Mechanisms of calcium phosphates formation on inorganic nanomaterials. A biomimetic synthetic route for multifunctional nanocomposites for hard tissue regeneration.
Population ageing and modern way of life lead to the increased frequency of chronical diseases. Among them, diseases affecting hard tissues (bone and teeth) attract special attention, since they are present in all age groups, significantly reduce patient quality of life and influence society in general. Frequently, the only possible treatment of such diseases is implantation of hard tissue implant materials with the aim to regenerate damaged or diseased tissue. In order to avoid two principle causes of implants failure, aseptic loosening and infection, as well as to prevent premature failure of the implant, a new, innovative implant materials are needed. The solution is sought in multifunctional materials, which in addition to replacing missing tissue or enabling its regeneration, as well as having improved mechanical properties, will act as local drug delivery system. Since no single material could satisfy all the conditions put on “ideal” material, the focus is turned to composite materials. In order for these materials to be functional and to rationalize their design, the interactions between their components should be understood. This, however, very often is not the case and success stories are often result of more empirical than a systematic approach.
New hard tissue regeneration biomaterials emerging in recent years are composite materials based on calcium phosphates (CaPs) and different inorganic nanomaterials (NMs). The aim of the proposed project is to systematically investigate the CaPs interactions with two types of inorganic NMs, namely:
a) titanium dioxide NMs of different morphology (nanoparticles, nanotubes, nanowires, nanoplates),
b) silver nanoparticles of different surface modification (poly(vinylpyrrolidone), PVP; citrate, cit; sodium bis(2-ethyl-hexyl) sulfosuccinate, AOT)
in order to determine the relationship between NMs interface properties (surface modification, morphology, surface charge density, crystal structure) and the properties of forming CaPs solid phase at conditions close to physiological. In addition, the influence of biologically active molecules, albumin and chitosan, on the formation of CaP on NMs will be investigated. Albumin is one of three soluble proteins which are immediately adsorbed on the surface of the implant, influencing its in vivo performance. Chitosan is a polysaccharide, with antimicrobial activity, which also reduces Ag+ toxicity while retaining its antimicrobial activity. The potential for application of CaP/NMs composites in novel biomaterials development will be determined using standard immunocompatibility and hemocompatibility tests.
Obtained results will contribute to the better understanding of the CaP precipitation processes at nanosurfaces and at the nanoscale. The systematic variation of key NMs characteristics influencing the precipitation processes (morphology, surface composition and surface charge density) could enable a more rational approach to the design and biomimetic synthesis of biomaterials, but as well as to the understanding of precipitation processes in vivo. Since precipitation processes are underlying many industrial processes, the obtained results could also contribute to the development of novel synthetic routes and materials for different applications.