur, making the healthy environment of the implant vulnerable to infection. Advanced coatings can achieve a synergistic effect of bioactivity and high mechanical strength. More importantly, such coatings can protect the alloys by mitigating corrosion as a barrier against the release of metal ions into a highly corrosive biological environment. An effective therapy can only be provided by controlled drug release of all therapeutic agents. Whereas some drugs provide a desired release profile (their variable solubility leads to different release profiles in time), controlled drug release vehicles are usually required. The controlled release of  therapeutic agents is even more important in multidrug formulations, since these have to provide a multimodal therapy in space and time. The carrier materials for the active substances have to be biodegradable, yet sufficiently extensive knowledge regarding the interaction of the material components with the environment is often not available. Through detailed interaction studies the mechanical and release kinetics can be clearly understood and used as the fundamental knowledge to optimize the use of materials, and hence render the therapy safer, as well as effective. The objective of this project proposal is to develop novel bioactive multifunctional coatings on 3D-printed metal alloy substrates for orthopedic implants. The proposed project builds and upgrades the existing knowledge, as well as provides completely novel solutions regarding the coating preparation, achieving the coating’s bioactivity, and multifunctionality of the final material. The aim of each surgical procedure is to use the most efficient implant with the longest possible life span, and the best biocompatibility. This can only be accomplished by adapting the implant to the patient’s individual needs. Our approach promises to develop an “all-in-one” treatment that could provide the following benefits:

• decreased possibility of the artificial implant rejection due to anti-inflammatory action,
• prevention of infections during or after surgery,
• lower systemic risk of thromboembolic events,
• growth promotion of the desired osteoblasts either by the chosen materials or by the incorporated therapeutic agents.

Project stages

1. Preparation of 3D-printed materialswith enhanced chemical and metallurgical properties
2. Basic material formulation followed by systematic characterization of its properties
3. Preparation of novel complex and multifunctional bioactive coatings followed by their integration onto substrates
4. Corrosion tests
5. Study of the interaction phenomena in model and in vitrosystems
6. Evaluation of the: i) physicochemical, ii) structural and morphological, iii) bioactive functionality of the coated surfaces.
7. Biocompatibility studies and preclinical efficacy testing