Analytical challenges of glycosaminoglycans at biological interfaces

Abstract

The analysis of glycosaminoglycans (GAGs) is a challenging task due to their high structural heterogeneity, which results in diverse GAG chains with similar chemical properties. Simultaneously, it is of high importance to understand their role and behavior in biological systems. It has been known for decades now that GAGs can interact with lipid molecules and thus contribute to the onset of atherosclerosis, but their interactions at and with biological interfaces, such as the cell membrane, are yet to be revealed. Here, analytical approaches that could yield important knowledge on the GAG-cell membrane interactions as well as the synthetic and analytical advances that make their study possible are discussed. Due to recent developments in laser technology, we particularly focus on nonlinear spectroscopic methods, especially vibrational sum-frequency generation spectroscopy, which has the potential to unravel the structural complexity of heterogeneous biological interfaces in contact with GAGs, in situ and in real time. Graphical abstract

Perlecan, A Multi-Functional, Cell-Instructive, Matrix-Stabilizing Proteoglycan With Roles in Tissue Development Has Relevance to Connective Tissue Repair and Regeneration

“…It is worthwhile noting that perlecan encodes significant biological information both in its core protein and attached HS side chains. A cursory examination of the HS interactome and advances in GAG analysis methodology amply demonstrate the biodiversity and interactive capability of HS interactions at the cell surface and their potential to control cell behaviour (Gómez Toledo et al, 2021;Szekeres et al, 2021;Vallet et al, 2021). Much still needs to be learned of the complex information conveyed by the GAG glycocode and how this information translates to the cellular mechanisms that drive tissue processes during development, growth, and disease.…”

Efficient generation of few-cycle pulses beyond 10 μm from an optical parametric amplifier pumped by a 1-µm laser system

“…Chirp compensation is achieved by propagation through bulk germanium leading to 101-fs pulses (i.e., 2.9 optical cycles). Despite the low total pump pulse energy, the MIR output pulses can drive a broad range of nonlinear and/or vibrational spectroscopic applications, such as broadband vibrational sum-frequency generation spectroscopy of heterogeneous biological interfaces 26 .…”

Commercial Low Molecular Weight Heparins — Patent Ecosystem and Technology Paradigm for Quality Characterization

“…This adds to scoring the need for still more analytically sensitive, specific, and technically impeccable approaches for profiling LMWH complex and heterogeneous mixtures with great variations in sulfation and sequence composition [ 28 ]. In this quest, advances in (i) mass spectrometry (such as LC–MS, CE-MS, CE-LIF (laser-induced fluorescence) and tandem mass spectrometry (also known as MS/MS or MS 2 )) that involve pairing of two or more mass analyzers for increasing their capacity to analyze; (ii) online separations including HPLC (such as size-exclusion chromatography (SEC), strong anion exchange (SAX), reverse-phase ion pairing (RPIP), and hydrophilic interaction chromatography (HILIC)), ion mobility spectrometry (IMS), high-field asymmetric waveform ion mobility spectrometry (FAIMS), and capillary zone electrophoresis (CZE); and (iii) automated analysis software have greatly revolutionized the top-down and bottom-up approaches for precise structural characterization of LMWHs [ 8 ]. Table 3 provides a listing of modern analytical tools for LMWH fine structural and compositional analyses that also need listing in the US and EU pharmacopoeias for assuring quality and purity of the LMWH drugs approved for marketing.…”

“…Several studies have concluded heterogeneity in the GAG chains, their length, molecular weight (MW) distribution, and degree of sulfation as key factors for heparin varying binding tendency with other components in the blood plasma and consequent neutralization [ 1 , 7 ]. Parallel studies regard non-template-driven biosynthesis, the principal cause of complexity, and polydispersity in the GAG chains [ 1 , 8 ]. Consequent upon Andersson et al’s [ 9 ] findings that LMWHs of different MWs influence the coagulation process differently, several heparin fragments with more selective and predictable pharmacological action had been developed [ 2 ] and are the subject of proprietary rights in the USA, Europe, and other countries where substantive patent laws are practiced and enforced.…”

“…As more innovative LMWH products went generic, analytical characterization, control of quality, and regulations including consistency in heparin-derived products supply chains become more and more challenging. Several top-down and bottom-up studies on extensive characterization of LMWH complex structural features for quality control and quality assurance and understanding their diversifying role in medicine and pharmacology [ 11 ], decrypting their non-template driven biosynthesis to fix heterogeneity and polydispersity in their quality attributes [ 8 ], establishing correlation between their structure and biological activity [ 12 ], and discovering new clinical applications [ 13 ] are available in the published literature. However, amongst these, we find very few reports that specifically highlight the patent stats of commercial LMWH drug products for the purposes of defining the boundaries where the generic drug manufacturers have freedom to operate, discuss advances in the analytical techniques that generic/biosimilar drug manufacturers can utilize for the purposes of establishing that the generic/biosimilar LMWHs contain the same active ingredient as the innovator drug product, and conduct residual uncertainty risk assessment studies to demonstrate the absence of any clinically meaningful differences between the generic and the innovator drug products for the purposes of regulatory approval.…”