A Ferrofluid with Surface Modified Nanoparticles for Magnetic Hyperthermia and High ROS Production

A ferrofluid with 1,2-Benzenediol-coated iron oxide nanoparticles was synthesized and physicochemically analyzed. This colloidal system was prepared following the typical co-precipitation method, and superparamagnetic nanoparticles of 13.5 nm average diameter, 34 emu/g of magnetic saturation, and 285 K of blocking temperature were obtained. Additionally, the zeta potential showed a suitable colloidal stability for cancer therapy assays and the magneto-calorimetric trails determined a high power absorption density. In addition, the oxidative capability of the ferrofluid was corroborated by performing the Fenton reaction with methylene blue (MB) dissolved in water, where the ferrofluid was suitable for producing reactive oxygen species (ROS), and surprisingly a strong degradation of MB was also observed when it was combined with H2O2. The intracellular ROS production was qualitatively corroborated using the HT-29 human cell line, by detecting the fluorescent rise induced in 2,7-dichlorofluorescein diacetate. In other experiments, cell metabolic activity was measured, and no toxicity was observed, even with concentrations of up to 4 mg/mL of magnetic nanoparticles (MNPs). When the cells were treated with magnetic hyperthermia, 80% of cells were dead at 43 °C using 3 mg/mL of MNPs and applying a magnetic field of 530 kHz with 20 kA/m amplitude.

Impact of Enzymatic Hydrolysis and Microfluidization on the Techno-Functionality of Oat Bran in Suspension and Acid Milk Gel Models

Oat bran is a nutritionally rich ingredient, but it is underutilized in semi-moist and liquid foods due to technological issues such as high viscosity and sliminess. The aim of this work was to improve the technological properties of oat bran concentrate (OBC) in high-moisture food applications by enzymatic and mechanical treatments. OBC was hydrolyzed with β-glucanase (OBC-Hyd) and the water-soluble fraction (OBC-Sol) was separated. OBC, OBC-Hyd and OBC-Sol were further microfluidized at 5% dry matter content. Enzymatic treatment and microfluidization of OBC reduced the molecular weight (Mw) of β-glucan from 2748 kDa to 893 and 350 kDa, respectively, as well as the average particle size of OBC (3.4 and 35 times, respectively). Both treatments increased the extractability of the soluble compounds from the OBC samples (up to 80%) and affected their water retention capacity. OBC in suspension had very high viscosity (969 mPa·s) when heated, which decreased after both enzyme and microfluidization treatments. The colloidal stability of the OBC in suspension was improved, especially after microfluidization. The addition of OBC samples to acid milk gels decreased syneresis, improved the water holding capacity and softened the texture. The changes in the suspension and gel characteristics were linked with reduced β-glucan Mw and OBC particle size.

The Effect of pH and Sodium Caseinate on the Aqueous Solubility, Stability, and Crystallinity of Rutin towards Concentrated Colloidally Stable Particles for the Incorporation into Functional Foods

Poor water solubility and low bioavailability of hydrophobic flavonoids such as rutin remain as substantial challenges to their oral delivery via functional foods. In this study, the effect of pH and the addition of a protein (sodium caseinate; NaCas) on the aqueous solubility and stability of rutin was studied, from which an efficient delivery system for the incorporation of rutin into functional food products was developed. The aqueous solubility, chemical stability, crystallinity, and morphology of rutin (0.1–5% w/v) under various pH (1–11) and protein concentrations (0.2–8% w/v) were studied. To manufacture the concentrated colloidally stable rutin–NaCas particles, rutin was dissolved and deprotonated in a NaCas solution at alkaline pH before its subsequent neutralisation at pH 7. The excess water was removed using ultrafiltration to improve the loading capacity. Rutin showed the highest solubility at pH 11, while the addition of NaCas resulted in the improvement of both solubility and chemical stability. Critically, to achieve particles with colloidal stability, the NaCas:rutin ratio (w/w) had to be greater than 2.5 and 40 respectively for the lowest (0.2% w/v) and highest (4 to 8% w/v) concentrations of NaCas. The rutin–NaCas particles in the concentrated formulations were physically stable, with a size in the range of 185 to 230 nm and zeta potential of −36.8 to −38.1 mV, depending on the NaCas:rutin ratio. Encapsulation efficiency and loading capacity of rutin in different systems were 76% to 83% and 2% to 22%, respectively. The concentrated formulation containing 5% w/v NaCas and 2% w/v rutin was chosen as the most efficient delivery system due to the ideal protein:flavonoid ratio (2.5:1), which resulted in the highest loading capacity (22%). Taken together, the findings show that the delivery system developed in this study can be a promising method for the incorporation of a high concentration of hydrophobic flavonoids such as rutin into functional foods.

Theranostic Effect of Folic Acid Functionalized MIL-100(Fe) for Delivery of Prodigiosin and Simultaneous Tracking-Combating Breast Cancer

The metal organic framework (MOF) member, MIL-100(Fe), is considered as attractive drug nanocarrier that may be due to the great porosity, colloidal stability, and biocompatibility. In the present study, the new electrochemical synthesis procedure was presented for MIL-100(Fe) building block, and secondly, folic acid (FA) was introduced to the structure for assessing its potential targeted ability to be entrapped by folic acid-positive breast cancer cells, MCF-7. Several techniques such as SEM, XRD, and FT-IR were used to characterize synthesized nanostructures. Both MIL-100(Fe) and MIL-100(Fe)/FA nanoparticles were between 50 to 200 nm with a slightly positive net charge with an area of 1350 and 831.84 m2/g, respectively. The prodigiosin (PG) is selected as a model drug for MIL-100(Fe) and MIL-100(Fe)/FA-targeted delivery owing to its natural fluorescence and cancer cell selectiveness. The loading capacity of both nanocarrier was around 40% with 93-97% loading efficacy. Moreover, the pH-sensitive prodigiosin release rate of MIL-100(Fe)@PG and MIL-100(Fe)/FA@PG showed that 69 to 73% of the drug was released after 24 hours in an acidic environment with around 20% unwanted leakage. The anticancer potential MIL-100(Fe)/FA cells showed the improvement of selective index (SI) from 3.21 to 12.48 which means that folic acid acts as an effective ligand. The study of cells treated with fluorescence microscopy and flow cytometry analysis reveals the dependence of the receptor on the nanoparticle through endocytosis. Considering the effects of nanoparticles on healthy cells, MIL-100(Fe) and MIL-100(Fe)/FA nanoparticles can be introduced as targeted drug delivery systems for smart targeting breast cancer cells with minimal side effects.

Double-Layer Fatty Acid Nanoparticles as a Multiplatform for Diagnostics and Therapy

Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast agents, detection tags for in vitro biosensing, and mediators of heating in magnetic hyperthermia. One of the critical characteristics of nanoparticles to adjust to the biomedical needs of each application is their polymeric coating. Fatty acid coatings are known to contribute to colloidal stability and good surface crystalline quality. While monolayer coatings make the particles hydrophobic, a fatty acid double-layer renders them hydrophilic, and therefore suitable for use in body fluids. In addition, they provide the particles with functional chemical groups that allow their bioconjugation. This work analyzes three types of self-assembled bilayer fatty acid coatings of superparamagnetic iron oxide nanoparticles: oleic, lauric, and myristic acids. We characterize the particles magnetically and structurally and study their potential for resonance imaging, magnetic hyperthermia, and labeling for biosensing in lateral flow immunoassays. We found that the myristic acid sample reported a large r2 relaxivity, superior to existing iron-based commercial agents. For magnetic hyperthermia, a significant specific absorption rate value was obtained for the oleic sample. Finally, the lauric acid sample showed promising results for nanolabeling.

Impact of Molecular Chain Structure of Suspension Phase on Giant Electrorheological Performance

We demonstrate the impact of diester structure, in particular the alkyl chain length and branching structure, on the giant electrorheological (GER) effect and suspension stability. The existence of oil-particles interaction is of critical importance to induce the GER effect. To quantify GER performance and colloidal stability, we examine the yield stress, current density, field-off viscosity and sedimentation ratio with respect to the variation of chain length and branching structure. The oil-particles interaction is quantitatively analyzed by investigating the cluster size of particles in different diesters by a multiple light scattering analyzer, along with the wettability of different chain lengths of diesters and solid particles by the Washburn method. Our results indicate that long chain lengths favor the formation of particle agglomerates, thereby enhancing the GER effect (such as high yield stress). The attachment of branches on diester causes the formation of electronic correlation between branches and main chain, depending on the position of branches located, and hence results in superior GER performance and favorable suspension stability. An optimal GER fluid constituted by bis(2-ethylhexyl) sebacate is acquired with the achieved yield stress of 113 kPa at electric field strength of 4 kV/ mm and the prominent integrated GER properties.

Purification of quantum dot-based bioprobes with a salting out strategy

A salting out strategy is reported for purification of IgG-conjugated QD (IgG-QD) bioprobes. The optical properties, target recognition, and colloidal stability of the purified IgG-QD were commendably maintained after salting out.