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Unique Distribution of Diacyl-, Alkylacyl-, and Alkenylacyl-Phosphatidylcholine Species Visualized in Pork Chop Tissues by Matrix-Assisted Laser Desorption/Ionizationa??Mass Spectrometry Imaging
摘要： Phosphatidylcholine (PC) is the major phospholipid in meat and in?uences meat qualities, such as healthiness. PC is classi?ed into three groups based on the bond at the sn-1 position: Diacyl, alkylacyl, and alkenylacyl. To investigate their composition and distribution in pork tissues, including longissimus thoracis et lumborum (loin) spinalis muscles, intermuscular fat, and transparent tissues, we performed matrix-assisted laser desorption/ionization–mass spectrometry imaging (MALDI–MSI). Eleven diacyl-, seven alkylacyl-, and six alkenylacyl-PCs were identi?ed using liquid chromatography (LC)-tandem MS (MS/MS) analysis. Despite many alkylacyl- and alkenylacyl-PC species sharing identical m/z values, we were able to visualize these PC species using MALDI–MSI. Diacyl- and alkylacyl- and/or alkenylacyl-PC species showed unique distribution patterns in the tissues, suggesting that their distribution patterns were dependent on their fatty acid compositions. PCs are a major dietary source of choline in meat, and the amount was signi?cantly higher in the muscle tissues. Consumption of choline mitigates age-related memory decline and neurodegenerative diseases; therefore, the consumption of pork muscle tissues could help to mitigate these diseases. These results support the use of MALDI–MSI analysis for assessing the association between PC species and the quality parameters of meat.
关键词： mass spectrometry imaging (MSI),lipid distribution,phosphatidylcholines,liquid chromatography-tandem mass spectrometry (LC-MS/MS),pork,matrix-assisted laser desorption/ionization (MALDI)
更新于2025-09-23 15:19:57
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An Expandable Mechanopharmaceutical Device (3): a Versatile Raman Spectral Cytometry Approach to Study the Drug Cargo Capacity of Individual Macrophages
摘要： Purpose To improve cytometric phenotyping abilities and better understand cell populations with high interindividual variability, a novel Raman-based microanalysis was developed to characterize macrophages on the basis of chemical composition, specifically to measure and characterize intracellular drug distribution and phase separation in relation to endogenous cellular biomolecules. Methods The microanalysis was developed for the commercially-available WiTec alpha300R confocal Raman microscope. Alveolar macrophages were isolated and incubated in the presence of pharmaceutical compounds nilotinib, chloroquine, or etravirine. A Raman data processing algorithm was specifically developed to acquire the Raman signals emitted from single-cells and calculate the signal contributions from each of the major molecular components present in cell samples. Results Our methodology enabled analysis of the most abundant biochemicals present in typical eukaryotic cells and clearly identified Bfoamy^ lipid-laden macrophages throughout cell populations, indicating feasibility for cellular lipid content analysis in the context of different diseases. Single-cell imaging revealed differences in intracellular distribution behavior for each drug; nilotinib underwent phase separation and self-aggregation while chloroquine and etravirine accumulated primarily via lipid partitioning. Conclusions This methodology establishes a versatile cytometric analysis of drug cargo loading in macrophages requiring small numbers of cells with foreseeable applications in toxicology, disease pathology, and drug discovery.
关键词： lipid-laden foamy macrophages,intracellular drug bioaccumulation,single-cell chemical imaging,confocal Raman microscopy,pulmonary alveolar macrophages
更新于2025-09-23 15:19:57
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Formation of lipid bilayers on the pore walls of macroporous silicon
摘要： Electron paramagnetic resonance (EPR) spectroscopy was used to study the pore filling of macroporous silicon with lipid vesicles (liposomes), added with a spin label. Different EPR spectra were obtained with the magnetic field parallel and perpendicular to the macroporous silicon sample surface. These spectra could be well simulated with an admixture of the isotropic spectrum of liposomes, plus a simulated spectrum corresponding to a cylindrical distribution of lipid bilayers. This means that a portion of the liposomes were disrupted, and supported lipid bilayers were formed covering the inner surface of the pores. Diverse protocols can be explored in order to optimize the lipid covering of the pore walls, and to achieve an adequate lipid hydration. This system can be used as a platform to study lipid phase transitions in a confined environment, and to characterize membrane proteins.
关键词： Liposomes,Electron paramagnetic resonance/electron spin resonance,Supported lipid bilayers,Porous silicon,Spin labels
更新于2025-09-19 17:15:36
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Low Intensity Light-Induced Paclitaxel Release from Lipid Based Nano-delivery Systems
摘要： Light-induced drug release has been explored as a strategy for externally modulating the release of drug from delivery systems. This study reports the development of a solid lipid nanoparticulate system (SLN) for paclitaxel (PTX), where photosensitizer-mediated oxidation of lipids was used as a mechanism for controlling the drug release. Low-intensity (23 mW/cm2) near-infrared (around 730 nm) illumination was externally applied as the light source. Paclitaxel release was less than 10% within 4 hrs from these SLN and was 8-fold higher after application of light at time zero. The other advantages of this approach include the use of ascorbic acid as an antioxidant for enhancing the release and storage stability of the delivery system. Antioxidant like ascorbic acid in the SLN decrease the degradation of lipid by 8-fold within 4 months of storage. Presence of ascorbic acid and light illumination of SLN containing PTX further decreased the IC50 by 2 times in A549 cells. The uniqueness of this approach allows the possibility of external modulation to achieve pulsatile release from the delivery system. The light used in the NIR spectral range of 700-850 nm, which has the greatest tissue penetration ability, with a low intensity will be safe for normal tissues.
关键词： near-infrared photosensitizer,anticancer,lipid nanoparticles,hydrophobic drugs,controlled release,low-intensity light
更新于2025-09-19 17:15:36
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Lipid Emulsion–Based OCT Angiography for Ex Vivo Imaging of the Aqueous Outflow Tract
摘要： PURPOSE. Contrast agents applicable for optical coherence tomography (OCT) imaging are rare. The intrascleral aqueous drainage system would be a potential application for a contrast agent, because the aqueous veins are of small diameter and located deep inside the highly scattering sclera. We tested lipid emulsions (LEs) as candidate OCT contrast agents in vitro and ex vivo, including milk and the anesthetic substance Propofol. METHODS. Commercial OCT and OCT angiography (OCTA) devices were used. Maximum reflectivity and signal transmission of LE were determined in tube phantoms. Absorption spectra and light scattering was analyzed. The anterior chamber of enucleated porcine eyes was perfused with LEs, and OCTA imaging of the LEs drained via the aqueous outflow tract was performed. RESULTS. All LEs showed a significantly higher reflectivity than water (P < 0.001). Higher milk lipid content was positively correlated with maximum reflectivity and negatively with signal transmission. Propofol exhibited the best overall performance. Due to a high degree of signal fluctuation, OCTA could be applied for detection of LE. Compared with blood, the OCTA signal of Propofol was significantly stronger (P ? 0.001). As a proof of concept, time-resolved aqueous angiography of porcine eyes was performed. The three-dimensional (3D) structure and dynamics of the aqueous outflow were significantly different from humans. CONCLUSIONS. LEs induced a strong signal in OCT and OCTA. LE-based OCTA allowed the ability to obtain time-resolved 3D datasets of aqueous outflow. Possible interactions of LE with inner eye's structures need to be further investigated before in vivo application.
关键词： lipid emulsion,propofol,optical coherence tomography angiography,aqueous flow
更新于2025-09-19 17:15:36
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High-Resolution Label-Free Studies of Molecular Distribution and Orientation in Ultrathin, Multicomponent Model Membranes with Infrared Nano-Spectroscopy AFM-IR
摘要： Biological membranes are undoubtedly very interesting systems. Unfortunately, their analysis is very complicated and therefore simplified artificial models, like Langmuir monolayers, are frequently applied. In this work a novel method of label-free monomolecular films analysis based on infrared nano-spectroscopy (AFM-IR) is presented. In order to verify applicability of this approach well-defined referential system of sphingomyelin (SM), cholesterol (Chol) and cyclosporin A (CsA) is applied. AFM-IR method allows to directly and chemoselectively map the distribution of components in model lipid membranes. Additionally the orientation of Chol and SM molecules in the monolayer is determined by application of two perpendicular infrared laser polarizations. This paper is the first report of using AFM-IR to analyze LB films with extremely high sensitivity.
关键词： phase separation,lipid rafts,Langmuir-Blodgett films,Cyclosporin A,AFM-IR
更新于2025-09-19 17:15:36
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Incorporation in Lipid Microparticles of Acid Red 87, a Colourant Used in Tattoo Inks: Effect on Photodegradation Under Simulated Sunlight and Laser Radiation
摘要： Tattoo colourants decompose under solar radiation and when exposed to laser light for their removal, leading to the accumulation in the dermis of toxic products. Aim of this study was to develop lipid microparticles (LMs) loaded with the colourant, Acid Red 87 (C.I. 45380) used in tattoo inks, and to investigate the effect of this system on the photostability of the colourant under simulated sunlight or laser irradiation. LMs loaded with C.I. 45380 were prepared by melt emulsification using tristearin and phosphatidylcholine as excipients. They were characterized by optical microscopy, laser diffraction, X-ray diffraction and release studies. Free C.I. 45380 and the colourant-loaded LMs were irradiated with a solar simulator or a Q-switched laser. Irradiation with a solar simulator demonstrated that photodecomposition of C.I. 45380 was markedly reduced by incorporation of the dye in the LMs, from 20.5 ± 4.6% to 1.3 ± 1.8%. Conversely, the laser-induced degradation of the colourant (30.1 ± 6.6%) was not significantly influenced by encapsulation in the LMs (the encapsulated C.I. 45380 loss was 27.4 ± 5.5%). Incorporation of C.I. 45380 in lipid microparticles enhances the photostability under sunlight of tattoo inks containing this colourant, without affecting its laser-induced degradation and hence laser removal efficiency.
关键词： photodegradation,Acid Red 87,tattoo colourants,laser radiation,lipid microparticles
更新于2025-09-19 17:13:59
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Analysis on FM-to-AM conversion of SSD beam induced by etalon effect in a high-power laser system
摘要： Malondialdehyde (MDA) was selected to represent a secondary by-product of lipid peroxidation during rice ageing. This study aimed to investigate the effects of MDA modification on the structural characteristics of rice protein. The results showed that as MDA concentration increased, rice protein carbonyl and disulphide groups increased, but sulphydryl content decreased. The blue shift of maximum fluorescence peak, the decrease of rice protein intrinsic fluorescence intensity and the reduction of surface hydrophobicity indicated the formation of protein aggregates caused by MDA oxidative modification. The results of molecular weight distribution and particle size distribution showed that MDA modification resulted in the formation of soluble protein aggregates, and the decrease of rice protein solubility indicated that insoluble protein aggregates were formed. Results of protein electrophoresis showed that MDA modification contributed to rice protein aggregation via non-disulphide covalent bonds. The results showed that rice protein gradually aggregated with increasing MDA concentration.
关键词： Aggregation,rice protein,protein oxidation,lipid peroxidation,rice ageing,malondialdehyde
更新于2025-09-19 17:13:59
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Generation of transgenic zebrafish with 2 populations of RFP- and GFP-labeled thrombocytes: analysis of their lipids
摘要： Zebrafish thrombocytes are similar to mammalian platelets. Mammals have young platelets (also called reticulated platelets) and mature platelets. Likewise, zebrafish have 2 populations of thrombocytes; one is DiI-C18 (DiI)+ (DP), and the other is DiI? (DN). However, the mechanism of selective thrombocyte labeling by DiI is unknown. Furthermore, there is no transgenic zebrafish line where DP and DN thrombocytes are differentially labeled with fluorescent proteins. In this study, we found that Glo fish, in which the myosin light chain 2 promoter drives the rfp gene, have a population of thrombocytes that are red fluorescent protein (RFP) labeled. We also generated transgenic GloFli fish in which DP and DN thrombocytes are labeled with RFP and green fluorescent protein (GFP), respectively. Single-cell lipid analysis showed a twofold increase in phosphatidylethanolamine (PE) and a twofold decrease in phosphatidylcholine (PC) in RFP+ thrombocytes compared with GFP+ thrombocytes, suggesting that lipid composition may be important for DiI differential labeling. Therefore, we tested liposomes prepared with different ratios of PC and PE and observed that liposomes prepared with higher amounts of PE favor DiI labeling, whereas the PC concentration had a modest effect. In liposomes prepared using only PE or PC, increased concentrations of PE resulted in increased DiI binding. These results suggest that because RFP+ thrombocytes have higher PE concentrations, DiI may bind to them efficiently, thus explaining the selective labeling of thrombocytes by DiI. This work also provides GloFli fish that should be useful in understanding the mechanism of thrombocyte maturation.
关键词： lipid composition,RFP,phosphatidylcholine,GFP,DiI,phosphatidylethanolamine,thrombocytes,zebrafish
更新于2025-09-19 17:13:59
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Lipid Droplet Composition Varies Based on Medaka Fish Eggs Development as Revealed by NIR-, MIR-, and Raman Imaging
摘要： In fertilized fish eggs, lipids are an energy reservoir for the embryo development and substrate for organogenesis. They occur in the cytoplasmic area and form lipid droplets (LDs), but also the yolk egg is composed of lipids and proteins. Insight on the LD formation and distribution and their interactions with other cellular organelles could provide information about the role based on the egg development. For non-destructive, macro-scale visualization of biochemical components of fish eggs, such as lipids proteins and water, near-infrared (NIR) imaging is the method of choice. Mid-infrared (MIR) and Raman spectroscopy imaging were used to provide details on chemical composition of LDs and other egg organelles. NIR imaging illustrated main compartments of the egg including membrane, LDs, yolk, relative protein, and lipid content in well-localized egg structures and their interactions with water molecules. In the yolk, a co-existence of lipids and proteins with carotenoids and carbohydrates was detected by Raman spectroscopy. Results showed a prominent decrease of unsaturated fatty acids, phospholipids, and triglycerides/cholesteryl esters content in the eggs due to the embryo development. An opposite trend of changes was observed by MIR spectroscopy for the glycogen, suggesting that consumption of lipids occurred with production of this carbohydrate. The comprehensive vibrational spectroscopic analysis based on NIR, MIR, and Raman imaging is a unique tool in studying in situ dynamic biological processes.
关键词： near- and mid-infrared spectroscopic imaging,Raman spectroscopic imaging,lipids,lipid bodies,fertilized egg
更新于2025-09-16 10:30:52