Detection of Endotoxins: From Inferring the Responses of Biological Hosts to the Direct Chemical Analysis of Lipopolysaccharides

Jackie, Jackie; Lau, Wai Khin; Feng, Hai; Li, Sam Fong Yau

doi:10.1080/10408347.2018.1479958

Cited by 18 publications

(10 citation statements)

References 73 publications

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“…Each batch of produced recombinant opticin was tested using the Limulus amebocyte lysate assay and the Pyros Kinetix Flex tube reader system (Associates of Cape Cod Incorporated; East Falmouth, MA, U.S.A.) to confirm that it was free from bacterial endotoxin prior to its use in the in vivo studies. 11 In Vivo Studies. Animal studies were carried out under the Animals (Scientific Procedures) Act 1986 (project license PPL 70/8120, protocol number 8).…”

Section: Production Of Recombinant Human and Rabbitmentioning

confidence: 99%

Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin

et al. 2020

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Opticin is an endogenous vitreous glycoprotein that may have therapeutic potential as it has been shown that supranormal concentrations suppress preretinal neovascularization. Herein we investigated the pharmacokinetics of opticin following intravitreal injection in rabbits. To measure simultaneously concentrations of human and rabbit opticin, a selected reaction monitoring mass spectrometry assay was developed. The mean concentration of endogenous rabbit opticin in 7 uninjected eyes was measured and found to be 19.2 nM or 0.62 μg/mL. When the vitreous was separated by centrifugation into a supernatant and collagen-containing pellet, 94% of the rabbit opticin was in the supernatant. Intravitreal injection of human opticin (40 μg) into both eyes of rabbits was followed by enucleation at 5, 24, and 72 h and 7, 14, and 28 days postinjection (n = 6 at each time point) and measurement of vitreous human and rabbit opticin concentrations in the supernatant and collagen-containing pellet following centrifugation. The volume of distribution of human opticin was calculated to be 3.31 mL, and the vitreous half-life was 4.2 days. Assuming that rabbit and human opticin are cleared from rabbit vitreous at the same rate, opticin is secreted into the vitreous at a rate of 0.14 μg/day. We conclude that intravitreally injected opticin has a vitreous half-life that is similar to currently available antiangiogenic therapeutics. While opticin was first identified bound to vitreous collagen fibrils, here we demonstrate that >90% of endogenous opticin is not bound to collagen. Endogenous opticin is secreted by the nonpigmented ciliary epithelium into the rabbit vitreous at a remarkably high rate, and the turnover in vitreous is approximately 15% per day.

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Section: Production Of Recombinant Human and Rabbitmentioning

confidence: 99%

Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin

et al. 2020

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“…Among all, biological detection of endotoxins is well established and widely accepted, despite having some limitations. 4 Chemical analysis, however, offers the potential to study endotoxins based on their molecular structures. Cross validation of biological assays and chemical analysis can provide valuable insights into the relationship between the lipopolysaccharide (LPS) structure and its endotoxicity.…”

Section: Introductionmentioning

confidence: 99%

“…Cross validation of biological assays and chemical analysis can provide valuable insights into the relationship between the lipopolysaccharide (LPS) structure and its endotoxicity. 4 …”

Section: Introductionmentioning

confidence: 99%

Rapid and Sensitive Direct Detection of Endotoxins by Pyrolysis–Gas Chromatography–Mass Spectrometry

et al. 2021

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The capability of pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS) for the direct analysis of endotoxins is demonstrated in this research article using the lipopolysaccharides of Pseudomonas aeruginosa 10. Analytical methods based on evolved gas analysis–MS, single-shot (SS) Py–GC–MS, and multishot heart cut Py–GC–MS were investigated. Among the various methods developed, the SS Py–GC–MS method shows superior potential for identifying bacterial endotoxins effectively through their biomarkers. The results obtained were validated with conventional mass spectral analysis after hydrolysis. The method was also evaluated for its robustness based on quality control criteria indicated by the U.S. EPA Method 8270D. When applied onto endotoxins of different Gram-negative bacteria, this method produced vastly distinct pyrograms. The results show that rapid and sensitive direct detection of endotoxins is possible with the Py–GC–MS method developed.

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“…On the one hand, endotoxins are complex components of the outer membrane of Gram-negative bacteria. Structurally, they contain O-antigen, core polysaccharide, and toxic lipid A components [5]. Endotoxins are generally released during bacterial growth (due to rupturing of cell membrane), but they can be released after lysis of bacteria resulting from either autolysis or external lysis.…”

Section: Introductionmentioning

confidence: 99%

Advanced Proteomics as a Powerful Tool for Studying Toxins of Human Bacterial Pathogens

Duport

Alpha-Bazin

Armengaud

2019

Toxins

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Exotoxins contribute to the infectious processes of many bacterial pathogens, mainly by causing host tissue damages. The production of exotoxins varies according to the bacterial species. Recent advances in proteomics revealed that pathogenic bacteria are capable of simultaneously producing more than a dozen exotoxins. Interestingly, these toxins may be subject to post-transcriptional modifications in response to environmental conditions. In this review, we give an outline of different bacterial exotoxins and their mechanism of action. We also report how proteomics contributed to immense progress in the study of toxinogenic potential of pathogenic bacteria over the last two decades.

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Detection of Endotoxins: From Inferring the Responses of Biological Hosts to the Direct Chemical Analysis of Lipopolysaccharides

Cited by 18 publications

References 73 publications

Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin

Intravitreal Pharmacokinetic Study of the Antiangiogenic Glycoprotein Opticin

Rapid and Sensitive Direct Detection of Endotoxins by Pyrolysis–Gas Chromatography–Mass Spectrometry

Advanced Proteomics as a Powerful Tool for Studying Toxins of Human Bacterial Pathogens

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