Preparation and description of magnetic modified colloidal particles of silicon dioxide for recognition of HeLa cells

Modification of the cell surface by the methods of nanoarchitectonics allows changing the physical and chemical properties of cells. Thus, it is possible to get imprinted colloid particles based on template cells that are able to recognize and selectively attach to cells. Application of nanomaterials in the inorganic coating composition expands their biomedical potential. For example, doping of cell imprints with magnetic nanoparticles allows manipulating the cells associated with shell fragments by the external magnetic field. In this work, we developed colloidal cell imprints based on silicon dioxide doped with iron oxide magnetic nanoparticles capable of binding to HeLa cells. The method of chemical coprecipitation was used to synthesize iron oxide magnetic nanoparticles. The hydrodynamic size and ζ-potential of nanoparticles were measured by the dynamic light scattering method. The morphology of magnetic nanoparticles was analyzed with the help of transmission electron microscopy and dark-field microscopy. The sol-gel process was used to coat HeLa cells by silicic acid derivatives doped with magnetic nanoparticles. Coating formation on cells was observed with scanning electron microscopy. Colloid cell imprints were obtained after the breakage of the inorganic coating by the ultrasonic treatment. Subsequently, colloid particles were cultivated with the HeLa cell line and observed with bright-field microscopy. Additionally, the morphology of the coating and cell imprints was visualized by the atomic force microscopy. Spherical magnetic nanoparticles with a diameter of about 110 nm were obtained. Silica coating formation on the HeLa cells was demonstrated. Furthermore, it was established that colloid imprints obtained after the decomposition of the silica-based shell are capable of binding to cells. Therefore, we successfully manipulated the cells coated with the silica-based shell doped with magnetic nanoparticles.