An integrated methodology for quality assessment of therapeutic antibodies with potential long circulation half-life in harvested cell culture fluid using FcRn immobilized hydrophilic magnetic graphene.

Designing modified therapeutic antibodies with enhanced FcRn-binding affinity holds promise in the extension of circulation half-lives and potential refinement of pharmacokinetics. During the development of these new-generation therapeutic antibodies, FcRn binding affinity of IgGs is emphasized and monitored as a critical quality attribute (CQA), alongside other critical assessments including titer and aggregation level. However, the traditional workflow for assessing the overall quality of expressed IgGs in harvested cell culture fluid (HCCF) is blamed to be cumbersome and time-consuming. This study presents an integrated methodology for the rapid quality assessment of IgGs in HCCF by selectively extracting IgGs with favorable high FcRn affinity for subsequent analysis using size exclusion chromatography (SEC). The approach utilizes innovative adsorbents known as FcRn immobilized hydrophilic magnetic graphene (MG@PDA@PAMAM-FcRn) in a magnetic solid-phase extraction (MSPE) process. To simulate the in vivo binding dynamics, MSPE binding and dissociation was performed at pH 6.0 and 7.4, respectively. The composite have demonstrated enhanced extraction efficiency and impurity removal ability in comparison to commercially available magnetic beads. The SEC monomer peak area value provides the output of this method, the ranking of which enabled the facile identification of superior HCCF samples with high overall quality of IgG. Optimization of MSPE parameters was performed, and the method was validated for specificity, precision, sensitivity, and accuracy. The proposed method exhibited an analytical time of 0.6 h, which is 7-22 times shortened in comparison to the conventional workflow.

Magnetic solid-phase extraction based on polydopamine-coated magnetic nanoparticles for rapid and sensitive analysis of eleven illicit drugs and metabolites in wastewater with the aid of UHPLC-MS/MS.

The quantification of illicit drugs in wastewater has become a valuable tool for monitoring illicit drug abuse. The commonly utilized methods for detecting drugs in wastewater require a substantial sample volume, extended pretreatment durations, and intricate procedures. This study first employed polydopamine-coated magnetic nanocomposites as adsorbents for magnetic solid-phase extraction, combined with UPLC-MS/MS, to simultaneously determine the concentrations of eleven common illicit drugs in wastewater. The synthesis process for Fe3O4@PDA is straightforward and high-yield. Benefiting from the strong magnetic response, good dispersibility, and abundant binding sites of the prepared nanocomposites, the extraction of illicit drugs from wastewater could be achieved in just 15 min. The method exhibited satisfactory limits of quantitation (ranging from 5 to 10 ng/L), commendable accuracy (ranging from 90.59 % to 106.80 %), good precision (with RSDs below 10 %), and less sample consumption (only 1 mL). The efficacy of this method was successfully validated through its application to actual wastewater samples collected from ten wastewater treatment plants. The results indicated that morphine, codeine, methamphetamine, and ketamine were the predominant illicit drugs present in the samples. The method developed is able to meet the needs of common illicit drug monitoring and high-throughput analysis requirements.

Tetrodotoxin and Its Analogues in Food: Recent Updates on Sample Preparation and Analytical Methods Since 2012.

Tetrodotoxin (TTX), found in various organisms including pufferfish, is an extremely potent marine toxin responsible for numerous food poisoning accidents. Due to its serious toxicity and public health threat, detecting TTX and its analogues in diverse food matrices with a simple, fast, efficient method has become a worldwide concern. This review summarizes the advances in sample preparation and analytical methods for the determination of TTX and its analogues, focusing on the latest development over the past five years. Current state-of-the-art technologies, such as solid-phase microextraction, online technology, novel injection technology, two-dimensional liquid chromatography, high-resolution mass spectrometry, newly developed lateral flow immunochromatographic strips, immunosensors, dual-mode aptasensors, and nanomaterials-based approaches, are thoroughly discussed. The advantages and limitations of different techniques, critical comments, and future perspectives are also proposed. This review is expected to provide rewarding insights to the future development and broad application of pretreatment and detection methods for TTX and its analogues.

Core-shell structured magnetic covalent-organic frameworks for rapid extraction and preconcentration of okadaic acid in seawater and shellfish followed with LC-MS/MS quantification.

Core-shell structured magnetic covalent-organic frameworks (Fe3O4@TaTp) were facilely synthesized based on one-step functionalization at room temperature and applied for magnetic solid-phase extraction of okadaic acid from seawater and shellfish prior to LC-MS/MS detection. Parameters, including adsorbent amount, extraction time, desorption solution, and desorption time which could affect the extraction efficiency, were respectively investigated. The developed methods demonstrated good linearity (R2 > 0.99), acceptable accuracy and good precision (<15%), and low limit of detection (0.5 pg·mL-1 for seawater and 0.04 µg·kg-1 for shellfish). The amount of the material used (1 mg for seawater and 5 mg for shellfish) and the time required (4 min for seawater and 15 min for shellfish) for extracting analyte from 5 mL of seawater and 2 g of shellfish are both greatly shortened compared with the previous reports. In addition, we successfully applied this method to real sample analysis.

Magnetic solid phase extraction followed with LC-MS/MS for determination of glimepiride in beagle dog plasma and its application to bioequivalence study.

In this study, the core-shell polydopamine-coated magnetic nanomaterials were synthesized with one-step approach and applied as magnetic solid phase extraction adsorbents combined with LCMS/MS for quantification of the diabetes drug glimepiride in beagle dog plasma. The Fe3O4@PDA nanomaterials have strong magnetic response, good dispersibility in aqueous solution, and numerous binding sites for π-π interaction and hydrogen bonding with glimepiride. Based on these merits, glimepiride could be quickly extracted and separated from plasma within 10min. The established method has good linearity (1-2000ng•mL-1), low quantification limit (1ng•mL-1), good precision (RSDs≤12 %), and satisfactory extraction recovery (71.20-85.70 %). Moreover, we successfully applied this method to the bioequivalence study of generic and innovator products of glimepiride in beagle dog plasma.