Phospholipid Layer Research Articles

Gene reconstruction spandex with intrinsic antimicrobial activity

Polyhexamethylene guanidine hydrochloride (PHMG) was used as a functional “gene” to replace the diamine in ordinary spandex, and a “gene reconstruction” spandex (GRS) spinning solution was synthesized. Mixing a small amount of GRS spinning solution with ordinary spandex spinning solution, composite spandex (CS) with intrinsic antimicrobial activity was obtained by a dry-spinning process under a normal spinning condition. The TEM results indicated that PHMG in the GRS molecular chain was uniformly distributed in CS in a granular shape with 10–100 nm diameter and was aligned along the fiber axial direction with a chain-like structure. The inhibition rates of CS (containing 0.5 wt% PHMG) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) exceeded 99.99%. CS maintained excellent antibacterial properties after soaking in acetic acid solution at pH 3 for 45 min at 95 °C and showed strong intrinsic antimicrobial characteristics. Confocal laser scanning microscopy demonstrated that bacteria was quickly adsorbed on the surface of CS fiber, the cell membrane was damaged, and gradually bacteria died. The molecular simulation indicated that the positive charges accumulated on the PHMG surface, providing the driving force to attract bacteria with negative charge on the cell membrane phospholipid layer. TGA, DSC, XRD and mechanical property analysis confirmed that the corresponding performances of CS were better than those of ordinary spandex without GRS. In summary, the as-prepared CS by “gene reconstruction” eliminated the exudation problem of antibacterial agents in the traditional antimicrobial materials.

Neutral Diclofenac Causes Remarkable Changes in Phosphatidylcholine Bilayers: Relevance for Gastric Toxicity Mechanisms.

The main objective of this study was to clarify the topical mechanisms underlying diclofenac-induced gastric toxicity by considering for the first time both ionization states of this nonsteroidal anti-inflammatory drug. 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes were the model system chosen to mimic the protective phospholipid layers of the gastric mucosa and to describe the interactions with diclofenac, considering the pH gradient found in the gastric mucosa (3 < pH < 7.4). Complementary experimental techniques were combined to evaluate the drug's affinity for DMPC bilayers, as well as to assess the drug's effects on the structural properties of the phospholipid bilayer. The diclofenac-DMPC interactions were clearly dependent on the drug's ionization state. Neutral diclofenac displayed greater affinity for DMPC bilayers than anionic diclofenac. Moreover, the protonated/neutral form of the drug induced more pronounced and/or distinct alterations in the structure of the DMPC bilayer than the deprotonated/ionized form, considering similar membrane concentrations. Therefore, neutral diclofenac-induced changes in the structural properties of the external phospholipid layers of the gastric mucosa may constitute an additional toxicity mechanism of this worldwide-used drug, which shall be considered for the development of safer therapeutic strategies. SIGNIFICANCE STATEMENT: Neutral or anionic diclofenac exerted distinct alterations in phosphatidylcholine bilayers, which are used in this work as models for the protective phospholipid layers of the gastric mucosa. Remarkable changes were induced by neutral diclofenac in the structural properties of the phospholipid bilayer, suggesting that both ionized and neutral states of nonsteroidal anti-inflammatory drugs must be considered to clarify their mechanisms of toxicity and to ultimately develop safer anti-inflammatory drugs.

Composite phospholipid-coated hollow mesoporous silica nanoplatform with multi-stimuli responsiveness for combined chemo-photothermal therapy

Chemo-photothermal therapy can improve the therapeutic effects of simple chemotherapy with the help of cytotoxic heat generated by photothermal therapy. In this paper, a novel nanoplatform based on hollow mesoporous silica (HMSN) was constructed, which could achieve multi-stimuli-responsive release through chemo-photothermal interaction. Cypate as a NIR photothermal agent was conjugated to the outer surface of HMSN by disulfide bonds. Due to the insoluble feature, Cypate imparted lipophilicity to the surface of HMSN, thereby promoting the strong encapsulation of complex phospholipid layer by hydrophobic interaction. The phospholipid layer hindered the premature release of the model drug doxorubicin (DOX), prolonged the circulation time in vivo, and improved the biocompatibility and stability in physiological environment. Under glutathione, acidic conditions and NIR irradiation, the release of DOX was significantly accelerated, indicating that DOX/HMSN-CyL exhibited redox/pH/NIR multi-stimuli in response to drug release. Cytotoxicity experiments have proved that combination therapy induced the maximum levels of cell killing. Furthermore, combination index of DOX/HMSN-CyL was 0.26, demonstrating the chemo-photothermal synergetic therapy. Multicellular tumor spheroid experiments were also performed, and the same trend was showed. In summary, this novel nanoplatform has broad application prospects as a drug delivery system for combination therapy.

Phospholipid modified glassy carbon electrode for determination of chili peppers pungency by ex-situ extraction voltammetry

Objective determination of chili peppers pungency, for which capsaicinoids (CPDs), predominantly capsaicin (CA) and dihydrocapsaicin (DHC) are responsible, belongs to frequently solved tasks in food and medicinal analysis. In this manuscript, application of ex-situ extractive stripping voltammetry (ExSV) utilizing a phospholipid modified glassy carbon electrode is described.The obtained analytical parameters, e.g., linear dynamic range from 3 to 60 mg L−1, limit of detection 2.1 mg L−1, proved to be fully comparable with those achieved using the direct voltammetric method on a polished glassy carbon electrode and reference HPLC/UV. Although the sensitivity of ExSV was slightly lower compared to the direct method, ExSV provided better selectivity to CPDs due to their lipophilic interactions with the phospholipid layer. Hydrophilic components of the chili pepper samples were not extracted into the phospholipid layer and therefore did not interfere. The developed method was tested on the determination of CPDs in different chili peppers: Foxta, Madras Chilli, Habanero, Carolina Reaper, Bird's eye, Bhut Jolokia, Naga Jolokia extract, and Habanero extract.Furthermore, the electrochemical reactions of CPDs in acidic aqueous-methanolic media were characterized using an electrochemical cell hyphenated with mass spectrometer and the main oxidation products were identified.

Preparation and characterisation of Fe&lt;SUB align="right"&gt;3O&lt;SUB align="right"&gt;4@SiO&lt;SUB align="right"&gt;2@MTX@Lipid nanoparticles as a controlled drug-delivery system

In this study, synthesis and characterisation of mesoporous, super magnetic silica with controlled release methotrexate ability were aimed for treatment of rheumatoid arthritis. Within this scope, magnetite nanoparticles were synthesised by coprecipitation method and surfaces of these nanoparticles were coated with mesoporous silica and phospholipid layers. FT-IR, XRD, VSM, BET, TEM, EDX and FESEM analyses were performed for characterisation. The results of FT-IR analysis show the existence of silica and lipid layers around magnetite. Fe3O4@SiO2 nanoparticles have a surface area of 576.69 m2/g, a pore size of 8.21 nm and a mesoporous structure. XRD analyses indicate that the synthesised Fe3O4 and Fe3O4@SiO2 nanoparticles have cubic spinel structures. FESEM images show that nanoparticles have spherical shape and VSM analysis indicates that nanoparticles have superparamagnetic characteristic.

Preparation and characterisation of Fe&lt;SUB align="right"&gt;3O&lt;SUB align="right"&gt;4@SiO&lt;SUB align="right"&gt;2@MTX@Lipid nanoparticles as a controlled drug-delivery system

In this study, synthesis and characterisation of mesoporous, super magnetic silica with controlled release methotrexate ability were aimed for treatment of rheumatoid arthritis. Within this scope, magnetite nanoparticles were synthesised by coprecipitation method and surfaces of these nanoparticles were coated with mesoporous silica and phospholipid layers. FT-IR, XRD, VSM, BET, TEM, EDX and FESEM analyses were performed for characterisation. The results of FT-IR analysis show the existence of silica and lipid layers around magnetite. Fe3O4@SiO2 nanoparticles have a surface area of 576.69 m2/g, a pore size of 8.21 nm and a mesoporous structure. XRD analyses indicate that the synthesised Fe3O4 and Fe3O4@SiO2 nanoparticles have cubic spinel structures. FESEM images show that nanoparticles have spherical shape and VSM analysis indicates that nanoparticles have superparamagnetic characteristic.

Lipid Droplets in Cancer.

Lipid droplets have a unique structure among organelles consisting of a dense hydrophobic core of neutral lipids surrounded by a single layer of phospholipids decorated with various proteins. Often labeled merely as passive fat storage repositories, they in fact have a remarkably dynamic life cycle. Being formed within the endoplasmic reticulum membrane, lipid droplets rapidly grow, shrink, traverse the cytosol, and engage in contacts with other organelles to exchange proteins and lipids. Their lipid and protein composition changes dynamically in response to cellular states and nutrient availability. Remarkably, their biogenesis is induced when cells experience various forms of nutrient, energy, and redox imbalances, including lipid excess and complete nutrient deprivation. Cancer cells are continuously exposed to nutrient and oxygen fluctuations and have the capacity to switch between alternative nutrient acquisition and metabolic pathways in order to strive even during severe stress. Their supply of lipids is ensured by a series of nutrient uptake and scavenging mechanisms, upregulation of de novo lipid synthesis, repurposing of their structural lipids via enzymatic remodeling, or lipid recycling through autophagy. Importantly, most of these pathways of lipid acquisition converge at lipid droplets, which combine different lipid fluxes and control their usage based on specific cellular needs. It is thus not surprising that lipid droplet breakdown is an elaborately regulated process that occurs via a complex interplay of neutral lipases and autophagic degradation. Cancer cells employ lipid droplets to ensure energy production and redox balance, modulate autophagy, drive membrane synthesis, and control its composition, thereby minimizing stress and fostering tumor progression. As regulators of (poly)unsaturated fatty acid trafficking, lipid droplets are also emerging as modulators of lipid peroxidation and sensitivity to ferroptosis. Clearly, dysregulated lipid droplet turnover may also be detrimental to cancer cells, which should provide potential therapeutic opportunities in the future. In this review, we explore how lipid droplets consolidate lipid acquisition and trafficking pathways in order to match lipid supply with the requirements for cancer cell survival, growth, and metastasis.

Effects of ochratoxin A on membrane phospholipids of the intestine of broiler chickens, practical consequences

Ochratoxin A (OTA) is a mycotoxin produced by various species of Aspergillus and Penicillium. Ochratoxin A was classified as a group 2B carcinogen and is one of the major intestinal pathogenic mycotoxins. One of the most frequent modes of intoxication is consumption of contaminated food with mycotoxins. Feed represents the major cost and has a direct impact on the economical viability of broiler’s production system, since it must contain the necessary elements that allow the animal to express the maximum genetic potential while providing its nutritional requirements. Thus, the animal has to digest the feed and absorb its nutrients, which is in direct correlation with the gastrointestinal tract, especially the small intestine and the development of the mucosal surface area. Once ingested, OTA is absorbed by passive diffusion, mainly the jejunum. Ochratoxin A’s presence affects lipid membranes and could lead to the degradation of their normal structure and functionality. All of these effects contribute to the development of malabsorption. It was very interesting to study the effect of OTA on the layer of phospholipids of the bowel. The experimental group received OTA (0.05 to mg/kg BW) through an intra-peritoneal injection, every other day for 21 days. We noted that feed conversion ratio and average daily gain were reduced. Histological studies showed important alterations at the level of the mucosal membrane of the intestine (villosities, crypts) following intra-peritoneal administration of the mycotoxin. Thinning and enlargement at the base of the villosities, hyperplasia and crypts in irregular forms, blunting and denudation were observed through the examination of intestinal morphology. Biochemical studies, such as total lipid and phospholipid compositions, allowed us to have more detailed results. All identified mucosal phospholipids were modified, particularly the phosphatidylcholine (PC) and the phosphatidylethanolamine (PE) in the jejunum mucosa. In fact, there was a decrease by 55.81% for PC, 56.66% for PE, while a significant increase by 32.91% was noted for phosphatidylserine in the jejunum. It was very interesting to study the effect of OTA on the phospholipids layer of the bowel, as the mucous membrane of the small intestine represents the main site of absorption and transformation of nutriments. To avoid such disturbances and prevent the effects of the OTA, precautions must be taken to inhibit mold growth at the level of the feed manufactory units. Phosphatidylcholine and PE administrations may represent an option that could allow reestablishment of phospholipid equilibrium in the intestine.

Cutaneous T-Cell Lymphoma (CTCL) Cell Line-Derived Extracellular Vesicles Contain HERV-W-Encoded Fusogenic Syncytin-1

Cutaneous T-Cell Lymphoma (CTCL) Cell Line-Derived Extracellular Vesicles Contain HERV-W-Encoded Fusogenic Syncytin-1

Self-assembled liposome from core-sheath chitosan-based fibres for buccal delivery of carvedilol: formulation, characterization and in vitro and ex vivo buccal absorption.

A novel drug delivery system based on self-assembled liposome from core-sheath nanofibres for buccal delivery of Carvedilol (Car) was explored. The Car-loaded PVP/PC (phospholipids) layer was coated with chitosan-PVA (CS-PVA) or CS-PVP to increase retention period in the mouth. SEM, confocal laser scanning microscopy (CLSM), XRD and Fourier transform infrared spectroscopy were applied to characterize fibre diameter and drug state. Appearance, particle size and encapsulation efficiency of self-assembled liposome were investigated by transmission electron microscopy (TEM) and Zeta-sizer Nano. The dissolution test and permeation tests across porcine buccal mucosa and TR146 cell model also were run. Confocal laser scanning microscopy and XRD confirmed the core-sheath structure of coaxial fibre and non-crystalline form of Car, separately. TEM demonstrated the sphere morphology of self-assembled liposome from spun fibres after contacting water. The dissolution test implied the ratio of PC to Car had a huge impact on drug release. The permeation tests across porcine buccal mucosa and TR146 cell model showed similar result, namely our formulation having a better permeation performance than Car suspension. The indirect toxicity against TR146 cells presented 5mg/ml (or lower) of fibre extraction was safe for cells. These researches exhibited this drug delivery system was promising and advantageous for Car buccal delivery.

Myelin basic protein (MBP) charge variants show different sphingomyelin-mediated interactions with myelin-like lipid monolayers

Multiple sclerosis (MS) is correlated with increased deimination of myelin basic protein (MBP) in the central nervous system. Here, the interaction of MBP C1 (charge: +19) and MBP C8 (charge: +13) with the major lipids of the cytoplasmic side of the oligodendrocyte membrane is analysed using monolayer adsorption experiments and epifluorescence microscopy. Our findings show that the electrostatic attraction between the positively charged proteins and negatively charged lipids in the myelin-like monolayers competes with the incorporation of MBP into regions directly bordering cholesterol-rich domains. The latter is favoured to avoid additional lipid condensation and reduction in fluidity of the phospholipid layer. We find that MBP C1 does not incorporate at the cholesterol-rich domains if sphingomyelin (SM) is absent from the lipid composition. In contrast, MBP C8 is still incorporated near cholesterol-enriched regions without SM. Thus, the highly charged C1 variant needs a specific interaction with SM, whereas for C8 the incorporation at the cholesterol-rich regions is ensured due to its reduced net positive charge. This phenomenon may be relevant for the correlation of higher amounts of MBP C8 in brains of adult MS patients and healthy children, in which the amount of SM is reduced compared to healthy adults.

Preparation And Antibacterial Effects Of Carboxymethyl Chitosan-Modified Photo-Responsive Camellia Sapogenin Derivative Cationic Liposomes.

BackgroundBacterial resistance to antibiotics is a persistent and intractable problem. The sapogenin isolated from the seeds of Camellia oleifera can inhibit antibiotic-resistant bacteria after structural modification.PurposeThis study aims to improve sapogenin's antibacterial activity and avoid bacterial resistance based on nano-preparation with photo responsiveness.MethodsThe liposome shell material of carboxymethyl chitosan-phosphatidyl ethanolamine (CMC-PE) was prepared using amidation reaction, and photo-responsive cationic (PCC) liposomes containing Camellia sapogenin derivative (CSD) and photosensitizer pheophorbide-a were prepared by film dispersion method. Encapsulation efficiency, drug loading, zeta potential, particle size distribution, morphology and stability of the PCC liposomes were determined by HPLC, particle size analyzer, transmission electron microscopy (TEM) and fluorescence microscopy. Photo-responsive release of CSD in the PCC liposomes was determined by laser (0.5 mW/cm2) at 665 nm. Antibacterial activity of the PCC liposomes with or without irradiation was analyzed by MIC50, MBC, MBIC50, and bacterial morphology to evaluate the antibacterial effects on amoxicillin resistant Escherichia coli and Staphylococcus aureus.ResultsSize distribution, zeta potential, encapsulation efficiency and drug loading of the PCC liposomes were 189.23 ± 2.12 nm, 18.80 ± 1.57 mV, 83.52 ± 1.53% and 2.83 ± 0.05%, respectively. The PCC liposomes had higher storage stability and gastrointestinal stability, and no obvious hemolytic toxicity to rabbit red blood cells and no cytotoxicity after incubation with Hela cells. The photosensitizer pheophorbide-a was uniformly dispersed in the phospholipid layer of the PCC liposomes and increased the CSD release after irradiation. The PCC liposomes could bind to bacteria and impaired their morphology and structure, and had significant bactericidal effect on amoxicillin resistant E. coli and S. aureus.ConclusionThe photo-responsive PCC liposomes are efficient antibacterial agents for avoidance of bacterial resistance against antibiotics.

Lead Halide Perovskite Nanocrystals-Phospholipid Micelles and Their Biological Applications: Multiplex Cellular Imaging and in Vitro Tumor Targeting.

Lead halide perovskite nanocrystals (NCs) are promising optical materials in many fields. However, their poor moisture stability, significant toxicity, and difficulty to be further functionalized greatly hinder their applications in bioimaging. Here, a universal strategy is demonstrated by simply encapsulating CsPbX3 (X = Cl, Br, I) NCs into phospholipids to achieve CsPbX3-phospholipid micelles (CsPbX3@phospholipid) as probes for multiplex encoding cellular imaging or tumor-targeted imaging. The layer of phospholipids endows CsPbX3 NCs with superior water-resistant characteristics, the ability to be further biofunctionalized, and greatly improved biocompatibility. The CsPbX3@phospholipid micelles exhibited strong luminescence with narrow fwhm in water for more than four months. Specifically, even after being modified with folic acid, the bright fluorescence of the micelles was well retained, which were employed for the targeting of Hela cells. Finally, the greatly reduced toxicity of the CsPbX3@phospholipid micelles was verified using HeLa cells and zebrafish as in vitro and in vivo models, respectively.

Kinetics and localisation of haemin-induced lipoprotein oxidation

Haemin (iron (III)-protoporphyrin IX) is a degradation product of haemoglobin in circulating erythrocytes. Haemin may play a key oxidising agent for lipoprotein oxidation in patients with haemolytic anaemia. In this study, kinetic changes in chemical composition and target sites of haemin-induced LDL and HDL oxidation were investigated. Haemin initially induced the loss of α-tocopherol, followed by accumulation of lipid hydroperoxide (LP) and alteration of core lipid fluidity. The absence of LP in HDL was explained by the antioxidant activity of PON in addition to α-tocopherol. The target site of haemin was evaluated by ESR spin labelling with 5- and 16-doxyl steric acids. In the presence of t-BuOOH and haemin, ESR signal decay of the doxyl moiety demonstrated the initiation phase and the propagation phase of lipid peroxidation. The results of the lag time and the rate of signal decay indicated that haemin is located near the 16th carbon atom of the fatty acid chain in the phospholipid layer. The analyses of motion parameters, order parameter (S) of 5-DS and rotational correlation time (τ) of 16-DS, supported the observation that the lipid properties changed near the hydrophobic region rather than at the surface region of lipoproteins. Moreover, ESR spin labelling demonstrated that haemin molecules but not iron ions caused lipoprotein oxidation. In conclusion, haemin is a potent inducer of lipoprotein oxidation, and the target site for this oxidation is near the hydrophobic core of the lipoprotein leading to the loss of antioxidant activities and changes in lipid composition and physical properties.

Lung carcinoma therapy using epidermal growth factor receptor‑targeted lipid polymeric nanoparticles co‑loaded with cisplatin and doxorubicin

The rate of lung cancer in tuberculosis (TB) patients is 7to30%higher than that in healthy individuals. Conventional chemotherapy of lung cancer shows limited efficiency due to poor tumor tissue drug accumulation and nonspecific cytotoxicity. Epidermal growth factor receptor (EGFR) is a promising target, which is overexpressed in lung carcinomas. In the present study, EGFR‑targeted nanoparticles were constructed and co‑delivered cisplatin (CDDP) and doxorubicin (DOX) for lung cancer therapy. In the present research, EGF‑PEG‑DSPE was synthesized. Then, EGFR‑targeted lipid polymeric nanoparticles (LPNs) were fabricated, which consisted of a CDDP‑loaded hybrophobic polymeric core, a DOX‑loaded phospholipid layer, and an outer layer of EGF‑PEG‑DSPE ligand. The particle size, ζ potential, stability, release behavior of LPNs were characterized. The antitumor ability of LPNs were assessed invitro and invivo. EGFR‑targeted LPNs loaded with CDDP and DOX (EGFC/DLPNs) had a size of 141.6nm, and could encapsulate over 80%of feed drugs. Dual drug‑loaded LPNs showed synergistic effects with a combination index (CI) of 0.57. EGFC/DLPNs showed the smallest tumor volume (253mm3), with a tumor inhibition ratio of 74.5%. In summary, EGFC/DLPNs were stable and released the drugs in a sustained manner. Invitro and invivo studies revealed that EGFC/DLPNs exhibited improved anticancer activity along with lower toxicity. These results indicated the best efficiency of EGFC/DLPNs for lung carcinoma therapy.

Enzyme‐mediated assembly of chimeric membrane proteins at phospholipid bilayers

Integral membrane proteins (IMPs) pose a challenge to study in vitro, as it is difficult to reproduce the membrane‐imbedded context of their native state. In this study, we developed a generalized strategy for the assembly of chimeric IMPs within a phospholipid bilayer surface based on a two‐step process that first imbeds the insoluble domain of the IMP into a phospholipid layer and then ligates the soluble part of the IMP to the imbedded portion under mild biochemical conditions using a mutant sortase A enzyme. The approach is demonstrated using the transmembrane domain of epidermal growth factor receptor (EGFR) and the soluble extracellular loop of the B‐lymphocyte antigen CD20 protein in a POPC tethered bilayer membrane (tBLM). The conditions of the enzymatic reaction were optimized for peptide ligation at the tBLM surface and the role of Ca2+ ions in ligation efficiency examined. Additionally, binding of the CD20/EGFR chimera in the context of a membrane environment by the rituximab antibody was measured to assess functionality.

Application to Nano Drug Carrier Using Polymer Nano-Film Synthesized on Self-Assembled Phospholipid Layer Fabricated by Plasma-Assisted Method

Application to Nano Drug Carrier Using Polymer Nano-Film Synthesized on Self-Assembled Phospholipid Layer Fabricated by Plasma-Assisted Method

A New Class of Blue‐LED‐Excitable NIR‐II Luminescent Nanoprobes Based on Lanthanide‐Doped CaS Nanoparticles

AbstractLanthanide (Ln3+)‐doped luminescent nanoparticles (NPs) with emission in the second near‐infrared (NIR‐II) biological window have shown great promise but their applications are currently limited by the low absorption efficiency of Ln3+ owing to the parity‐forbidden 4f→4f electronic transition. Herein, we developed a strategy for the controlled synthesis of a new class of NIR‐II luminescent nanoprobes based on Ce3+/Er3+ and Ce3+/Nd3+ co‐doped CaS NPs, which can be effectively excited by using a low‐cost blue light‐emitting diode chip. Through sensitization by the allowed 4f→5d transition of Ce3+, intense NIR‐II luminescence from Er3+ and Nd3+ with quantum yields of 9.3 % and 7.7 % was achieved, respectively. By coating them with a layer of amphiphilic phospholipids, these NPs exhibit excellent stability in water and can be exploited as sensitive NIR‐II luminescent nanoprobes for the accurate detection of an important disease biomarker, xanthine, with a detection limit of 32.0 nm.

A New Class of Blue-LED-Excitable NIR-II Luminescent Nanoprobes Based on Lanthanide-Doped CaS Nanoparticles.

Lanthanide (Ln3+ )-doped luminescent nanoparticles (NPs) with emission in the second near-infrared (NIR-II) biological window have shown great promise but their applications are currently limited by the low absorption efficiency of Ln3+ owing to the parity-forbidden 4f→4f electronic transition. Herein, we developed a strategy for the controlled synthesis of a new class of NIR-II luminescent nanoprobes based on Ce3+ /Er3+ and Ce3+ /Nd3+ co-doped CaS NPs, which can be effectively excited by using a low-cost blue light-emitting diode chip. Through sensitization by the allowed 4f→5d transition of Ce3+ , intense NIR-II luminescence from Er3+ and Nd3+ with quantum yields of 9.3 % and 7.7 % was achieved, respectively. By coating them with a layer of amphiphilic phospholipids, these NPs exhibit excellent stability in water and can be exploited as sensitive NIR-II luminescent nanoprobes for the accurate detection of an important disease biomarker, xanthine, with a detection limit of 32.0 nm.

Change in interfacial properties of milk fat globules by homogenization and thermal processing plays a key role in their in vitro gastrointestinal digestion

The effects of homogenization, homogenization plus thermal processing including high temperature short time (HHTST) or ultra-high temperature (HUHT) treatment on digestion and interfacial properties of milk fat globules during simulated gastrointestinal digestion were investigated. Compared to raw milk fat globules, homogenization and thermal processing increased the initial digestion rate of milk fat globules. Homogenization increased the release of middle- and long-chain fatty acids, HHTST increased the release of unsaturated fatty acids, and HUHT increased the release of all types of fatty acids under gastrointestinal digestion. After homogenization, milk proteins (caseins and whey proteins) increased but glycosylated molecules decreased, both of which were at the surface of milk fat globules. The amount of glycosylated molecules at the surface of HHTST milk fat globules and the amount of denatured milk proteins at the surface of HUHT milk fat globules were higher than those of homogenized milk fat globules. During gastrointestinal digestion, fat globules in HHTST milk possessed higher amount of glycosylated molecules and more integrated phospholipid layers, and HUHT milk fat globules had more filamentous phospholipid layers, and less integrated phospholipid layers and glycosylated molecules than those of homogenized milk fat globules. Therefore, the changes in composition and microstructure of glycosylated molecules and phospholipid layers at the surface of milk fat globules induced by homogenization and thermal processing might contribute to the digestion difference of milk fat globules.