We have a major research interest in how we can develop new materials, inspired by extremophiles, which can bind or modulate ice growth and also macromolecular cryoprotectants to protect cells/proteins from cold damage. A key challenge is that discovering new materials which affect ice growth is challenging (compared to the well known ice binding proteins). In our latest paper we report that polymer nanoparticles, derived from PISA (polymerization-induced self-assembly) had the surprising property of preventing ice recrystallization (growth). What was surprising was that the coronal polymer (water soluble outside parts) alone had no activity, but in the PISA particle format showed a remarkable enhancement, with larger particles being more active than small. One polymer, polyvinylpyrrolidone, appear to bind ice crystals when in particle format, which has not been previously reported. The results are really exciting as these are really very easy to synthesise and a huge range of monomers and particle morphologies can be accessed and will let us explore these properties. We also showed these polymers do not nucleate ice formation, as few materials do. This was important as large assemblies of ice binding proteins have been shown to nucleate ice, but that was not seen here.

The paper has been published in the Journal of the American Chemical Society, read here -

Polymer Self-Assembly Induced Enhancement of Ice Recrystallization Inhibition

Our work, to develop a new approach for SARS-COV-2 (virus which causes COVID-19), and other pathogens, has been featured in a University feature on impactful research. For the past year many member of our group changed their research focus to help develop an understanding of how this virus binds glycans (sugars) which gives insight into its infectivity, but also provides an opportunity for new diagnostics. We will be releasing more news on this exciting project soon.

See the video here

read our paper on the topic here

We have a vacancy for a post-doc to be based in our labs in the medical school. The candidate will join our team working on the cryopreservation of complex cell models including 2 and 3D monolayers and exploring their use in toxicology screening.

Full details and links to application are here.

Our Spin-out Company, Cryologyx, has secured additional investment and closed its first investment round. This goes alongside a large grant from Innovate UK. Cryologyx is a biotechnology company aiming to bring new cryopreserved products, and underpinning technologies, to market and is led by former PhD and PDRA Dr Tom Congdon.

Read the press release here.

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