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Gao J, Xu B, Li P, Zhang F, Zhou P, Su W, Wang J. Universal response method for the quantitative analysis of photodegradation impurities in lomefloxacin hydrochloride ear drops by liquid chromatography coupled with charged aerosol detector. J Pharm Biomed Anal 2023; 234:115552. [PMID: 37393690 DOI: 10.1016/j.jpba.2023.115552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/11/2023] [Accepted: 06/25/2023] [Indexed: 07/04/2023]
Abstract
In terms of risk assessment especially for the impurities with different ultraviolet responses, quantitative analysis without the availability of corresponding reference substances currently poses a challenge. In this study, a universal response method was established for the quantitative analysis of photodegradable impurities in lomefloxacin hydrochloride ear drops by high performance liquid chromatography-charged aerosol detector (HPLC-CAD) for the first time. The chromatographic conditions and CAD parameters were optimized for a good separation and sensitivity. The uniform response of developed method was validated by impurity reference substances with different ultraviolet responses. In the gradient compensation HPLC-CAD method validation, good linearities were obtained with coefficient of determination (R2) all greater than 0.999 for lomefloxacin and impurity reference substances. The average recoveries of the impurities were 98.63%- 102.18% by UV and 97.92%- 102.57% by CAD, respectively. RSDs all were less than 2.5% for intra-day and inter-day precision by UV and CAD, with good precision and accuracy. The correction factor experimental results showed that the developed method provided a uniform response to the impurities with differences chromophores in lomefloxacin. The effects of packaging materials and excipients on the photodegradation were also investigated using the developed method. The results of correlation analysis showed that the packaging materials with low light transmittance and the organic excipients (glycerol and ethanol) could significantly improve the stability of lomefloxacin hydrochloride ear drops. The developed HPLC-CAD quantification method was a reliable and universal response method for quantitative analysis of impurities in the lomefloxacin. This study also revealed the key factors affecting the photodegradation of lomefloxacin hydrochloride ear drops, which guided enterprises to improve drug prescription and packaging materials and ensure the public medication safety.
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Affiliation(s)
- Jiarui Gao
- Zhejiang University of Technology, Hangzhou 310014, China
| | - Bingyong Xu
- Zhejiang University of Technology, Hangzhou 310014, China
| | - Ping Li
- Zhejiang University of Technology, Hangzhou 310014, China
| | - Fengmei Zhang
- Zhejiang Institute for Food and Drug Control, Key Laboratory for Core Technology of Generic Drug Evaluation National Medical Product Administration & Key Laboratory of Drug Contacting Materials Quality Control of Zhejiang Province, Hangzhou 310052, China
| | - Ping Zhou
- Zhejiang University of Technology, Hangzhou 310014, China
| | - Weike Su
- Zhejiang University of Technology, Hangzhou 310014, China.
| | - Jian Wang
- Zhejiang University of Technology, Hangzhou 310014, China; Zhejiang Institute for Food and Drug Control, Key Laboratory for Core Technology of Generic Drug Evaluation National Medical Product Administration & Key Laboratory of Drug Contacting Materials Quality Control of Zhejiang Province, Hangzhou 310052, China.
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2
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Shahraz A, Lin Y, Mbroh J, Winkler J, Liao H, Lackmann M, Bungartz A, Zipfel PF, Skerka C, Neumann H. Low molecular weight polysialic acid binds to properdin and reduces the activity of the alternative complement pathway. Sci Rep 2022; 12:5818. [PMID: 35388026 PMCID: PMC8987038 DOI: 10.1038/s41598-022-09407-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 03/21/2022] [Indexed: 11/09/2022] Open
Abstract
Sialic acids as the terminal caps of the cellular glycocalyx play an essential role in self-recognition and were shown to modulate complement processes via interaction between α2,3-linked sialic acids and complement factor H. Previously, it was suggested that low molecular weight α2,8-linked polysialic acid (polySia avDP20) interferes with complement activation, but the exact molecular mechanism is still unclear. Here, we show that soluble polySia avDP20 (molecular weight of ~ 6 kDa) reduced the binding of serum-derived alternative pathway complement activator properdin to the cell surface of lesioned Hepa-1c1c7 and PC-12 neuroblastoma cells. Furthermore, polySia avDP20 added to human serum blocked the alternative complement pathway triggered by plate-bound lipopolysaccharides. Interestingly, no inhibitory effect was observed with monosialic acid or oligosialic acid with a chain length of DP3 and DP5. In addition, polySia avDP20 directly bound properdin, but not complement factor H. These data show that soluble polySia avDP20 binds properdin and reduces the alternative complement pathway activity. Results strengthen the previously described concept of self-recognition of sialylation as check-point control of complement activation in innate immunity.
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Affiliation(s)
- Anahita Shahraz
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Yuchen Lin
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Joshua Mbroh
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Jonas Winkler
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Huan Liao
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Marie Lackmann
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Annemarie Bungartz
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.,Infection Biology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Harald Neumann
- Neural Regeneration Unit, Institute of Reconstructive Neurobiology, Medical Faculty and University Hospital of Bonn, University of Bonn, Venusberg-Campus 1, 53127, Bonn, Germany.
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Villanueva-Cabello TM, Gutiérrez-Valenzuela LD, Salinas-Marín R, López-Guerrero DV, Martínez-Duncker I. Polysialic Acid in the Immune System. Front Immunol 2022; 12:823637. [PMID: 35222358 PMCID: PMC8873093 DOI: 10.3389/fimmu.2021.823637] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 12/28/2021] [Indexed: 01/01/2023] Open
Abstract
Polysialic acid (polySia) is a highly regulated polymer of sialic acid (Sia) with such potent biophysical characteristics that when expressed drastically influences the interaction properties of cells. Although much of what is known of polySia in mammals has been elucidated from the study of its role in the central nervous system (CNS), polySia is also expressed in other tissues, including the immune system where it presents dynamic changes during differentiation, maturation, and activation of different types of immune cells of the innate and adaptive response, being involved in key regulatory mechanisms. At least six polySia protein carriers (CCR7, ESL-1, NCAM, NRP2, ST8Sia 2, and ST8Sia 4) are expressed in different types of immune cells, but there is still much to be explored in regard not only to the regulatory mechanisms that determine their expression and the structure of polySia chains but also to the identification of the cis- and trans- ligands of polySia that establish signaling networks. This review summarizes the current knowledge on polySia in the immune system, addressing its biosynthesis, its tools for identification and structural characterization, and its functional roles and therapeutic implications.
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Affiliation(s)
- Tania M. Villanueva-Cabello
- Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - Lya D. Gutiérrez-Valenzuela
- Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Roberta Salinas-Marín
- Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | | | - Iván Martínez-Duncker
- Laboratorio de Glicobiología Humana y Diagnóstico Molecular, Centro de Investigación en Dinámica Celular, Instituto de Investigación en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
- *Correspondence: Iván Martínez-Duncker,
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Zhao X, He Y, Chen J, Zhang J, Chen L, Wang B, Wu C, Yuan Y. Identification and direct determination of fatty acids profile in oleic acid by HPLC-CAD and MS-IT-TOF. J Pharm Biomed Anal 2021; 204:114238. [PMID: 34273659 DOI: 10.1016/j.jpba.2021.114238] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Revised: 05/17/2021] [Accepted: 06/29/2021] [Indexed: 01/27/2023]
Abstract
Oleic acid is a pharmaceutical excipient and has been widely used in many dosage forms. It remains unclear in terms of the fatty acids (FAs) profile. In this study, a sensitive and direct method based on high-performance liquid chromatography coupled with charged aerosol detector (HPLC-CAD) was developed to study the compositions of oleic acid. The chromatographic conditions were optimized to achieve good separation and high sensitivity. The components of oleic acid were identified by ion trap/time of flight mass spectrometry (MS-IT-TOF). Twenty-seven FAs were identified based on the exact mass-to-charge ratio and fragments, among which 13 FAs were confirmed with the reference standards. Nine FAs in the oleic acid samples including oleic acid, linolenic acid, myristic acid, palmitoleic acid, linoleic acid, palmitic acid, stearic acid, arachidic acid and behenic acid were simultaneously determined by the developed HPLC-CAD, which showed good linearity with r2>0.999. The limit of detection (LOD) and limit of quantification (LOQ) of 9 FAs were 0.006-0.1 μg mL-1 and 0.032-0.22 μg mL-1, respectively. The components with concentration level not less than 0.03 % (referring to the sample concentration of 1.0 mg mL-1) can be quantified. The mean recovery values of 9 FAs ranged from 96.5%-103.6% at three concentration levels of 80 %, 100 % and 120 %. The repeatability and intermediate precision were less than 5.0 % for oleic acid and components with concentration levels more than 0.05 %. In contrast to the conventional pre-column derivatization gas chromatography (GC), HPLC-CAD could unbiasedly and directly detect more components, especially the FAs with long carbon chains. Overall, the developed novel HPLC-CAD method can ameliorate the deficiency of the indirect GC method recorded in current pharmacopeias, thus having great potential for the comprehensive understanding and quality control of oleic acid.
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Affiliation(s)
- Xun Zhao
- Chemical Laboratory Second Laboratory, Jiangsu Institute for Drug and Food Control, Nanjing, China; NMPA Key Laboratory for Impurity Profile of Chemical Drugs, National Medical Products Administration, Beijing, China
| | - Yuanzi He
- China Pharmaceutical University, Nanjing, China
| | - Jungen Chen
- China Pharmaceutical University, Nanjing, China
| | | | - Lei Chen
- Chinese Pharmacopoeia Commission, Beijing, China
| | - Baocheng Wang
- Nanjing Well Pharmaceutical Co., LTD., Nanjing, China
| | - Chunyong Wu
- China Pharmaceutical University, Nanjing, China.
| | - Yaozuo Yuan
- Chemical Laboratory Second Laboratory, Jiangsu Institute for Drug and Food Control, Nanjing, China; NMPA Key Laboratory for Impurity Profile of Chemical Drugs, National Medical Products Administration, Beijing, China.
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Langer C, Süss R. HPLC-DAD-CAD-based approach for the simultaneous analysis of hydrophobic drugs and lipid compounds in liposomes and for cyclodextrin/drug inclusion complexes. J Pharm Biomed Anal 2021; 201:114120. [PMID: 33991808 DOI: 10.1016/j.jpba.2021.114120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/29/2021] [Accepted: 05/01/2021] [Indexed: 01/06/2023]
Abstract
In recent decades liposomes have become attractive carriers for hydrophobic drugs to enhance their solubility and improve their therapeutic application. For liposomal drug products, both drug and lipid quantification are required by regulatory authorities, making the implementation of precise quantification methods a step of crucial importance in formulation development and quality control. Therefore, the present study is focused on the development and validation of a simple and time-saving method for the simultaneous analysis of hydrophobic drugs and conventional liposomal components. The new HPLC method was established with a combined detection by a diode array detector (DAD) and a corona charged aerosol detector (CAD). As a wide calibration range of the liposomal components can be achieved (10-1000 μg/mL), the analysis of samples with different drug to lipid ratios is enabled. Moreover, an excellent precision including repeatability and low limits of detection (≤ 1.8 μg/mL) and limits of quantification (≤ 5.9 μg/mL) were accomplished for all analytes. The method was successfully applied to liposomes incorporating mitotane. Everolimus was additionally analyzed as hydrophobic model drug. Furthermore, cyclodextrin/mitotane inclusion complexes were investigated to proof a broad range of applications for the developed method.
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Affiliation(s)
- Carolin Langer
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg, Sonnenstrasse 5, 79104, Freiburg, Germany.
| | - Regine Süss
- Institute of Pharmaceutical Sciences, Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg, Sonnenstrasse 5, 79104, Freiburg, Germany
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Bartling B, Brüchle NC, Rehfeld JS, Boßmann D, Fiebig T, Litschko C, Fohrer J, Gerardy-Schahn R, Scheper T, Beutel S. Accelerated production of α2,8- and α2,9-linked polysialic acid in recombinant Escherichia coli using high cell density cultivation. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 28:e00562. [PMID: 33304838 PMCID: PMC7711218 DOI: 10.1016/j.btre.2020.e00562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/05/2020] [Accepted: 11/17/2020] [Indexed: 11/29/2022]
Abstract
Polysialic acid (polySia) are α2,8- and/or α2,9-linked homopolymers with interesting properties for meningococcal vaccine development or the cure of human neurodegenerative disorders. With the goal to avoid large scale production of pathogenic bacteria, we compare in the current study the efficacy of conventional polySia production to recombinant approaches using the engineered laboratory safety strain E. coli BL21. High cell density cultivation (HCDC) experiments were performed in two different bioreactor systems. Increased cell densities of up to 11.3 (±0.4) g/L and polySia concentrations of up to 774 (±18) mg/L were reached in E. coli K1. However, cultivation of engineered E. coli BL21 strains delivered comparable cell densities but a maximum of only 133 mg/L polySia. Using established downstream procedures, host cell DNA and proteins were removed. All recombinant polySia products showed an identical degree of polymerization >90. Polymers with different glycosidic linkages could be successfully differentiated by nuclear magnetic resonance spectroscopy.
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Affiliation(s)
- Bastian Bartling
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Nora C. Brüchle
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Johanna S. Rehfeld
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Daniel Boßmann
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Christa Litschko
- Institute of Clinical Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Jörg Fohrer
- Institute of Organic Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Rita Gerardy-Schahn
- Institute of Clinical Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Thomas Scheper
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Sascha Beutel
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
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7
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Recent applications of the Charged Aerosol Detector for liquid chromatography in drug quality control. J Chromatogr A 2020; 1619:460911. [DOI: 10.1016/j.chroma.2020.460911] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 01/12/2023]
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8
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Universal quantification method of degradation impurities in 16-membered macrolides using HPLC-CAD and study on source of the impurities. J Pharm Biomed Anal 2020; 184:113170. [DOI: 10.1016/j.jpba.2020.113170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 01/09/2023]
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Bartling B, Rehfeld JS, Boßmann D, de Vries I, Fohrer J, Lammers F, Scheper T, Beutel S. Determination of the Structural Integrity and Stability of Polysialic Acid during Alkaline and Thermal Treatment. Molecules 2019; 25:E165. [PMID: 31906121 PMCID: PMC6982714 DOI: 10.3390/molecules25010165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 12/19/2019] [Accepted: 12/21/2019] [Indexed: 11/16/2022] Open
Abstract
Polysialic acid (polySia) is a linear homopolymer of varying chain lengths that exists mostly on the outer cell membrane surface of certain bacteria, such as Escherichia coli (E. coli) K1. PolySia, with an average degree of polymerization of 20 (polySia avDP20), possesses material properties that can be used for therapeutic applications to treat inflammatory neurodegenerative diseases. The fermentation of E. coli K1 enables the large-scale production of endogenous long-chain polySia (DP ≈ 130) (LC polySia), from which polySia avDP20 can be manufactured using thermal hydrolysis. To ensure adequate biopharmaceutical quality of the product, the removal of byproducts and contaminants, such as endotoxins, is essential. Recent studies have revealed that the long-term incubation in alkaline sodium hydroxide (NaOH) solutions reduces the endotoxin content down to 3 EU (endotoxin units) per mg, which is in the range of pharmaceutical applications. In this study, we analyzed interferences in the intramolecular structure of polySia caused by harsh NaOH treatment or thermal hydrolysis. Nuclear magnetic resonance (NMR) spectroscopy revealed that neither the incubation in an alkaline solution nor the thermal hydrolysis induced any chemical modification. In addition, HPLC analysis with a preceding 1,2-diamino-4,5-methylenedioxybenzene (DMB) derivatization demonstrated that the alkaline treatment did not induce any hydrolytic effects to reduce the maximum polymer length and that the controlled thermal hydrolysis reduced the maximum chain length effectively, while cost-effective incubation in alkaline solutions had no adverse effects on LC polySia. Therefore, both methods guarantee the production of high-purity, low-molecular-weight polySia without alterations in the structure, which is a prerequisite for the submission of a marketing authorization application as a medicinal product. However, a specific synthesis of low-molecular-weight polySia with defined chain lengths is only possible to a limited extent.
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Affiliation(s)
- Bastian Bartling
- Institute of Technical Chemistry, Leibniz University Hannover, 30167 Hannover, Germany; (B.B.); (J.S.R.); (D.B.); (I.d.V.); (T.S.)
| | - Johanna S. Rehfeld
- Institute of Technical Chemistry, Leibniz University Hannover, 30167 Hannover, Germany; (B.B.); (J.S.R.); (D.B.); (I.d.V.); (T.S.)
| | - Daniel Boßmann
- Institute of Technical Chemistry, Leibniz University Hannover, 30167 Hannover, Germany; (B.B.); (J.S.R.); (D.B.); (I.d.V.); (T.S.)
| | - Ingo de Vries
- Institute of Technical Chemistry, Leibniz University Hannover, 30167 Hannover, Germany; (B.B.); (J.S.R.); (D.B.); (I.d.V.); (T.S.)
| | - Jörg Fohrer
- Institute of Organic Chemistry, Leibniz University Hannover, 30167 Hannover, Germany;
| | - Frank Lammers
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, 65929 Frankfurt am Main, Germany;
| | - Thomas Scheper
- Institute of Technical Chemistry, Leibniz University Hannover, 30167 Hannover, Germany; (B.B.); (J.S.R.); (D.B.); (I.d.V.); (T.S.)
| | - Sascha Beutel
- Institute of Technical Chemistry, Leibniz University Hannover, 30167 Hannover, Germany; (B.B.); (J.S.R.); (D.B.); (I.d.V.); (T.S.)
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Guo X, Elkashef SM, Loadman PM, Patterson LH, Falconer RA. Recent advances in the analysis of polysialic acid from complex biological systems. Carbohydr Polym 2019; 224:115145. [PMID: 31472857 DOI: 10.1016/j.carbpol.2019.115145] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 12/25/2022]
Abstract
Polysialic acid (polySia) is a unique, well-characterised carbohydrate polymer highly-expressed on the cell surface of neurons in the early stages of mammalian brain development. Post-embryogenesis, it is also re-expressed in a number of tumours of neuroendocrine origin. It plays important roles in modulating cell-cell, and cell-matrix adhesion and migration, tumour invasion and metastasis. Techniques for structural and quantitative characterisation of polySia from tumours and cancer cells are thus essential in exploring the relationship between polySia expression levels and structural and functional changes associated with cancer progression and metastasis. A variety of techniques have been developed to structurally and quantitatively analyse polySia in clinical tissues and other biological samples. In this review, analytical approaches used for the determination of polySia in biological matrices in the past 20 years are discussed, with a particular focus on chemical approaches, and quantitative analysis.
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Affiliation(s)
- Xiaoxiao Guo
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, United Kingdom
| | - Sara M Elkashef
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, United Kingdom
| | - Paul M Loadman
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, United Kingdom
| | - Laurence H Patterson
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, United Kingdom
| | - Robert A Falconer
- Institute of Cancer Therapeutics, Faculty of Life Sciences, University of Bradford, Bradford BD7 1DP, United Kingdom.
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