Our latest collaborative work lead by the Sosso Group has been published in Nature Communications. We have a long standing interesting in how synthetic polymers can be used to control ice crystal growth. Even after several years of study, the most active polymer for ice recrystallisation inhibition (IRI) is still PVA (poly(vinyl alcohol)) and exactly how it is so effective was not clear. In recent years it has become clear the PVA hydrogen bonds to ice, and previous studies suggest it can form a 'ladder' like lattice match onto the ice. In this work, atomistic simulations were ran which show that the size of the PVA coil (as polymers are not fully stretched our molecules - 'cooked not raw spaghetti') was a crucial descriptor of activity. It was seen that short PVA chains (which have less IRI activity) actually bind the ice as well as longer PVA chains (which are more active) but they cannot stop ice overgrowing it so well. These results will help us design new more active materials whilst adding to our fundamental understanding of these interfaces.

Read the paper here

he atomisic details of the ice recrystallisation inhibition activity of PVA

It is well known that cationic polymers can disrupt cell membranes, most famously for disrupting bacterial membranes which are 'more anionic' than mammalian. However, these polymers can be used to kill cancerous cells, but avoiding non-specific toxicity to healthy cells and blood cells is a major problem. Most work in this field involves making minor changes through co-polymerization in the hope of making the polymers more specific. In this work, we instead engineered the cancer cells to 'capture' the polymer. We used metabolic oligosaccharide engineering to install azide groups selectivity on cancer cells, or cancer spheroids, and using alkyne polymers we could 'guide them' to the cells. This lead to increased toxicity and hence a wider therapeutic window. We showed this with several cell line and spheroids and also showed the covalent targetting induced additional mechanisms of cell death.

Read the paper here in Chemical Science

Covalent Cell Surface Recruitment of Chemotherapeutic Polymers Enhances Selectivity and Activity

The new company Cryologyx has been formed, supported by a grant from InnovateUK. Cryologyx will use technology developed in our laboratories to transform how cells are frozen, and distributed. The company will be led by (soon to be former) postdoc Dr Tom Congdon, who will be CEO. Keep watching for more updates!

www.cryologyx.com

Ola Alkosti has joined the group as a PhD student. She will be working on cell-surface labelling technologies, seeking to covalently modify cell surfaces to introduce new functionality, as an alternative to genetic techniques.

Read more about Ola and her research here

Qiao Tang has joined the group as a PhD student in January, on a prestigious Chancellors International Scholarship. Qiao's research will explore the biomedical application, glycan metabolic labelling and its use to capture synthetic nanomaterials and polymers.

Matt has been awarded the 2021 McBain Medal from the Society for Chemical Industry and Royal Society of Chemistry. This award is to "honour an early career researcher or technologist who has made a meritorious contribution to colloid and interface science." Matt was particularly pleased that he can still be called Early Career. There were will be a special symposia late in 2021 where Matt will receive the medal and give a lecture.

This medal represents the massive contributions of past and current team members which are too numerous to list. Thanks go to UoW and both Department of Chemistry and Medical School for allowing the GibsonGroup to spread their work over both Departments.

Matt is the third member of the Chemistry Department to be awarded this, after Julie Macpherson and Rachel O'Reilly.

Glycans (aka sugars, carbohydrates) direct many recognition and signalling processes in biology. Multivalency (presentation of lots of copies) is crucial to overcome glycans intrinsic low affinity, hence materials (polymers, particles, surfaces) which display them are appealing probes of function, or as new diagnostics (e.g. see our work on COVID diagnostics). However, most studies use simple monosaccharides, which may not have selectivity or are only tested against plant proteins. In this work, we collaborated with teams from Bristol, York and Southampton - our collaborators developed a chemoenzymatic synthesis to obtained selectively fluorinated glycans based on lacto-N-biose. Fluorine is appealing as it is small, does no have significant effects on conformation, but can change hydrogen bonding patterns. These glycans were incorporated into our polymer-stabilised nanoparticle platform, and found to modulate the affinity towards 2 galectins -an important class of galactose-binding biomarkers. This work shows that unnatural glycan-functional nanoparticles could be deployed as biosensors.

Read the paper here;

Introducing affinity and selectivity into galectin-targeting nanoparticles with fluorinated glycan ligands

There is a real need to modulate our immune systems to help treat cancer, autoimmune disorders and allergies. One of the key cell types in immune responses are dendritic cells. There is particular interest in how dendritic cells interact with, and respond to glycans (sugars), which is a key process during e.g pathogen recognition. In this work we developed surfaces bearing different monosaccharides, attached via a polymeric tether and our collaborators at Nottingham University investigated the impact this had on dendritic cell function. The strategy was crucial as no soluble additives were used, so the signalling was purely from the cell/solid interface, and hence would show if a material can be used to tune DC cell function. The key results were that specific combination of glycans could suppress dendritic cell activation implying an anti-inflammatory or regulatory phenotype.

Read the paper here

Developing immune-regulatory materials using immobilized monosaccharides with immune-instructive properties