Development of an ICP-MS/MS approach for absolute quantification and determination of phosphodiester to phosphorothioate ratio in therapeutic oligonucleotides

LuMA-Functionalized Thermosensitive Hydrogel: A Versatile and Robust Dopamine-Triggered Platform for Diverse Biomolecules Sensing

It is of great significance for the analysis of multiple biomarkers because a single biomarker is difficult to accurately achieve early diagnosis, disease course monitoring, and prognosis evaluation. Herein, a luminescence thermosensitive hydrogel was synthesized by radical polymerization using a methacrylic acid derivative monomer of luminol (LuMA) as luminescent, N-isopropylacrylamide (NIPAM) as thermosensitive monomer, and acrydite-oligonucleotides [dopamine (DA) aptamer, DNA C1, and DNA C2] as recognition elements. The combined DA based on the affinity interaction between the DA and the aptamer on the hydrogel polymer chain was electrochemically oxidized to dopamine quinone during the electrochemiluminescence (ECL) scanning, which effectively quenched the ECL signal of LuMA due to the resonance energy transfer (RET). In addition, the thermosensitive hydrogel showed swelling-collapse characteristics when the temperature was below and above the volume phase transition temperature. Undergoing the collapse process initiated by the temperature, the RET efficiency was further enhanced due to the shortened distance between the energy donor and acceptor, showing a 1.4 times signal amplification and achieving sensitive detection of DA with a limit of detection (LOD) of 1.7 × 10-10 M. For a proof of concept application, coupled with the target-induced release of DA from the DNA-magnetic beads bioconjugations based on duplex-specific nuclease (DSN)-assisted target recycling amplification strategy and DNAzyme cleavage reaction, this ECL-RET approach was successfully used to evaluate multiple targets including miRNA-141 and MUC1 with the LOD of 2.5 aM and 1.6 fg/mL, respectively. The excellent performances of the versatile and robust ECL-RET hydrogel in multiple target sensing showed potential applications in clinical diagnosis and disease therapeutic assay.

Analytical techniques currently used in the pharmaceutical industry for the quality control of RNA-based therapeutics and ongoing developments

The number of RNA-based therapeutics has significantly grown in number on the market over the last 20 years. This number is expected to further increase in the coming years as many RNA therapeutics are being tested in late clinical trials stages. The first part of this paper considers the mechanism of action, the synthesis and the potential impurities resulting from synthesis as well as the strategies used to increase RNA-based therapeutics efficacy. In the second part of this review, the tests that are usually performed in the pharmaceutical industry for the quality testing of antisense oligonucleotides (ASOs), small-interfering RNAs (siRNAs) and messenger RNAs (mRNAs) will be described. In the last part, the remaining challenges and the ongoing developments to meet them are discussed.