Síntese de partículas esféricas e submicrométricas de vidro bioativo com a incorporação de estrôncio e icariin e avaliação do seu potencial osteogênico em células tronco mesenquimais de ratas com osteoporose

Abstract

Osteoporosis is the metabolic disease that most often affects bone tissue. One of the major challenges related to the disease is its associated fractures and its conventional treatments. One of the difficulties present in these treatments is related to their low bioavailability and one of the options to improve this problem would be the use of systems for the local release of therapeutic agents. The use of bioactive glasses as multifunctional release systems allows the combination of the effects present in ions and drugs, with the advantages related to this inorganic material. Among the agents that can be used for bone, the repair is strontium ion and phytopharmaceutical icariin, which have the potential to prevent bone loss and / or increase bone formation. Initially, the influence of the incorporation of different Sr concentrations on the structure and properties of bioactive glasses was evaluated. Submicron and spherical particles of Sr containing bioactive glass with controlled ion release capacity in the physiological medium were obtained. The chemical composition analysis confirmed the presence of Sr2+ in the samples that also presented high surface area and mesopores. It was observed that the addition of Sr caused changes in the characteristics of bioactive glasses. Due to the importance of calcium in the differentiation process, biological tests were performed only on the particles containing this ion in composition. The results showed that the particles had no negative effects on cell viability and were able to improve the differentiation potential of rat osteoporotic bone marrow mesenchymal stem cells. These same particles were successfully incorporated with icariin, and it was observed that the amount of strontium present in the composition influenced the efficiency of incorporation and release of this phytopharmaceutical. Differentiation assays with Sr2+ and icariin-containing particles showed that these materials have the ability to improve differentiation of BMSC of osteoporotic rats but further studies are needed to better understand the mechanisms of these properties. Thus, the studied particles have great potential for use as a multifunctional system for the co-release of strontium and icariin.