Biography:

One of their most recent publications is Comparison of a Luminescent Oxygen Channeling Immunoassay and an ELISA for detecting Insulin Aspart in human serum. Which was published in journal Journal of Pharmaceutical and Biomedical Analysis.

More information about Signe Beck Petersen research including statistics on their citations can be found on their Copernicus Academic profile page.

Signe Beck Petersen's Articles: (3)

Comparison of a Luminescent Oxygen Channeling Immunoassay and an ELISA for detecting Insulin Aspart in human serum

AbstractThe study was a comparison between a Luminescent Oxygen Channeling Immunoassay (LOCI™) and an enzyme-linked immunosorbent assay (ELISA) for quantification of Insulin Aspart (IAsp) in human serum. The advantage of LOCI™ compared to ELISA is reduced workload and higher throughput.The ELISA assay was performed as published (Andersen et al., 2000 [5]). The LOCI™ followed a 2-step reaction. First, the sample was incubated for 1 h with a mixture of biotinylated antibody specific for IAsp and beads coated with insulin-detecting antibody. This step was followed by a 30-min incubation with beads covalently coated with streptavidin. When the beads were brought in proximity through binding of IAsp, light was generated from a chemiluminescent reaction in the beads. This light was measured and quantified.Spiked samples with different concentrations of IAsp were prepared in human serum to compare ELISA and LOCI™. Human serum samples (n = 510) from a pilot study with healthy subjects receiving IAsp were also analysed and compared in the two assays.Higher precision, improved accuracy and a wider analytical range were found using LOCI™ compared to ELISA. However, sample haemolysis interfered more when using LOCI™ than ELISA. The IAsp concentrations determined in the human serum samples from the pilot study gave a good correlation between the two assays.In conclusion, LOCI™ can determine IAsp in human serum just as well as ELISA. Using LOCI™ reduces the workload, which is particularly useful when handling large sample sizes.

Evaluation of alkylmaltosides as intestinal permeation enhancers: Comparison between rat intestinal mucosal sheets and Caco-2 monolayers

AbstractAlkylmaltosides are a class of non-ionic surfactant currently in clinical trials to improve nasal permeation of peptide drugs, however few studies have detailed their potential effects on intestinal permeation enhancement. Tetradecyl maltoside (TDM, C14), was examined in Caco-2 monolayers and in isolated rat jejunal and colonic mucosae mounted in Ussing chambers. Dodecyl maltoside (DDM, C12) was examined in mucosae. Parameters measured included critical micelle concentration (CMC), transepithelial electrical resistance (TEER), and apparent permeability coefficients (Papp) of paracellular and transcellular flux markers. TDM and DDM decreased TEER and increased the Papp of [14C]-mannitol and FD-4 across Caco-2 monolayers and colonic mucosae in the concentration range of 0.01–0.1% w/v, concentrations much higher than the CMC. Remarkably, neither agent had any effect on the TEER or fluxes of jejunal mucosae. Histopathology, cell death assays (MTT and LDH) and sub-lethal high content cytotoxicity analyses (HCA) were carried out with TDM. Exposure of colonic mucosae to high concentrations of TDM had no major effects on gross histology and ion transport function was retained. In Caco-2, HCA data at sub-lethal concentrations of TDM was consistent with the action of a mild non-ionic surfactant. In conclusion, alkylmaltosides are effective non-toxic permeation enhancers in isolated colonic tissue and their inclusion in oral peptide formulations directed to that intestinal region warrants further study.

Colonic absorption of salmon calcitonin using tetradecyl maltoside (TDM) as a permeation enhancer

AbstractCalcitonin is used as a second line treatment of postmenopausal osteoporosis, but widespread acceptance is somewhat limited by subcutaneous and intranasal routes of delivery. This study attempted to enable intestinal sCT absorption in rats using the mild surfactant, tetradecyl maltoside (TDM) as an intestinal permeation enhancer. Human Caco-2 and HT29-MTX-E12 mucus-covered intestinal epithelial monolayers were used for permeation studies. Rat in situ intestinal instillation studies were conducted to evaluate the absorption of sCT with and without 0.1 w/v% TDM in jejunum, ileum and colon. TDM significantly enhanced sCT permeation across intestinal epithelial monolayers, most likely due to combined paracellular and transcellular actions. In situ, TDM caused an increased absolute bioavailability of sCT in rat colon from 1.0% to 4.6%, whereas no enhancement increase was observed in ileal and jejunal instillations. Histological analysis suggested mild perturbation of colonic epithelia in segments instilled with sCT and TDM. These data suggest that the membrane composition of the colon is different to the small intestine and that it is more amenable to permeation enhancement. Thus, formulations designed to release payload in the colon could be advantageous for systemic delivery of poorly permeable molecules.

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