In vitro biocompatibility study of sub-5 nm silica-coated magnetic iron oxide fluorescent nanoparticles for potential biomedical application

Abstract

Magnetic iron oxide nanoparticles (IONPs), for their intriguing properties, have attracted a great interest as they can be employed in many different biomedical applications. In this multidisciplinary study, we synthetized and characterized ultrafine 3 nm superparamagnetic water-dispersible nanoparticles. By a facile and inexpensive one-pot approach, nanoparticles were coated with a shell of silica and contemporarily functionalized with fluorescein isothiocyanate (FITC) dye. The obtained sub-5 nm silica-coated magnetic iron oxide fluorescent (sub-5 SIO-Fl) nanoparticles were assayed for cellular uptake, biocompatibility and cytotoxicity in a human colon cancer cellular model. By confocal microscopy analysis we demonstrated that nanoparticles as-synthesized are internalized and do not interfere with the CaCo-2 cell cytoskeletal organization nor with their cellular adhesion. We assessed that they do not exhibit cytotoxicity, providing evidence that they do not affect shape, proliferation, cellular viability, cell cycle distribution and progression. We further demonstrated at molecular level that these nanoparticles do not interfere with the expression of key differentiation markers and do not affect pro-inflammatory cytokines response in Caco-2 cells. Overall, these results showed the in vitro biocompatibility of the sub-5 SIO-Fl nanoparticles promising their safe employ for diagnostic and therapeutic biomedical applications.

Cellulose Silica Hybrid Nanofiber Aerogels: From Sol–Gel Electrospun Nanofibers to Multifunctional Aerogels

“…and displayed in Figure F,I. However, Figure C,D show major changes in the spectra of hybrid NFA displaying disappearance of the broad –OH band between 3400–3500 cm −1 and also of the band at around 1635 cm −1 attributed to bending vibrations of –OH group . There is also a rise in the strength of Si–O–Si characteristic bands located at 790 and 1070 cm −1 which can be attributed to increase in the asymmetry of the silica network and also to the development of stronger Si–O–Si linkages on thermal treatment .…”

“…Apart from greater chances of increased condensation of silanol groups to generate Si–O–Si linkages in the silica network during thermal treatment of the hybrids, possibility of loss of symmetry in the silica network because of crosslinking can also be responsible for this asymmetry, since only a crosslinked sample is capable to exhibit reduced solubility and enhanced mechanical stability. A closer look at the enlarged spectra of hybrid NFA (Figure D) demonstrates formation of a new peak as a shoulder of the Si–O–Si peak at 1051 cm −1 which is in fact a representative band for Si–O–C asymmetric stretching vibration . Quite interestingly this linkage was neither present in pure silica nor in CDA (FTIR spectra shown in Figure S8, Supporting Information) and is indicative of possible crosslinking reaction between CDA and surface silanol groups of silica during thermal treatment as intensity of the peak rises with increasing temperature.…”

Cytotoxic and Antiproliferative Effects of Nanomaterials on Cancer Cell Lines: A Review

“…eukaryotic cells, have been widely studied [10]. Proteins, lipids or any biomolecule may be absorbed by NPs, affecting not only the original synthetic structure but its biological effect.…”

Engineering surface-enhanced Raman scattering strategies for liquid biopsy analyses: a step towards precision medicine in cancer management

“…30 Generally, strong electromagnetic fields (termed as "hot spots") could be created by sharp tips, 31 vertices, 32 nanoporous frameworks in nanostructures, 33 intra-nanogaps within nanostructures, [34][35][36][37] and crevices or inter-nanogaps between nanostructures. [38][39][40][41][42][43][44] The enhancement efficiency of a hot spot is affected by many factors, such as curvature degree, gap size between nanostructures, and laser polarization. [45][46][47] Recent progress has produced high-performance plasmonic nanomaterials with excellent uniformity, reproducibility, and stability.…”

“…39 Additionally, the biocompatible nature of silica and BSA coatings increases the suitability of SERS nanotags for biomedical applications. 40,41 SERS nanotags with silica/BSA coatings have been used for intracellular pH probing 41 and multiplexed SERS detection. 42 However, silica or BSA coatings of all SERS nanotags in the sample are required for the maximum stabilization effect-without which-accurate, reproducible, and quantitative SERS detection without aggregation artifacts cannot be guaranteed.…”