Combination of magnetic field and surface functionalization for reaching synergistic effects in cellular labeling by magnetic core–shell nanospheres

Abstract

Aimed at utilizing high-magnetization nanospheres for magnetic field-enhanced cellular labeling, coreshell structured sandwich-like magnetic mesoporous silica nanospheres were developed. While the magnetite cluster core can provide a high magnetic response for overcoming Brownian motion in cell culture media, the layered silica shell facilitates an efficient fluorescent dye labeling. However, the problem of particle aggregation in cell media, which is strongly enhanced under a magnetic field, significantly impeded the uptake by cells, resulting in difficulties in the precise analysis of the degree of particle internalization by fluorescence-based techniques (flow cytometry and confocal microscopy). To overcome this, reflection-based assessment was employed. Further, emphasis was put on utilizing the unique role of surface-hyperbranched polyethylenimine (PEI) in efficient prevention of particle aggregation prior to cell internalization in the presence of an external magnetic field. The interparticle attraction forces originating from magnetic dipole-dipole interactions are hereby balanced by the steric and electrostatic repulsion forces provided by the PEI functionalization, which leads to dispersed nanospheres in cell culture media during the magnetic-field induced cell labeling. As a consequence, PEI functionalization and the presence of the magnetic field synergistically enhanced the efficiency of MRI-fluorescence dual-mode labeling for cellular tracking.

Preparation and characterization of higher degree‐deacetylated chitosan‐coated magnetic adsorbent for the removal of chromium(VI) from its aqueous mixture

“…99.5% pure acetic acid, magnesium sulfate, sodium phosphate, sodium carbonate, sodium bicarbonate, sodium silicate, potassium fluoride were purchased from Fisher scientific, Mumbai. All analytical solutions were prepared by the utilization of deionized water …”

Recent Advances in the Synthesis, Surface Modifications and Applications of Core‐Shell Magnetic Mesoporous Silica Nanospheres

“…Through surface modifications, new properties and applicability of coreshell Mag-MSNs are imparted. [84][85][86][87] At present, there are two major types of surface modifications methods for core-shell Mag-MSNs, namely, physical methods and chemical methods. [43]…”

“…To make the core‐shell Mag‐MSNs materials available in more application scenarios, the research on the surface modifications of core‐shell Mag‐MSNs is increasing in recent years. Through surface modifications, new properties and applicability of core‐shell Mag‐MSNs are imparted . At present, there are two major types of surface modifications methods for core‐shell Mag‐MSNs, namely, physical methods and chemical methods …”

A hybrid magnetic core–shell fibrous silica nanocomposite for a chemosensor-based highly effective fluorescent detection of Cu(ii)

“…Very importantly, the thickness of the fabricated silica prevents the uorescence energy transfer process (FRET) between the magnetic core-shell and the uorophore. 32 Finally, the nanocomposite (Fe 3 O 4 /MnO 2 /SiO 2 ) is modied with brous silica on the outer surface. The brous mesoporous silica surface could be easily functionalized with a silane reagent (APTES), on the surface moieties, such that sensing molecules of rhodamine B derivatives are uniformly covered on the silica surface.…”