Imparting of Nearly Superparamagnetic Properties to Cryogel Scaffolds With Mesoporous MNPs for Magneto-Sensitive Tissue Engineering Strategies.

This work reports the assembly of mesoporous iron oxide nanoparticles (meso-MNPs) with cryogel scaffolds composed of chitosan and gelatin. Meso-MNPs with a particle size ranging from 2 and 50 nm, a surface area of 140.52 m2 g-1, and a pore volume of 0.27 cm3 g-1 were synthesized on a porous SiO2 template in the presence of PEG 6000 followed by leaching of SiO2. Different ratios of meso-MNPs were successfully incorporated into chitosan:gelatin cryogels up to an amount equivalent to the entire amount of polymer. The morphological structure and physicochemical properties of the cryogels were directly affected by the amount of MNPs. VSM curves showed that all composite cryogels could be magnetized by applying a magnetic field. In the context of the safety of magnetic cryogel scaffolds for use in biomedicine, it is important to note that all values are below the exposure limit for static magnetic fields, and according to cytotoxicity data, scaffolds containing meso-MNPs showed nontoxicity with cell viability ranging from 150% to 275%. In addition, microbial analysis with gram-negative and gram-positive bacteria showed that the scaffolds exhibited activity against these bacteria.

Development of mesoporous magnetic nanoparticles supported idarubicin and investigation of apoptotic and cytotoxic effects on cancer cell lines.

BACKGROUND: Many methods are used for cancer treatment, especially chemotherapy. In addition to the their therapeutic effects, chemotherapeutic drugs also have serious disadvantages, such as not being cell and tissue-specific, causing toxicity in many tissues, and developing drug resistance. Many methods, especially nanocarriers, have been designed to overcome these disadvantages. METHODS AND RESULTS: In this study, we synthesized mesoporous silica iron oxide nanoparticles with different pore diameters and loaded idarubicin (6MFe3O4-NH2-IDA and 35MFe3O4-NH2-IDA). The synthesized molecules were characterized using FT-IR, XRD, and SEM methods. The cytotoxic effects of unbound idarubicin and idarubicin-loaded nanoparticles on MCF7 and HL-60 cell lines were examined by MTT test. Additionally, the expression of anti-apoptotic (Survivin and BCL-2) and apoptotic (BAX, PUMA, and NOXA) genes of the nanoparticles were measured by PCR method. As a result of the analyses, it was seen that nanoparticles with the desired properties and sizes were synthesized. In MTT analysis, it was observed that both nanoparticles dramatically decreased the IC50 value in cell lines. However, the 35MFe3O4-NH2-IDA molecule was found to have lower IC50 values. IC50 values ​​for pristine IDA, 6MFe3O4-NH2, and 35MFe3O4-NH2 at 24 h were found to be 3.56, 1.24 and 0.25 µM in the MCF7 cell line and 4.15, 1.16 and 0.34 µM in the HL-60 cell line, respectively. Additionally, apoptotic gene expression increased, and anti-apoptotic gene expression decreased. CONCLUSIONS: Our study demonstrates that the effectiveness of idarubicin can be significantly enhanced by its application with mesoporous nanocarriers. This enhancement is attributed to the controlled release of idarubicin from the nanocarrier, which circumvents drug resistance mechanisms, improves drug solubility, and increases the drug-carrying capacity per unit volume due to the porous structure of the carrier. These findings underscore the potential of the synthesized nanocarrier in cancer treatment and provide a clear direction for future research in this field.

Horseradish Peroxidase Immobilized onto Mesoporous Magnetic Hybrid Nanoflowers for Enzymatic Decolorization of Textile Dyes: A Highly Robust Bioreactor and Boosted Enzyme Stability.

Recently, hybrid nanoflowers (hNFs), which are accepted as popular carrier supports in the development of enzyme immobilization strategies, have attracted much attention. In this study, the horseradish peroxidase (HRP) was immobilized to mesoporous magnetic Fe3O4-NH2 by forming Schiff base compounds and the HRP@Fe3O4-NH2/hNFs were then synthesized. Under optimal conditions, 95.0% of the available HRP was immobilized on the Fe3O4-NH2/hNFs. Structural morphology and characterization of synthesized HRP@Fe3O4-NH2/hNFs were investigated. The results demonstrated that the average size of HRP@Fe3O4-NH2/hNFs was determined to be around 220 nm. The ζ-potential and magnetic saturation values of HRP@Fe3O4-NH2/hNFs were -33.58 mV and ∼30 emu/g, respectively. Additionally, the optimum pH, optimum temperature, thermal stability, kinetic parameters, reusability, and storage stability were examined. It was observed that the optimum pH value shifted from 5.0 to pH 8.0 after immobilization, while the optimum temperature shifted from 30 to 80 °C. K m values were calculated to be 15.5502 and 7.6707 mM for free HRP and the HRP@Fe3O4-NH2/hNFs, respectively, and V max values were calculated to be 0.0701 and 0.0038 mM min-1. The low K m value observed after immobilization indicated that the affinity of HRP for its substrate increased. The HRP@Fe3O4-NH2/hNFs showed higher thermal stability than free HRP, and its residual activity after six usage cycles was approximately 45%. While free HRP lost all of its activity within 120 min at 65 °C, the HRP@Fe3O4-NH2/hNFs retained almost all of its activity during the 6 h incubation period at 80 °C. Most importantly, the HRP@Fe3O4-NH2/hNFs demonstrated good potential efficiency for the biodegradation of methyl orange, phenol red, and methylene blue dyes. The HRP@Fe3O4-NH2/hNFs were used for a total of 8 cycles to degrade methyl orange, phenol red, and methylene blue, and degradation of around 81, 96, and 56% was obtained in 8 h, respectively. Overall, we believe that the HRP@Fe3O4-NH2/hNFs reported in this work can be potentially used in various industrial and environmental applications, particularly for the biodegradation of recalcitrant compounds, such as textile dyes.