31st March 2019

This month:

  • Novel ELISA like assay for small molecules
  • Moxifloxacin aptamer and intellectual property (IP) availability
  • Interesting applications in biologic and biosimilar analysis and cell imaging

With lots of exciting new data ongoing for multiple applications in the commercial and academic space, Aptamer Group would like to share with you information that may be of interest for your research and business goals.

As always, we would love to hear from you to discuss how aptamers can be utilised as the preferred affinity/binding molecules in your research, diagnostics, drug discovery and drug development programs.

Our Novel Solutions – ELISA Like Assays for Small Molecules

Moxifloxacin measured by both fluorescence and qPCR

  • Non competitive assay, measures gain of signal (GoS) for lower background and matrix effects
  • Evaluated in plasma and milk
  • Confirmed by quantitative PCR normalised to an internal standard

    Figure 1. Fluorescently labelled aptamer was immobilised on a suitable ELISA plate and was then incubated with a concentration gradient of Moxifloxacin, prepared in plasma or milk. The fluorescence of the recovered material was measured and plotted against target concentration for each of the different matrices.

    Figure 2: Aptamer quantification by qPCR confirms concentration dependent response to its target in a gain of signal ELISA-like assay format, in complex matrices such as diluted plasma or milk.

    Moxifloxacin Aptamer

    Moxifloxacin is a fluoroquinolone antibiotic used to treat different types of bacterial infections of the skin, sinuses, lungs, or stomach. Fluoroquinolone antibiotics may have serious side effects so should be used sparingly and monitored closely. We have developed and patented the sequence for our Moxifloxacin antibiotic aptamer featured in this Newsletter.

    Moxifloxacin hydrochloride (MW 437.896/mol)

    If you wish to discuss licensing this Intellectual Property for use in your diagnostic applications, please  get in touch with our diagnostic experts.

    In Review and News

    Recent aptamer article reviews:

    Aptamers as quality control tool for production, storage, and biosimilarity of the anti-CD20 biopharmaceutical rituximab

    Wildner, S. et.al. describe the development and characterisation of aptamers to rituximab, a monoclonal anti-CD20 antibody for cancer treatment. Analysis of different rituximab biosimilar candidates revealed a high similarity between the products, with one aptamer able to reveal a structural difference between the originator and a proposed biosimilar product.

    Phosphorothioate-Modified AP613-1 Specifically Targets GPC3 when Used for Hepatocellular Carcinoma Cell Imaging

    Dong, L. et.al. describe aptamer development to Hepatocellular Carcinoma (HC) biomarker GPC3 and use in fluorescent microscopy, flow cytometry, and in vivo imaging of xenograft tumours in nude mice. A truncated version of one specific aptamer demonstrated higher GPC3 binding affinity than the original clone, this was also further improved with chemical modifications.