Mesoporous Silica–Fe₃O₄ Nanoparticle Composites as Potential Drug Carriers

Abstract

This work is an innovative study of ordered mesoporous silica (SBA-15) nanocomposites, with different morphologies, and superparamagnetic iron oxide nanoparticles (SPIONs), as promising drug delivery vehicles guided by magnetization. Incorporating SPIONs into SBA-15 is of great interest because it can improve controlled delivery of drugs as well as avoid agglomeration of the nanoparticles. SPIONs were prepared by coprecipitation and thermal decomposition methods and incorporated into SBA-15, with different morphologies, by the incipient wetness impregnation method. The nanocomposites (SBA-15:SPIONs) were characterized by physicochemical techniques, including small-angle X-ray scattering, X-ray diffraction, nitrogen adsorption−desorption isotherms, scanning and transmission electron microscopies, energy-dispersive spectroscopy, magnetization measurements, pair distribution function analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential thermal analysis. The X-ray diffraction and small-angle X-ray scattering data of the nanocomposites verified that the crystalline phase of magnetite (Fe 3 O 4 ) and the pore structure of the SBA-15 did not undergo significant changes. N 2 physisorption data evidenced significant changes in the textural properties of the pure SBA-15, indicating the incorporation of SPIONs into the mesopores, with greater incorporation when the nanoparticles are obtained by thermal decomposition, in agreement with the small-angle X-ray scattering results. Transmission electron microscopy images, energy-dispersive spectroscopy, and thermogravimetry results evidence the successful incorporation of SPIONs into the silica matrix. The SBA-15:SPIONs presented superparamagnetic behavior. The pair distribution function method revealed a significant variation in the local structure related to changes in the Si−Si−O coordination caused by the decrease in the SBA-15 particle size. The incorporation of SPIONs was better for silica with smaller particle sizes and a higher proportion of SPIONs. Biological assays, such as myelotoxicity and cell viability, demonstrated that the nanocomposites could be safe potential drug delivery vehicles.

Development of Ac2-26 Mesoporous Microparticle System as a Potential Therapeutic Agent for Inflammatory Bowel Diseases

“… 51–56 In fact, by modeling the SAXS data, in combination with the NAI results, it was possible to conclude that a fraction of the Ac2-26 peptide was loaded into the SBA-15 mesopores. In contrast, the remaining amount is on the silica surface, a similar scenario observed in previous studies, 44 , 57 in which the authors loaded proteins instead of peptides. As suggested by Rasmussen et al, 58 the biological content of the SBA-15 macroporosity is still being protected against harsh environmental conditions such as the TGI.…”

“…The obtained data are shown in Figure 1C (black-filled circles), and the obtained results are comparable to those previously reported for ordered mesoporous silica. [42][43][44] It is interesting to note that both curves, with and without peptide, are very similar. To describe their structure and eventual differences, we proceeded with the data analysis using the model fully detailed by Losito et al 2021a.…”

Electrospinning Preparation, Structure, and Properties of Fe3O4/Tb(acac)3phen/Polystyrene Bifunctional Microfibers

“…As can be seen from Figure 11 , all samples were superparamagnetic. When the external magnetic field was added, the samples were magnetic, and the magnetism of the samples disappeared when the external magnetic field was removed, which made it possible for them to be applied in the biomedical field [ 39 , 40 ]. The saturation magnetization values of the Fe 3 O 4 nanoparticles, samples 20Fe0Tb, 20Fe30Tb, 20Fe40Tb, and 20Fe50Tb, were 80.0, 1.1, 4.1, 6.1, and 7.4 emu/g, respectively.…”

Use of postbiotics and salicylic acid in a nanostructured system to control Cutibacterium acnes

“…The system was kept under constant agitation for 8 hours at 25°C, with 2 mL samples collected every hour. Contribuciones a Las Ciencias Sociales, São José dos Pinhais, v.17, n.6, p. 01-34, 2024 The ordered mesoporous silica, SBA-15, used for lipase incorporation, was synthesized and characterized following the methodology employed by Zhao et al (1998), with some modifications as per Losito (Losito et al, 2021). Briefly, 4 g of the structure-directing agent, Pluronic® P123, was solubilized in 30 mL of purified water and 120 mL of hydrochloric acid (2 M).…”