Crypt-like patterned electrospun nanofibrous membrane and probiotics promote intestinal epithelium models close to tissues.

In vitro intestinal epithelium models have drawn great attention to investigating intestinal biology in recent years. However, the difficulty to maintain the normal physiological status of primary intestinal epithelium in vitro limits the applications. Here, we designed patterned electrospun polylactic acid (PLA) nanofibrous membranes with crypt-like topography and mimic ECM fibrous network to support crypt culture and construct in vitro intestinal epithelium models. The patterned electrospun PLA nanofibrous membranes modified with Matrigels at 0 °C showed high biocompatibility and promoted cell growth and proliferation. The constructed duodenum epithelium models and colon epithelium models on the patterned electrospun PLA nanofibrous membranes expressed the typical differentiation markers of intestinal epithelia and the gene expression levels were close to the original tissues, especially with the help of probiotics. The constructed intestinal epithelium models could be used to assess probiotic adhesion and colonization, which were verified to show significant differences with the Caco-2 cell models due to the different cell types. These findings provide new insights and a better understanding of the roles of biophysical, biochemical, and biological signals in the construction of in vitro intestinal epithelium models as well as the potential applications of these models in the study of host-gut microbes interactions. KEY POINTS: • Patterned electrospun scaffold has crypt-like topography and ECM nanofibrous network. • Matrigels at 0°C modify scaffolds more effectively than at 37°C. • Synergy of biomimic scaffold and probiotics makes in vitro model close to tissue.

The novel lactoferrin and DHA-codelivered liposomes with different membrane structures: Fabrication, in vitro infant digestion, and suckling pig intestinal organoid absorption.

Inspired by membrane structure of breast milk and infant formula fat globules, four liposomes with different particle size (large and small) and compositions (Single phospholipids contained phosphatidylcholine, complex phospholipids contained phosphatidylcholine, phosphatidylethanolamine and sphingomyelin) were fabricated to deliver lactoferrin and DHA. In vitro infant semi-dynamic digestive behavior and absorption in intestinal organoids of liposomes were investigated. Liposomal structures were negligible changed during semi-dynamic gastric digestion while damaged in intestine. Liposomal degradation rate was primarily influenced by particle size, and complex phospholipids accelerated DHA hydrolysis. The release rate of DHA (91.7 ± 1.3 %) in small-sized liposomes (0.181 ± 0.001 µm) was higher than free DHA (unencapsulated, 64.6 ± 3.4 %). Complex phospholipids liposomal digesta exhibited higher transport efficiency (3.4-fold for fatty acids and 2.0-fold for amino acids) and better organoid growth than digesta of bare nutrients. This study provided new insights into membrane structure-functionality relationship of liposomes and may aid in the development of novel infant nutrient carriers.

Natural biopolymer masks the bitterness of potassium chloride to achieve a highly efficient salt reduction for future foods.

Potassium chloride (KCl) can be considered as the most ideal salt replacer to reduce dietary sodium intake and ease various health risks of a high-sodium diet. However, a high proportion of sodium chloride (NaCl) replacement with KCl remains a challenge, because KCl has an inherent metallic bitterness. This study demonstrates a strategy for this bitterness-masking using a natural polysaccharide kappa-carrageenan to specifically bind with K+ and reduce the amount of free K+ as bitter stimulant. The results show that carrageenan can significantly slow down the release and diffusion of K+, leading to a reduced bitter taste of KCl in the mouth. Up to 50% replacement of NaCl by KCl can be achieved. Furthermore, the use of carrageenan-KCl-NaCl complex as salt substitutes can regulate mineral absorption (Na, K, Ca) and reduce hypertension and renal injury risks in the animal tests. In conclusion, this natural biopolymer-based strategy successfully masks the bitter of salt-replacer KCl, opening a route to the universally applicable salt-reduction in future foods.

A targeted and nontargeted metabolomics study on the oral processing of epicatechins from green tea.

Oral processing (OP), referring to the whole process of food digestion in human mouth, has a major influence on food flavor perception. This study focused on the compositional changes of the four green tea epicatechins (viz., EC, EGC, ECG, EGCG) during OP, based on targeted and nontargeted metabolomics. It was found that the four epicatechins were all extensively lost through transformation undergoing OP, among which EC was the most stable one, whereas EGCG the least. EGCG was further revealed to be susceptible to human oral cavity in the simulated OP in vitro. It could be converted physically by precipitating with mucin in saliva, and chemically through hydrolysis and dimerization, mediated mainly by the neutral pH condition. The OP of epicatechins also caused salivary composition changes possibly involving health benefits of green tea. These findings could raise awareness of the interactions between epicatechins, or any other food materials, with human mouth.

Sweet preference modified by early experience in mice and the related molecular modulations on the peripheral pathway.

The sweet taste is of immense interest to scientists and has been intensively studied during the last two decades. However, the sweet preference modification and the related mechanisms are still unclear. In this study, we try to establish a mice model with manipulated sweet taste preference and explore the involved possible molecular mechanisms. The animals were exposed to acesulfame-K via maternal milk during lactation and the sweet preference tests were carried out when they grew to adulthood. Our results showed that the preference thresholds for sweet taste were increased in adults by early acesulfame-K exposure and the preference ratios for sweet tastants at low or preferred concentrations were decreased. Moreover, by means of qRT-PCR and Western blot, we observed the increased expression of leptin receptor Ob-Rb and downregulation of Gα-gustducin protein in the soft palate. Thereby, the sweet taste sensitivity may be modified by early sweetener experience during lactation. Along the peripheral sweet sensory pathway, the sweet regulator receptors Ob-Rb, CB1 and components of sweet transduction signal Gα-gustducin and T1R2 in both the soft palate and tongue may be cooperatively involved in the plastic development of sweet taste.

Orderly ultrathin films based on perylene/poly(N-vinyl carbazole) assembled with layered double hydroxide nanosheets: 2D fluorescence resonance energy transfer and reversible fluorescence response for volatile organic compounds.

Neutral poly(N-vinyl carbazole) (PVK) and perylene are coassembled within the interlayers of layered double hydroxide (LDH) nanosheets to form (perylene@PVK/LDH)(n) ultrathin films by the hydrogen-bond layer-by-layer assembly method. An efficient 2D fluorescence resonance energy transfer (FRET) process from PVK to perylene is demonstrated, and this FRET process can be inhibited/recovered reversibly by the adsorption/desorption of common volatile organic compounds (VOCs).

Tailored extracellular matrix-mimetic coating facilitates reendothelialization and tissue healing of cardiac occluders.

Minimally invasive transcatheter interventional therapy utilizing cardiac occluders represents the primary approach for addressing congenital heart defects and left atrial appendage (LAA) thrombosis. However, incomplete endothelialization and delayed tissue healing after occluder implantation collectively compromise clinical efficacy. In this study, we have customized a recombinant humanized collagen type I (rhCol I) and developed an rhCol I-based extracellular matrix (ECM)-mimetic coating. The innovative coating integrates metal-phenolic networks with anticoagulation and anti-inflammatory functions as a weak cross-linker, combining them with specifically engineered rhCol I that exhibits high cell adhesion activity and elicits a low inflammatory response. The amalgamation, driven by multiple forces, effectively serves to functionalize implantable materials, thereby responding positively to the microenvironment following occluder implantation. Experimental findings substantiate the coating's ability to sustain a prolonged anticoagulant effect, enhance the functionality of endothelial cells and cardiomyocyte, and modulate inflammatory responses by polarizing inflammatory cells into an anti-inflammatory phenotype. Notably, occluder implantation in a canine model confirms that the coating expedites reendothelialization process and promotes tissue healing. Collectively, this tailored ECM-mimetic coating presents a promising surface modification strategy for improving the clinical efficacy of cardiac occluders.