Phage Cryopreservation Published.
With our partners at Cytivia (who host Prof Gibson as a Royal Society Industry fellow) and the Sagona Group (School of life sciences) we have investigated how polymers can be used to cryopreserve bacteriophages. Methods to freeze cells have attracted huge interest of late, for application in cell based therapies and biotechnology.We have, for example, developed macromolecular cryoprotectants which can control ice growth/formation and/or protect cells during freezing. However, virus storage is less explored. Viruses are essential from as vaccines, to vectors to engineer cells. Bacteriophages (phage) are specific bacterial viruses and several are used already to remove bacterial infections and they may have application in the future as therapies, or diagnostics. In this work, we observed (surprisingly) that just adding a small amount of PEG (poly(ethyleneglycol) protected phage during several freeze/thaw cycles at both -80 and -20 C. The mechanism of this was not clear, but ice growth (and its inhibition) was ruled out. We are continuing to study this, and to evaluate the use of polymers in many cryopreservation scenarios.
Read the paper here
Lateral Flow Glyco-Assay Demonstration of Concept Published
With our partners Iceni Diagnostics, we have been exploring lateral flow diagnostics (LFDs), and in particular replacing the need for antibodies with glycans and polymers. We have previously demonstrated that glycans can be used for detection, and in a flow-through device but we had not constructed a complete device with glycans on the stationary phase (the paper) AND mobile phase (gold nanoparticles). Our latest work, published in Advanced Healthcare Materials, shows a proof of concept that a 'lateral flow glyco assay', where only glycans are used for detection is possible. We fine-tune the polymer linkers and nanoparticle size, showing how these can modulate the signal outputs, without needing to tune the 'binder' (the glycan) - this is a significant benefit, when trying to ensure devices are selective. We show this using two lectins (carbohydrate binding proteins) and assemble complete devices for lectin detection. We think this has huge potential spanning pandemic preparedness to tools for fundamental glycoscience.
Read the paper here
Polymeric-Test Line for Lateral Flow Devices Published
Our latest work into how we can re-engineer lateral flow tests with polymeric components is published! Lateral flow tests (LFDs) are widely used for home pregnancy tests, to monitor the spread of COVID-19. A typical LFD uses antibodies on a gold nanoparticle (which makes the red colour) and forms a 'sandwich' with the analyte and another anti-body immobilised onto the paper-surface of the device. We have recently shown how synthetic polymers can be used on the gold nanoparticle surface to anchor targetting ligands which are not antibodies (e.g. glycans). In this work we explored using polymers to immobilise onto the test line (i.e. onto the paper). The current methods to immobilise non-antibody ligands is to chemically conjugate ligands onto polymeric carriers, which is non-trivial. We show here that poly(vinyl pyrrolidone) can be immobilised onto the paper, due to its ability to be dissolved in water (essential for printing) but being sufficiently hydrophobic to be retained. We install biotin and N-acetyl galactosamine as model capture units, showing that the PVP test line can be used. This is the first step towards making a robust and versatile polymeric capture agent to expand the scope of LFDs beyond antibodies.
Read the paper here:
University PhD Scholarships are open
The University of Warwick has scholarships open for PhD candidates. These include EU/overseas students in many cases.
Check them out at the link below, and get in touch if you are interested in improving human health with biomaterials; glycobiology, diagnostics, cell/protein storage, ice binding-proteins, cryobiology or polymer chemistry!
PhD Vacancies in Group
We have vacancies now open for PhDs in the team. Using biomaterials, to probe important health-related challenges. All vacancies listed here.
COVID-19 detection in a rapid glycan-based diagnostic device
Our latest work, investigating SARS-COV-2 glycan interactions, and translation to diagnostic technology has been published in ACS sensors. Last year we discovered that the SARS-COV-2 spike protein could bind sialic acids (glycans found on cell surfaces and in the respiratory tract) using our glyconanoparticle platform. With our partners at Iceni Diagnostics and UHCW (Coventry Hospital) we integrated this into a flow-through device - similar to a lateral flow device - where the sample is dried, rather than captured on a test line. Using this, we show that primary swab samples of positive/negative patients can be identified correctly by this technology, and demonstrating the principle that rapid (eg lateral flow) devices that currently use antibodies as the detection agents, can be modified to use glycans instead. We also show that the spike proteins from variants of concern can still be detected in this format. Whilst still a prototype and this shows that glycan recognition can be deployed for infection monitoring and we are actively pursuing this technology.
Press release here. https://warwick.ac.uk/newsandevents/pressreleases/alternative_to_antibodies
Toward Glycomaterials with Selectivity as Well as Affinity
Our perspective article on glycomaterials has been published in JACS Au. Glycans (sugars) coat the surface of mammalian cells (the Glycocalyx) and >50 % of all proteins are estimated to be glycosylated. These glycans provide a vast range of roles, such as 'markers of self' and as sites for pathogen adhesion. Presenting glycans on polymers, particles or surfaces is an appealing means to mimic/interfere with these processes, and due to the cluster glycoside effect, displaying lots of glycans on the same scaffolds leads to remarkable enhancements in affinity, which has been widely studied. This perspective discusses examples where selectivity, as well as affinity has been introduced into materials. Most current glycomaterials show high affinity, but will bind a wide range of protein targets (such as lectins), but we summarise how materials-solutions can be deployed to selectively target one protein, over another, even when they 'like' the same glycan. This is crucial if glycans are to be deployed in sensing, and other application areas.
Read the paper here!