Electrochemical analysis of total phospholipids in human serum for severe sepsis diagnosis

One-step ultra-rapid immunoassay of calcitonin gene-related peptide for migraine diagnosis

Migraine is known to be caused by calcitonin gene-related peptide (CGRP), prompting the need for quantitative analysis of CGRP for the clinical treatment of monoclonal antibodies targeting CGRP. Since CGRP is cleaved by proteolytic enzymes post-blood collection, rapid analysis methods are required. In this study, a one-step immunoassay for CGRP was developed using chemically mimicking peptides (mimotopes) with an analysis time of 32 min. Four clones from an Fv-antibody library were screened using two types of monoclonal antibodies against CGRP. Mimotopes for each monoclonal antibody were synthesized into peptides of 15 residues. The binding affinity (KD) was estimated, and the interaction with monoclonal antibodies was analyzed using docking simulations. Finally, a one-step immunoassay for CGRP was demonstrated using migraine patient samples (n = 57) and healthy volunteer controls (n = 18). The limit of detection (LOD) of one-step immunoassay based on Fremanezumab (mimotope F1) was estimated to be 8.8 pg/mL with the limit of quantification (LOQ) of 125.9 pg/mL. And, the one-step immunoassay based on Galcanezumab (mimotope G7) showed the LOD of 9.4 pg/mL and the LOQ of 84.7 pg/mL. The total analysis time was estimated to be approximately 32 min and the assay results were estimated to be statistically consistent with conventional CGRP assay.

Sepsis Diagnosis Based on a Parylene Matrix Chip Using LPC16:0 as a Biomarker in Comparison with Colorimetry of Total Phospholipid

For the medical diagnosis of sepsis, it is crucial to differentiate infectious inflammation from noninfectious symptoms to prevent acute aggravation. Herein, a diagnosis for early stage sepsis was performed using LPC 16:0 and total phospholipids as small molecular biomarkers. The measurement of LPC 16:0 was conducted using a parylene matrix chip, which was developed to effectively detect small molecules in laser desorption/ionization mass spectrometry (LDI-MS). Meanwhile, the total phospholipid level was measured using colorimetry, following an enzymatic assay. Next, the two biomarkers were analyzed in serum samples from healthy volunteers, systemic inflammatory response syndrome (SIRS) patients, and sepsis patients. Diagnostic criteria were established based on the biomarker intensities observed in each patient group. After the measurements were conducted, the interference in phospholipid analysis due to hemoglobin contamination was considered. Additionally, the analytical parameters from biomarker detection were statistically interpreted and compared with those of conventional diagnostic standards. Finally, the diagnostic performance of each biomarker was evaluated by analyzing the biomarker levels between patient groups and examining their overlapping extents in box plots to distinguish sepsis from noninfectious inflammatory symptoms.

A one-step immunoassay based on switching peptides for diagnosis of porcine epidemic diarrhea virus (PEDV) using screened Fv-antibodies

In this study, a one-step immunoassay for porcine epidemic diarrhea virus (PEDV) based on Fv-antibodies and switching peptides was developed, and the assay results of PEDV were obtained by just mixing samples without any further reaction or washing steps. The Fv-antibodies with binding affinity to the spike protein of PEDV were screened from the Fv-antibody library using the receptor-binding domain (RBD) of the spike protein as a screening probe. Screened Fv-antibodies with binding affinities to the RBD antigen were expressed, and the binding constants (KD) were calculated to be 83-142 nM. The one-step immunoassay for the detection of PEDV was configured as a displacement immunoassay using a fluorescence-labeled switching peptide. The one-step immunoassay based on switching peptides was performed using PEDV, and the limit of detection (LOD) values for PEDV detection were estimated to be Ct = 39.7-36.4. Compared with the LOD value for a conventional lateral flow immunoassay (Ct = 33.0), the one-step immunoassay showed a remarkably improved LOD for the detection of PEDV. Finally, the interaction between the screened Fv-antibodies and the PEDV RBD was investigated using docking simulations and compared with the amino acid sequences of the receptors on host cells, such as aminopeptidase N (APN) and angiotensin-converting enzyme-2 (ACE-2).