Parametric Time Warping

Eilers, Paul H.C.

doi:10.1021/ac034800e

Cited by 562 publications

(417 citation statements)

References 7 publications

Supporting

Mentioning

371

Contrasting

Unclassified

Order By: Relevance

“…The resulting oxonium ion profiles were then smoothed by LOESS 42 and adjusted for differences in retention time by parametric time warping. 43,44 The dissimilarities between each pair of samples were calculated as the sum of the absolute differences between resulting oxonium ion relative abundances from 0–80 minutes. For the site-specific calculations, the sample dissimilarities were calculated over time intervals of 0–20 minutes (glycopeptide site 1), 20–36 minutes (glycopeptide site 2/3), 36–55 minutes (glycopeptide site 4), and 55–80 minutes (glycopeptide site 5).…”

Section: Methodsmentioning

confidence: 99%

Data-independent oxonium ion profiling of multi-glycosylated biotherapeutics

Madsen

Farutin

Lin

et al. 2018

mAbs

View full text Add to dashboard Cite

The characterization of glycosylation is required for many protein therapeutics. The emergence of antibody and antibody-like molecules with multiple glycan attachment sites has rendered glycan analysis increasingly more complicated. Reliance on site-specific glycopeptide analysis is therefore necessary to fully analyze multi-glycosylated biotherapeutics. Established glycopeptide methodologies have generally utilized a priori knowledge of the glycosylation states of the investigated protein(s), database searching of results generated from data-dependent liquid chromatography–tandem mass spectrometry workflows, and extracted ion quantitation of the individual identified species. However, the inherent complexity of glycosylation makes predicting all glycoforms on all glycosylation sites extremely challenging, if not impossible. That is, only the “knowns” are assessed. Here, we describe an agnostic methodology to qualitatively and quantitatively assess both “known” and “unknown” site-specific glycosylation for biotherapeutics that contain multiple glycosylation sites. The workflow uses data-independent, all ion fragmentation to generate glycan oxonium ions, which are then extracted across the entirety of the chromatographic timeline to produce a glycan-specific “fingerprint” of the glycoprotein sample. We utilized both HexNAc and sialic acid oxonium ion profiles to quickly assess the presence of Fab glycosylation in a therapeutic monoclonal antibody, as well as for high-throughput comparisons of multi-glycosylated protein drugs derived from different clones to a reference product. An automated method was created to rapidly assess oxonium profiles between samples, and to provide a quantitative assessment of similarity.

show abstract

Section: Methodsmentioning

confidence: 99%

Data-independent oxonium ion profiling of multi-glycosylated biotherapeutics

Madsen

Farutin

Lin

et al. 2018

mAbs

View full text Add to dashboard Cite

show abstract

“…Once acquired, the hyperspectral images were unfolded and the spectra were baseline corrected using the Asymmetric Least Squares (AsLS) (Eilers, 2003) algorithm with a λ value of 10 5 and a p value of 10 -3 . After baseline correction, cosmic rays have been removed with the algorithm developed by Sabin et al (Sabin et al, 2012) with a k value of 15.…”

Section: Data Processingmentioning

confidence: 99%

Thorough characterization of a Self-Emulsifying Drug Delivery System with Raman hyperspectral imaging: A case study

Sacré

Netchacovitch

Bleye

et al. 2015

International Journal of Pharmaceutics

View full text Add to dashboard Cite

Newly developed drugs often have poor bioavailability due to their poor water solubility (BCS class 2 drugs). It is therefore necessary to develop new strategies to enhance their solubility and their activity, among which, Self-Emulsifying Drug Delivery System (SEDDS).The efficacy of the drugs contained in these preparations is mainly affected by the solid state and the particle size of the active pharmaceutical ingredient (API).However, it is quite complex, long and expensive to characterize these parameters with classical techniques such as X-Ray powder diffraction, differential scanning calorimetry or hot stage microscopy.The present article presents, through a case study, the advantages of the Raman hyperspectral imaging in the characterization of such formulations. Indeed, Raman chemical imaging may fully characterize SEDDS with single equipment and operator in a non-destructive way allowing the follow-up of the formulation during stability studies. Raman imaging is therefore a tool of choice in the PAT framework since it increases the knowledge of the formulation and the process. 2A quantitative multivariate method using Raman hyperspectral imaging to assay the API in the lipid based formulation has been developed and fully validated following the "total error" approach.

show abstract

“…In addition to the three more popular algorithms that will be presented below, there are several others that have been developed (Yao et al, 2007;Toppo et al, 2008;Eilers, 2004;Van Nederkassel et al, 2006). In deciding which approach to use, one of the first questions to be answered is if the analysis is to be qualitative or quantitative.…”

Section: Raw Signal Alignmentmentioning

confidence: 99%