Keywords
Abstract
Magnetite nanoparticles (NPs) attract an attention of researchers due to their properties such as biocompatibility, biodegradation, magnetic behavior, and the presence of iron. Some of them are already approved for clinical use for diagnosis, treatment of cancer by hyperthermia, or therapy of iron deficiency. The use of NPs in medicine is determined by the processes at the biointerface, so modification of the NPs surface by functionalization is very important. The aim of the study is to analyze the literature data regarding the effect of surface modification of magnetite NPs on the features of their biomedical application. Literature sources were searched in PubMed and Google Scholar databases for the last 10 years. Inclusion criteria were reviews and original articles on preclinical studies. For the final analysis, 80 sources were selected, which were included in the main part of the review. Strict control of the physical and chemical properties of magnetite NPs can in most cases ensure the ability of a nanosystem to meet the requirements for which it was designed. However, magnetite NPs are characterized by rapid aggregation, reactivity, high surface energy, and a tendency to oxidize, which can change their properties. To prevent these phenomena, functionalization of the surface is applied. Surface bonding of magnetite NPs with metals is used to improve biocompatibility and induce the inert nature of the final nanostructure. Magnetic NPs coated with gold, platinum, and silver are described for the diagnosis and treatment of tumors, stimulation of regeneration, and antimicrobial action. Among oxides, silica coating is one of the most used approaches to modifying the surface of magnetic NPs. This is determined by a decrease in aggregation, an improvement in the stability and biocompatibility of NPs, the ability to be loaded by a large amount of medicinal substance molecules and their controlled delivery. The magnetite NPs functionalization by carbon and its compounds is of great importance for biology and medicine. It is carried out with the aim of improving stability, biocompatibility, and interaction with biological barriers. In the case of controlled drug delivery, organic compounds and especially polymers are the best coating materials, providing many available groups for conjugation with other molecules, which are anticancer agents, antibiotics, antioxidants, anti-inflammatory drugs. The main idea behind the functionalization of magnetite NPs with polymer is to increase stability. The longer the polymer chain, the higher the NPs stability. The conjugation of magnetite NPs with phytochemicals can provide them with additional therapeutic properties (antimicrobial, antitumor). Thus, the achievements of science contribute to the creation of magnetite NPs with clear structural characteristics, and the functionalization of the surface ensures the effectiveness of their biomedical application. The development of improved methods of biointerface coating is a key problem in the clinical use of magnetite NPs. The rational approach to the design of the functionalized magnetite NPs and their safety assessment in the near future can expand the practical use of these nanostructures due to drugs targeted delivery, tissue engineering, regenerative medicine, and the introduction of biosensores.