​Apolipoproteins are a diverse class of lipid-binding proteins that regulate lipid transport, metabolism, and cellular signaling. Major families, including ApoA, ApoB, ApoC, ApoD, ApoE, ApoH, ApoJ (clusterin), ApoL, and ApoM, serve as structural components of lipoproteins and modulators of lipid-associated pathways. Apolipoprotein E (ApoE) is critically involved in the pathogenesis of Alzheimer’s disease and exists in three major isoforms (ApoE2, ApoE3, and ApoE4) which differentially influence the disease risk and progression. ApoE3 exhibits relatively stable lipid interactions and supports more effective amyloid clearance compared to pathogenic isoforms, thereby reducing neurotoxicity. Since ApoE3 drives receptor-mediated interactions, ApoE3:POPC:cholesterol nanoparticles provide a physiologically relevant and tunable platform to study receptor-mediated lipid efflux and cellular lipid trafficking. Here we demonstrate how ApoE3-POPC and ApoE3-POPC-Cholesterol nanoparticles enhance the efflux of fluorescently tagged saturated fatty acids and cholesterol.

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To cite this poster: Khatri, Y., Bae, J.-Y., Anders, A., et al. ApoE3 Lipid Particles: Assembly, Dynamics, and Biological Roles. Poster presented at: 2026 Lipids@Wayne Research Symposium; May 5 – 6, 2026; Detroit, MI.

​We evaluated the accuracy of lipid quantitation in human plasma by LC-MS using single-point or multipoint calibration curves with authentic or surrogate standards.

Highlights: 

​Key Features

To cite this application note: Kwiatkowski, M.J., Goodwin, S.K., DeLoy, S.L., et al. Characterization of human plasma as a reference material for lipid analysis using LC-MS. Application Note, Cayman Chemical Company (2025).

Untargeted lipidomics uses MS to analyze hundreds of molecular species in biological samples. Single-point calibration based on the known amounts of internal standards is used in many studies, especially those using shotgun (i.e., without chromatography) MS analysis, but questions remain about the accuracy of single-point calibration compared to the traditional interpolation in multipoint calibration curves, as well as its suitability in LC-MS studies, where internal standards may not coelute with most of the endogenous analytes.

The objective of this study is to assess the accuracy of quantitation of lipids in human plasma by LC-MS using either single-point or multipoint calibration curves with authentic or surrogate lipid standards, using a new preparation of human reference plasma and methods validated by comparison with published values from the NIST SRM 1950 Metabolites in Human Plasma material.

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To cite this poster: Kennedy, P.D., Palagama, D.S.W., Kwiatkowski, M.J., et al. Evaluation of the quantification capabilities of untargeted lipidomics approaches. Poster presented at: 73^rd Conference on Mass Spectrometry and Allied Topics; June 1-5, 2025; Baltimore, MD.

Lipids are key molecules in maintaining cellular membranes, in energy storage, cellular signaling, and many other biological processes. Mass spectrometry has become the gold standard for analyzing lipids and understanding their roles in health and disease, and well-characterized reference materials increase confidence in lipid quantitative data by validating the analytical methods employed.

The objective of this study is to characterize a preparation of human plasma as a reference for the analysis of a wide variety of lipids, using both targeted and untargeted LC-MS-based methods which are validated by comparison with the NIST SRM 1950 Metabolites in Human Plasma material.

View the reference data (.xlsx)

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To cite this poster: Kwiatkowski, M.J., Goodwin, S.K., DeLoy, S.L., et al. Characterization of human plasma as a reference material for lipid analysis using LC-MS. Poster presented at: 73^rd Conference on Mass Spectrometry and Allied Topics; June 1-5, 2025; Baltimore, MD.

​Explore fundamental mechanisms of biology, identify biomarkers, and develop new therapies with high-purity lipid standards available from Cayman.

Octadecanoids, oxylipins derived from linoleic or linolenic acids, are being increasingly recognized as having important effects in biological responses. Here we show how authentic standards of several isomeric octadecanoids facilitate the establishment of LC–MS/MS method for the detection and quantitation of epoxyoctadecadienoic acids (EpODEs) and dihydroxyoctadecadienoic acids (DiHODEs) in rat plasma.

To cite this application note: DeLoy, S., Dittmer, J., LaGory, D., et al. ​​Analysis of Complex Mixtures of Octadecanoid Isomers by LC–MS/MS. Application Note, Cayman Chemical (2025).

Beyond its implications in disease, apoliporotein E (ApoE) has been implicated in the intricate process of lipid nanoparticle (LNP) uptake. Recent studies have revealed the essential role of ApoE in facilitating the cellular internalization of LNPs, providing a potential avenue for targeted drug delivery and therapeutic interventions. In this study we have expressed and purified all three ApoE isoforms and characterized their binding properties to cognate ligands by surface plasmon resonance (SPR). Furthermore, we show that Cayman-produced LNP uptake is enhanced by addition of exogenous ApoE in a cell-based assay with lung epithelial cells. 

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To cite this poster: Guerra, A.J., Muzzarelli, K.M., Gronevelt, J.P., et al. Apolipoprotein E: Purification, characterization, and lipid nanoparticle uptake enhancement. Poster presented at: PEGS Boston Summit; May 13-17, 2024. Boston, MA.

Oxylipins, produced by the oxidation of polyunsaturated fatty acids (PUFAs), are lipid mediators involved in a variety of biological mechanisms of health and disease. Octadecanoids are 18-carbon oxylipins derived from linoleic or linolenic acids, and they are increasingly recognized as having important effects in biological responses. This study shows the synthesis and characterization of twelve new standards for epoxy-octadecadienoic acids (EpODEs) and dihydroxy-octadecadienoic acids (DiHODEs) derived from α-linolenic acid (ALA) and γ-linolenic acid (GLA), which expand the availability of biochemical tools to further investigate the biological roles of octadecanoids. 

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To cite this poster: DeLoy, S., Dittmer, J., LaGory, D., et al. Synthesis and Characterization of New Octadecanoid Standards. Poster presented at: 5^th EpiLididNET Action Meeting; May 13-15, 2024. Dresden, Germany.

​Many studies have linked extracellular vesicles (EVs) to disease progression. For example, EVs from diabetic and obese mice can induce insulin resistance while EVs from healthy mice can reverse these effects. EVs are lipid bilayer nanoparticles released from cells by a variety of mechanisms. These particles are known to contain a variety of cargo, such as lipids, proteins, nucleic acids, and other metabolites that are believed to be responsible for their cell signaling activity. 

In this study, we have performed untargeted lipidomics analysis on isolated plasma EVs from healthy and diet-induced obese, prediabetic C57BL6/J mice to study potential differences in their lipid profiles.

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To cite this poster: Kennedy, P.D., Saepoo, B., Palagama, D.S.W., et al. Characterization of Extracellular Vesicle Lipids in Pre-Diabetic Mice. Poster presented at: 8th Lipidomics Forum: ILS Annual Conference; August 27-30, 2023; Vienna, Austria

Key Features

• Cell lines derived from different tissues have distinct reporter expression patterns in response to a variety of lipid nanoparticles (LNPs).
  
• Serum requirement for LNP uptake and cargo expression in vitro vary with cell type and ionizable lipid.
• Experimental design is of utmost importance in assessing the efficacy of any given LNP preparation.
  

​Listen as Julie Rumble, PhD, Director of Immunology Services at Cayman Chemical, discusses the workflow for formulation, analysis, and testing of LNPs in multiple cell types. 

Presented by Unchained Labs and Fierce Biotech. 

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We show that our Integrated Drug Discovery Platform accelerates drug design, completing hit discovery to lead optimization in less than 10 months in this work.

We identified a certain lipid-based protein target of interest implicated in various disease states including cancer and inflammation. In less than 10 months, we developed and deployed our primary and secondary biochemical and biophysical screening assays and carried out in silico screening of multiple commercial compound libraries to identify and confirm various virtual hits. We furthermore executed an iterative structure-activity relationship (SAR) program utilizing computer-aided drug design (CADD) and synthetic and medicinal chemistry to produce over 100 novel compounds targeting the lipid-based biological target. In addition to our activity-based primary screen, we used multiple biophysical methods, including thermal shift assay (TSA), surface plasmon resonance (SPR) with Biacore™ T200, and X-ray crystallography techniques.

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To cite this poster: Muzzarelli, K.M., Assar, Z., Abdel-Haq, R., et al. Discovery of novel heterocycle inhibitors: Hit to lead compound in <10 months. Poster presented at: 18^th Annual Drug Discovery Chemistry Conference; April 10-13, 2023.