3D pritting of bioactive and resorbable scaffolds by robocasting: synthesis, processing and antibacterial activity

Abstract

Osteomyelitis is a typical bone infection mainly caused by the bacteria Staphylococcus aureus, followed by other species. Strategies aiming the development of bioactive and resorbable scaffolds, carriers with growth factors, drugs and nanoparticles have become an alternative to the treatment of this pathology, and is the focus of bone tissue engineering. Among used biomaterials to scaffolds manufacturing aiming bone tissue recovery and regeneration, the calcium phosphate-based ceramics stand out due to their similarly, in terms of structure and chemical composition, to mineral phase of bone, and their excellent biocompatibility. ²-tricalcium phosphate (²-TCP) is considered resorbable and has excellent osteoconductivity. In an attempt to achieve good densification of the ²-TCP scaffold and improve its biological properties, it arises the possibility to combine this material with S53P4 bioactive glass, which composition is 53% SiO2, 23% Na2O, 20 % CaO and 4 % P2O5 (wt.%). This bioglass also presents antibacterial property and is already used in the osteomyelitis treatment, in the form of granules. Several techniques are employed to bioceramic scaffolds production and among them, the robocasting, a type of additive manufacture which allows the production of customized parts, highly complex and good reproducible. Moreover, the ²-TCP/S53P4 scaffold surface can be modified by coating with nanoparticles capable of releasing therapeutic ions (Ag+, Zn2+, Cu2+) aiming to potentialize the scaffold antibacterial effect and consequently decrease the patient's infection incidences. In this context, this project aims to produce and characterize ²-TCP / S53P4 scaffolds by robocasting, followed by coating its surface with nanoparticles capable of releasing therapeutic ions, aiming at the treatment of osteomyelitis. The scaffolds will be characterized by their morphological, physical, mechanical and biological properties, as well as their antibacterial activity in different cultures of microorganisms. (AU)