Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

Pharmacology of Heparin and Related Drugs: An Update

Heparin has been used extensively as an antithrombotic and anticoagulant for close to 100 years. This anticoagulant activity is attributed mainly to the pentasaccharide sequence, which potentiates the inhibitory action of antithrombin, a major inhibitor of the coagulation cascade. More recently it has been elucidated that heparin exhibits anti-inflammatory effect via interference of the formation of neutrophil extracellular traps and this may also contribute to heparin's antithrombotic activity. This illustrates that heparin interacts with a broad range of biomolecules, exerting both anticoagulant and nonanticoagulant actions. Since our previous review, there has been an increased interest in these nonanticoagulant effects of heparin, with the beneficial role in patients infected with SARS2-coronavirus a highly topical example. This article provides an update on our previous review with more recent developments and observations made for these novel uses of heparin and an overview of the development status of heparin-based drugs. SIGNIFICANCE STATEMENT: This state-of-the-art review covers recent developments in the use of heparin and heparin-like materials as anticoagulant, now including immunothrombosis observations, and as nonanticoagulant including a role in the treatment of SARS-coronavirus and inflammatory conditions.

Saturated tetrasaccharide profile of enoxaparin. An additional piece to the heparin biosynthesis puzzle

Enoxaparin, widely used antithrombotic drug, is a polydisperse glycosaminoglycan with highly microheterogeneous structure dictated by both parent heparin heterogeneity and depolymerization conditions. While the process-related modifications of internal and terminal sequences of enoxaparin have been extensively studied, very little is known about the authentic non-reducing ends (NRE). In the present study a multi-step isolation and thorough structural elucidation by NMR and LC/MS allowed to identify 16 saturated tetramers along with 23 unsaturated ones in the complex enoxaparin tetrasaccharide fraction. Altogether the elucidated structures represent a unique enoxaparin signature, whereas the composition of saturated tetramers provides a structural readout strictly related to the biosynthesis of parent heparin NRE. In particular, both glucuronic and iduronic acids were detected at the NRE of macromolecular heparin. The tetrasaccharides bearing glucosamine at the NRE are most likely associated with the heparanase hydrolytic action. High sulfation degree and 3-O-sulfation are characteristic for both types of NRE.

Techniques for Detection of Clinical Used Heparins

Heparins and sulfated polysaccharides have been recognized as effective clinical anticoagulants for several decades. Heparins exhibit heterogeneity depending on the sources. Meanwhile, the adverse effect in the clinical uses and the adulteration of oversulfated chondroitin sulfate (OSCS) in heparins develop additional attention to analyze the purity of heparins. This review starts with the description of the classification, anticoagulant mechanism, clinical application of heparins and focuses on the existing methods of heparin analysis and detection including traditional detection methods, as well as new methods using fluorescence or gold nanomaterials as probes. The in-depth understanding of these techniques for the analysis of heparins will lay a foundation for the further development of novel methods for the detection of heparins.

Analysis of the Glycosaminoglycan Chains of Proteoglycans

Glycosaminoglycans (GAGs) are heterogeneous, negatively charged, macromolecules that are found in animal tissues. Based on the form of component sugar, GAGs have been categorized into four different families: heparin/heparan sulfate, chondroitin/dermatan sulfate, keratan sulfate, and hyaluronan. GAGs engage in biological pathway regulation through their interaction with protein ligands. Detailed structural information on GAG chains is required to further understanding of GAG-ligand interactions. However, polysaccharide sequencing has lagged behind protein and DNA sequencing due to the non-template-driven biosynthesis of glycans. In this review, we summarize recent progress in the analysis of GAG chains, specifically focusing on techniques related to mass spectroscopy (MS), including separation techniques coupled to MS, tandem MS, and bioinformatics software for MS spectrum interpretation. Progress in the use of other structural analysis tools, such as nuclear magnetic resonance (NMR) and hyphenated techniques, is included to provide a comprehensive perspective.

Quality Control of Heparin Injections: Comparison of Four Established Methods

Heparin is an anticoagulant medication that is usually injected subcutaneously. The quality of a set of commercial heparin injections from different producers was examined by NMR, IR, UV-Vis spectroscopies and potentiometric multisensor system. The type of raw material regarding heparin animal origin and producer, heparin molecular weight and activity values were derived based on the non-targeted analysis of 1H NMR fingerprints. DOSY NMR spectroscopy was additionally used to study homogeneity and additives profile. UV-Vis and IR, being cheaper than NMR, combined with multivariate statistics were successfully applied to study excipients composition as well as semi-estimation of activity values. Potentiometric multisensor measurements were found to be an important additional source of information about inorganic composition of finished heparin formulations. All investigated instrumental techniques are useful for finished heparin injections and should be selected according to availability as well as the information and confidence required for a specific sample.

Identification of blood plasma proteins using heparin-coated magnetic chitosan particles

Heparin was immobilized on magnetic chitosan particles to be used as a tool for human plasma protein identification. Chitosan was magnetized by co-precipitation with Fe²⁺/Fe³⁺ (MAG-CH). Heparin was functionalized with carbodiimide and N-hydroxysuccinimide and covalently linked to MAG-CH (MAG-CH-hep). X-ray diffraction confirmed the presence of chitosan and Fe₃O₄ in MAG-CH. This particle exhibited superparamagnetism and size between 100-300 μm. Human plasma diluted with 10 mM phosphate buffer (pH 5.5) or 50 mM Tris-HCl buffer (pH 8.5) was incubated with MAG-CH-hep, and the proteins fixed were eluted with the same buffers containing increasing concentrations of NaCl. The proteins obtained were investigated by SDS-PAGE, LC/MS, and biological activity tests (PT, aPTT, and enzymatic chromogenic assay). Inhibitors of the serpin family, prothrombin, and human albumin were identified in this study. Therefore, MAG-CH-hep can be used to purify these proteins and presents the following advantages: low-cost synthesis, magnetic separation, ion-exchange purification, and reusability.

Identification of a heparosan heptasaccharide as an effective anti-inflammatory agent by partial desulfation of low molecular weight heparin

Low molecular weight heparin (LMWH) possesses a dual function of anticoagulation and anti-inflammation. While the structures and mechanisms on its anticoagulation have been widely studied, the structural features responsible for the anti-inflammatory activity of LMWH remain to be explored. In the present study, guided by an anti-inflammation assay, a non-anticoagulant species was generated from partial desulfation of LMWH to fully retain the anti-inflammatory activity, from which five fractions were further separated and three of them were characterized by enzymatic degradation, hydrophobic labeling, C18-based HPLC and LC-MS/MS analyses. The structure-activity relationship revealed that the sulfate groups in LMWH are critical to distinguish and separate the activities of anticoagulation and anti-inflammation, leading to the identification of a synthetic heparosan-type heptasaccharide as a potent anti-inflammatory agent. The present strategy enables the simplification of complex polysaccharides to bioactive synthetic oligosaccharides for therapeutic utility.

Systematic analysis of enoxaparins from different sources with online one- and two-dimensional chromatography

Enoxaparin, one of the most important low-molecular-weight heparins (LMWHs), is widely used as a clinical anticoagulant.

Analysis of sulfates on low molecular weight heparin using mass spectrometry: structural characterization of enoxaparin

INTRODUCTION

Structural characterization of low molecular weight heparin (LMWH) is critical to meet biosimilarity standards. In this context, the review focuses on structural analysis of labile sulfates attached to the side-groups of LMWH using mass spectrometry. A comprehensive review of this topic will help readers to identify key strategies for tackling the problem related to sulfate loss. At the same time, various mass spectrometry techniques are presented to facilitate compositional analysis of LMWH, mainly enoxaparin. Areas covered: This review summarizes findings on mass spectrometry application for LMWH, including modulation of sulfates, using enzymology and sample preparation approaches. Furthermore, popular open-source software packages for automated spectral data interpretation are also discussed. Successful use of LC/MS can decipher structural composition for LMWH and help evaluate their sameness or biosimilarity with the innovator molecule. Overall, the literature has been searched using PubMed by typing various search queries such as 'enoxaparin', 'mass spectrometry', 'low molecular weight heparin', 'structural characterization', etc. Expert commentary: This section highlights clinically relevant areas that need improvement to achieve satisfactory commercialization of LMWHs. It also primarily emphasizes the advancements in instrumentation related to mass spectrometry, and discusses building automated software for data interpretation and analysis.

A method for characterising human intervertebral disc glycosaminoglycan disaccharides using liquid chromatography-mass spectrometry with multiple reaction monitoring

Intervertebral disc (IVD) degeneration results in the depletion of proteoglycans and glycosaminoglycans (GAGs), which can lead to structural and mechanical loss of IVD function, ingrowth of nociceptive nerve fibres and eventually discogenic pain. Specific GAG types as well as their disaccharide patterns can be predictive of disease and degeneration in several tissues but have not been comprehensively studied within the IVD. A highly sensitive mass spectrometry based technique with multiple reaction monitoring (MRM) was used to provide characterisation of chondroitin sulphate (CS), hyaluronic acid (HA), heparan sulphate (HS) and their disaccharide sulphation patterns across different anatomical regions of human IVDs. Principal component analysis further distinguished important regional variations and proposed potential ageing variations in GAG profiles. CS was the GAG in greatest abundance in the IVD followed by HA and HS. Principal component analysis identified clear separation of GAG profiles between nucleus pulposus and annulus fibrosus in young and old specimens. Distinct patterns of predominantly expressed disaccharides of CS and HS between young and old IVD samples, provided preliminary evidence that important alterations in disaccharides occur within IVDs during ageing. This technique offered a novel approach to identify and quantify specific GAG disaccharides in human IVDs and the data presented were the first to offer insight into the spatial distribution as well as association with ageing of GAGs and GAG disaccharide sulphation patterns across the human IVD.