Microfluidic fabrication of size-controlled nanocarriers with improved stability and biocompatibility for astaxanthin delivery

Improving the stability of astaxanthin (AST) is a vital way to enhance its oral bioavailability. In this study, a microfluidic strategy for the preparation of astaxanthin nano-encapsulation system was proposed. Thanks to the precise control of microfluidic and the rapid preparation ability of the Mannich reaction, the resulting astaxanthin nano-encapsulation system (AST-ACNs-NPs) was obtained with average sizes of 200 nm, uniform spherical shape and high encapsulation rate of 75%. AST was successfully doped into the nanocarriers, according to the findings of the DFT calculation, fluorescence spectrum, Fourier transform spectroscopy, and UV-vis absorption spectroscopy. Compared with free AST, AST-ACNs-NPs showed better stability under the conditions of high temperature, pH and UV light with<20% activity loss rate. The nano-encapsulation system containing AST could significantly reduce the hydrogen peroxide produced by reactive oxygen species, keep the potential of the mitochondrial membrane at a healthy level, and improve the antioxidant ability of H₂O₂-induced RAW 264.7 cells. These results indicated that microfluidics-based astaxanthin delivery system is an effective solution to improve the bioaccessibility of bioactive substances and has potential application value in food industry.

Removable coatings: Thermal stability and decontamination of steel surfaces from 241Am

This study presents a comparative analysis of several commercial removable materials for radioactive decontamination of steel surfaces using ²⁴¹Am as representative radionuclide. The selection criteria of removable coatings for this study included a history of application, commercial availability, easy handling conditions and different composition and formulation. Carbon steel and stainless steel coupons were utilized as common industrial materials, and the experimental series were expanded to include the rusting treatment of these surfaces as it is common for decommissioned nuclear facilities. Radionuclide ²⁴¹Am was deposited on the coupon surfaces and used to evaluate decontamination efficiency of the removable coatings, which were pre-screened for the ease of application and removal from the surface. Selected coatings were characterized with Fourier-transform infrared spectroscopy and thermogravimetric analysis, decontamination efficiencies for different types of steel surfaces, and potential enhancement of the removal efficiencies of the select removable coatings via amendment with EDTA. Across all the coatings, decontamination efficiencies for stainless steel (both pristine and with oxidizing treatment) were higher than for pristine carbon steel, which in turn were higher than for rusted carbon steel. Amendment with EDTA improved removal efficiency of a removable coating. CC Strip coating exhibited easy handling and high decontamination efficiency, (up to 97% when EDTA-amended), but its drying time was the longest, and thermal analysis indicated higher release of energy during thermal decomposition compared to the other coatings. Hydrogel-based DeconGel coating, even though not the easiest in handling among the rest of materials, exhibited high decontamination efficiency, efficient drying at the ambient temperature leading to the loss of about 80 wt% due to solvent evaporation, and extremely low heat released during thermal decomposition; therefore, it is considered a preferable choice for the considered factors.

Development of soy protein isolate/κ-carrageenan composite hydrogels as a delivery system for hydrophilic compounds: Monascus yellow

The aim of the present study was to develop soy protein isolate (SPI) and κ-carrageenan (KC) composite hydrogels as a delivery system for hydrophilic compounds. The pigment of monascus yellow was used as a model. A systematic study was performed to characterize the rheological, textural, microstructural properties and in vitro digestion release profile of monascus yellow of the composite gels. The results of power law modeling, electrophoresis patterns and fourier transform infrared spectroscopy (FTIR) confirmed that non-covalent interactions were involved in the formation of SPI/KC composite hydrogels. Compared to pure κ-carrageenan hydrogels, the incorporation of SPI could promote the formation of tougher, more uniform and compact composite gels with sustained-release property. In addition, the release behaviors of monascus yellow entrapped in the hydrogel network can be well described by the Ritger-Peppas mathematical model. Overall, our study provided a promising strategy to enhance the sustained release performance of hydrogels in digestive conditions.

pH-shifting encapsulation of curcumin in egg white protein isolate for improved dispersity, antioxidant capacity and thermal stability

Curcumin (Cur) has many functions, such as antioxidant and anti-inflammatory. However, its poor solubility and thermal stability at aqueous solutions limit its application in the food industry. In this study, egg white protein isolate (EPI) was complexed with Cur via a pH-shifting method. The effects of ultimate pH (from 5.0 to 7.0) on the physicochemical properties of the complex were studied. Cur could reach 84.4% encapsulation efficiency at pH 6.0. Meanwhile, the EPI complex could remain stable at pH 7.0 after 30 days and protect Cur from thermal degradation, thereby improving the Cur retention rate with the increasing ultimate pH. Compared with those of EPI and free Cur, the antioxidant capacity of the complex was enhanced effectively. The EPI-Cur complex was certified using UV-vis and fluorescence spectra. The fluorescence results indicated that Cur and EPI are combined through a static quenching and with a strong affinity of 1.8 × 10⁵ M^-1 at pH 6.0. In summary, this work provides a biocompatible and straightforward method for the development of nanoparticles based on egg white protein isolates, which can be used as a promising carrier for insoluble nutritional compounds.

In Vivo Packaging of Protein Cargo Inside of Virus-Like Particle P22

Protein cages are ubiquitous in nature and have been manipulated to encapsulate a range of nonnative cargos including organic, inorganic, and small molecules. Many protein cages are derived from virus capsids that have been rendered noninfectious through the preferential production and use of proteins that are solely involved in capsid assembly, but which do not encapsulate genetic material and therefore do not contribute to infectivity. Here, we describe the production of protein cargo(s) encapsulated inside of P22 virus-like particles (VLPs), derived from bacteriophage P22. This is achieved via genetic fusion of the cargo to a scaffolding protein, which becomes encapsulated in the P22 VLP during templated assembly of the protein cage.

Idiopathic sclerosing encapsulating peritonitis: Abdominal cocoon

Abdominal cocoon, the idiopathic form of sclerosing encapsulating peritonitis, is a rare condition of unknown etiology that results in an intestinal obstruction due to total or partial encapsulation of the small bowel by a fibrocollagenous membrane. Preoperative diagnosis requires a high index of clinical suspicion. The early clinical features are nonspecific, are often not recognized and it is difficult to make a definite pre-operative diagnosis. Clinical suspicion may be generated by the recurrent episodes of small intestinal obstruction combined with relevant imaging findings and lack of other plausible etiologies. The radiological diagnosis of abdominal cocoon may now be confidently made on computed tomography scan. Surgery is important in the management of this disease. Careful dissection and excision of the thick sac with the release of the small intestine leads to complete recovery in the vast majority of cases.