Multifunctional hybrid nanosystems based on mesoporous silica and hydroxyapatite nanoparticles applied as potential nanocarriers for theranostic applications

In recent years, nanomaterials with properties such as biocompatibility, high specific surface area, and narrow pore distribution have been extensively studied for the treatment of cancer patients. These materials can be loaded with anti-tumor agents to promote a targeted delivery of drugs, reducing the occurrence of side effects common in conventional treatments. However, the ideal characteristics for biomedical applications are not often found combined in a single material, causing the need for the creation of systems composed of more phases to achieve the best material for such applications. Mesoporous silica nanoparticles are promising materials for this purpose, considering the possibility to incorporate organic and inorganic phases into this matrix, such as sensitive polymers, hydroxyapatite (HA) nanoparticles, and rare-earth elements, creating a theranostic material-a single hybrid compound with multifunctionality and capable of performing diagnostic and treatment functions simultaneously. In this study, we report the production of a europium-doped mesoporous silica/hydroxyapatite nanocomposite functionalized with the pH-sensitive polymer poly(methacrylic acid)-P(MAA). The samples were characterized by XRD, FTIR, CHN, TGA, SEM, TEM, XRF, N-2 adsorption, and PL techniques. Incorporation and release assays using the antitumor drug methotrexate were performed to evaluate the potential use of these materials as drug carriers in cancer therapy. The results show the photoluminescent potential of these systems, due to the europium doping, and the pH-dependent response in drug release, due to the P(MAA) functionalization. In conclusion, data from this work show that these hybrid nanocomposites exhibit adequate characteristics to be used as a drug delivery platform.