Casein-quaternary chitosan complexes induced the soft assembly of egg white peptide and curcumin for ulcerative colitis alleviation.

Soft assembly of peptide and curcumin (Cur) molecules enables functional integration by finding dynamic equilibrium states through non-covalent interactions. Herein, we developed two soft assembly systems, curcumin-egg white peptides (Cur-EWP) aggregations (AGs) and Cur-EWP-casein-quaternary chitosan (Cur-EWP-CA-QC) nanoparticles (NPs) to comparatively investigate their therapeutic effects on ulcerative colitis in mice and elucidate their underlying mechanism. Results revealed that Cur-EWP AGs, despite gastrointestinal tract instability, exhibited a propensity for swift accumulation within the colorectal region, enriching mucus-associated and short-chain fatty acid (SCAF)-producing bacteria, restoring the intestinal barrier damage. Whereas, Cur-EWP-CA-QC NPs, benefiting from their remarkable stability and exceptional mucosal adsorption properties, not only enhanced permeability of Cur and EWP in the small intestine to activate the immune response and boost tight junction protein expression but also, in their unabsorbed state, regulated the intestinal flora, exerting potent anti-inflammatory activity. Soft assembly of peptides and hydrophobic nutraceuticals could synergize biological activities to modulate chronic diseases.

High-performance pyramid-SiNWs biosensor for NH3gas detection.

NH3is widely existed in the environment and is closely associated with various health issues. Additionally, detecting the small amounts of NH3exhaled by patients with liver and kidney diseases offers potential opportunities for painless early disease diagnosis. Therefore, there is an urgent need for a convenient, rapid, and highly sensitive real-time NH3monitoring method. This work presents a high-performance NH3sensor based on olfactory receptor-derived peptides (ORPs) on a pyramid silicon nanowires (SiNWs) structure substrate. First, we successfully fabricated the pyramid-SiNWs structure on a silicon substrate using a chemical etching method. Subsequently, by dehydrative condensation reaction between the amino groups on APTES and the carboxyl groups of ORPs, ORPs were successfully immobilized onto the pyramid-SiNWs structure. This methodology allows the ORPs sensor on the pyramid-SiNWs substrate to detect NH3as low as 1 ppb, which was the reported lowest limit of detection, with a higher response rate compared to ORPs sensors on flat SiNWs substrates. The sensors also exhibit good sensitivity and stability for NH3gas detection. The results show the feasibility and potential applications of ORPs-pyramid-SiNWs structure sensors, in the fields of food safety, disease monitoring, and environmental protection, etc.

The fabrication, characterization, and application of chitosan-NaOH modified casein nanoparticles and their stabilized long-term stable high internal phase Pickering emulsions.

The demand for facile delivery systems from natural biopolymers with long-term storage stability to deliver liposoluble nutraceuticals such as ß-carotene (BC) is increasing. In this work, a facile and reliable emulsifier of chitosan (CS)-NaOH-modified casein (CA) nanoparticles (NPs) was fabricated for the stabilization of high internal phase Pickering emulsions (HIPPEs) with versatile stability. Dynamic light scattering, TEM, FTIR, and interface tension results indicated that CS-CA NPs exhibited nanoscale (109-373 nm), positive charge (22-38 mV), pH-response, spherical in shape, assembled spontaneously by non-covalent interactions, and high surface activity. Optical microscopy, confocal laser scanning microscopy (CLSM), and rheometer results demonstrated that HIPPEs were emulsified by a dense and compact 3D network between the continuous phase and the interfacial region. Hence, the CS-CA NP-stabilized HIPPEs showed long-term storage stability (over 18 months at ambient temperature) and thermostabilization (1 month at 80 °C). The robust and compact CS-CA NPs dramatically declined the contents of primary and secondary oxidation production in HIPPEs than that by corn oil. Moreover, CS-CA NPs stabilized HIPPEs appreciably enhanced the bioaccessibility (2.56 times) and chemical stability (thermal, UV-light, and storage) of BC. This research evidenced that CS-protein or polysaccharide-CA-based systems could be an encouraging formulation to commercially construct tunable HIPPEs with adorable stability for liposoluble nutraceuticals with enhanced attributes.