RESUMEN
Although several materials are being studied for the development of theranostic systems, factors such as high costs, low yield, stability of nanoparticles (NPs) and toxicity-related issues hinder their application in medicine. Thus, this paper introduces the synthesis of a theranostic system composed of hydroxyapatite (HAp) functionalized with europium (Eu3+) and zinc oxide (ZnO) NPs, resulting in a low-cost material that presents biocompatibility, luminescence, antibacterial activity and whose synthesis method is simple. The Eu3+ - doped HAp was obtained through the precipitation method and the functionalization with ZnO occurred in the subsequent stage through the solid-state reaction method. The resulting material, [Ca9.5Eu0.5(PO4)6(OH)2@ZnO], was characterized by several techniques where the photoluminescence spectrum exhibited sharp peaks at the 4fN â 4fN transitions typical of Eu3+ ions, while tests with bacteria proved its antibacterial property. The crystal structure obtained by X-ray diffraction confirmed HAp as the major phase. The multifunctional HAp (HAp:Eu@ZnO) was considered as hemocompatible, exhibiting an in vitro hemolysis ratio of 1.85 (±0.2) %, and its loading potential, tested for two antitumor drugs, showed an adsorption capacity of 43.0 ± 3.6% for 5-Fluorouracil and 84.0 ± 4.0% for curcumin. The cytotoxicity of the system as well as its use as a support for drugs was analyzed through in vitro assays with tumor cells from sarcoma 180 in mice. The results confirmed that HAp:Eu@ZnO is non-toxic to cells and its potential for antineoplastic vectorization is increased by cell internalization due to endocytosis, with up to 39.0% of cancer cell deaths having been observed at the concentrations and period evaluated.