Multifunctional nanoparticles based on magnetite/silica core-shell, consisting of iron oxides coated with
silica matrix doped with fluorescent components such as organic dyes (fluorescein isothiocyanate - FITC, Rhodamine
6G) or quantum dots, have drawn remarkable attention in the last years. Due to the bi-functionality of these
types of nanoparticles (simultaneously having magnetic and fluorescent properties), they are successfully used in
highly efficient human stem cell labeling, magnetic carrier for photodynamic therapy, drug delivery, hyperthermia
and other biomedical applications. Another application of core-shell-based nanoparticles, in which the silica is
functionalized with aminosilanes, is for immobilization and separation of various biological entities such as proteins,
antibodies, enzymes etc. as well as in environmental applications, as adsorbents for heavy metal ions. In vitro
tests on human cancerous cells, such as A549 (human lung carcinoma), breast, human cervical cancer, THP-1 (human acute monocytic
leukaemia) etc. , were conducted to assess the potential cytotoxic effects that may occur upon contact of nanoparticles with cancerous tissue.
Results show that core-shell nanoparticles doped with cytostatics (cisplatin, doxorubicin, etc.), are easily adsorbed by affected tissue
and in some cases lead to an inhibition of cell proliferation and induce cell death by apoptosis.
The goal of this review is to summarize the advances in the field of core-shell materials, particularly those based on magnetite/silica with
applicability in medicine and environmental protection. This paper briefly describes synthesis methods of silica-coated magnetite
nanoparticles (Stöber method and microemulsion), the method of encapsulating functional groups based on aminosilanes in silica shell,
as well as applications in medicine of these types of simple or modified nanoparticles for cancer therapy, MRI, biomarker immobilization,
drug delivery, biocatalysis etc., and in environmental applications (removal of heavy metal ions and catalysis).