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Wed, 28 Jun 2023 12:55:12 GMT

We are porting our webpage to our new site. This is still being developed but will fully port over summer 2023.

Extracellular Ice Nucleation Improves 2/3D Cryopreservation by Preventing Intracellular Ice

Fri, 28 Apr 2023 09:21:27 GMT

Working with Dr Tom Whale (Chemistry) we have demonstrated how controlling ice formation outside of cells can help reduce intracellular ice formation, during the cryopreservation of monolayers and spheroids. During cryopreservation in low volumes, water can supercool (i.e not freeze at zero), which means cells are exposed to supercooled liquid water which leads to increase intracellular ice formation, which can be fatal. The team used extracts from pollen, known to nucleate ice at warmer temperatures, to prevent supercooling and show this reduces the amount of ice inside cells. Due to the the cryopreservation of the cells, in both monolayer and spheroid format, was dramatically improved. This method is appealing as it only involves changing the the solution outside of the cells, to mitigate an intracellular process, rather than delivering a new cryoprotectant into the cells.

Chemically Induced Extracellular Ice Nucleation Reduces Intracellular Ice Formation Enabling 2D and 3D Cellular Cryopreservation

https://pubs.acs.org/doi/10.1021/jacsau.3c00056

Polymers which prevent phage infection of bacteria

Wed, 19 Apr 2023 08:10:00 GMT

Bacteriophage (phage) are present wherever their bacteria hosts are. Phage have huge biotechnological potential, but lytic phages can also cause complete loss of bacterial cultures. For example in the food industry, or in ever research laboratory where rigorous sterile handing is the primary containment strategy. For industrial biotechnology using microorganisms to enable sustainable of chemicals, materials and drugs, phage infection must be addressed. In our latest (patent pending) work, in collaboration with the SagonaLab at Warwick, and Cytiva, we discovered that a simple polymer can prevent phage infection of bacteria when applied to the growth media. This process is simple, requires no change to working practises and prevents phage infections. We are still investigating the mechanistic aspects, but this is virustatic (inhibitory) rather than virucidal.

Read the paper here

<em>Anionic Synthetic Polymers Prevent Bacteriophage Infection</em>

Read press release here

Poly(proline) as a bio-sourced ice recrystallisation inhibitor published

Mon, 17 Apr 2023 15:14:00 GMT

Ice-binding proteins (IBPs) from extremophile organisms can modulate ice formation and growth. We are very interested in developing polymeric mimics of IBPs as a route to understand their function and to deploy in various applications, from mitigating freeze–thaw damage in concrete to frozen food texture modifiers, to cryopreservation of cells and tissue. We have done much work on vinyl-based polymers, but it is, however, desirable to use biosourced monomers and heteroatom-containing backbones in polymers for in vivo or environmental applications to allow degradation. In our latest paper, in collaboration with the Heise Group in Dublin, we show that high molecular weight polyproline as an ice recrystallization inhibitor (IRI) and provide evidence that it can bind ice crystal faces. This work shows that non-vinyl-based polymers can be designed to inhibit ice recrystallization and may offer a more sustainable or environmentally acceptable, while synthetically scalable, route to large-scale applications.

Read the paper here

High Molecular Weight Polyproline as a Bio-Sourced Ice Growth Inhibitor: Synthesis, Ice Growth Inhibition" Link

Poly(vinyl alcohol) and Ice Nucleation in Microfluidics Published

Mon, 17 Apr 2023 15:10:54 GMT

When does an ice binder become an ice nucleator?

The formation and growth of ice is crucial to our climate, food security and delivery of advanced therapies. Ice binding proteins (IBPs) can both stop ice growing (‘antifreeze proteins’) or nucleate it (ice nucleating proteins), but when an AFP becomes an ice nucleating protein is not clear? The GibsonGroup, working with an international team of collaborators, have shown how a synthetic polymer mimic of an AFP can nucleate ice, as a function of the size of the polymer. This was achieved using a series of very sensitive microfluidic ice nucleation measurements. The work is important as it makes progress towards how ice nucleators can be deployed for areas such as cryopreservation, where supercooling of water (i.e freezing at very low temperature) is a major challenge.

Read the paper here

Ice nucleation in aqueous solutions of short- and long-chain poly(vinyl alcohol) studied with a droplet microfluidics setup

https://aip.scitation.org/doi/10.1063/5.0136192

Identification of Protein Glycoforms using Nanoparticles is Published!

Wed, 18 Jan 2023 10:34:00 GMT

In the diagnosis of disease, proteins are common biomarkers. These are typically detecting using antibodies which specifically target protein sequences, such as those used in lateral flow devices (LFDs). However, there is a challenge in that any given protein sequence can have many different post-translational modifications - phosphorylation, lipidation and many more including glycosylation - the addition of glycans. The presence of a particular protein (detected by antibodies) does not always indicate disease and the exact glycoform is an important parameter not detected by current biosensing strategies, requiring complicated methods or technologies such as mass spectrometry. In this work, we show a hybrid detection based on antibodies and lectins - glycan 'reading' proteins. We use the antibody on the surface of a biolayer interferometry sensor to first capture 'all proteins which match' the antibody, but they use lectin-coated gold nanoparticles as the signal generators, so that we only detect a single glycoform. We demonstrate this with prostate specific antigen (PSA), where the different glycoforms, not just protein concentration, are important markers of disease.

Read the paper here, published in Nanoscale Horizons

Discrimination between protein glycoforms using lectin-functionalised gold nanoparticles as signal enhancers

New Method to Cryopreserve 3-D Tissue Models Published in ACS AMI

Mon, 09 Jan 2023 09:11:00 GMT

Cell culture enables the study of biological process and the discover of new drugs and biomaterials outside of the body. However, culturing cells in 2-D is not always predictive of what cells do in 3D (inside the body). There is a need to make 3D cell models (which are harder to prepare) to enable predictive screening to predict outcomes in the body, without (or before) resorting to animal models. In our latest work we have developed a method to cryopreserve spheroids - 3-D assemblies of cells which are more predictive of physiological outcomes than normal 2D monolayers. We achieved this using our macromolecular cryoprotectants which mitigate cold damage by mechanisms that traditional cryoprotective agents dont address. We show that liver-cell spheroids can be recovered in high yield, are healthy and respond to drugs (i.e. toxicity testing) the same as fresh spheroids.

This work is important, as spheroids are known to be more predictive than 2D cell monolayers but the barrier to researchers to use them is high, developing the techniques and handling of the cells. By developing this method to freeze them, the spheroids can be prepared, banked and easily shared as a frozen product. This work was conducted in collaboration with our Biotech spin-out Cryologyx Ltd.

Read the paper here

Cryopreservation of Liver-Cell Spheroids with Macromolecular Cryoprotectants

A Bottlebrush-Shaped Polymer Which Can Nucleate Ice Published

Tue, 29 Nov 2022 08:31:54 GMT

We have a major research interest in understanding, and deploying, ice binding protein mimetics. Whilst we have made huge progress with polymers which can slow the rate of ice growth, the question of how to make ice nucleate remains a challenge. Ice nucleating proteins form complex assemblies and isolated proteins are poor nucleators. To address this, we have synthesised dense bottlebrush polymers with poly(vinyl alcohol) side chains. These side chains are known to bind ice and when presented as very high molecular weight (100's of kg/mol) we show they can nucleate ice. This is the first report of a bottom-up designed polymeric nucleator which we can now use as a tool to probe ice nucleation.

Read the paper here

Poly(vinyl alcohol) molecular bottlebrushes nucleate ice

Optimisation of glyconanoparticle outputs published

Tue, 22 Nov 2022 10:02:52 GMT

Our latest work, from Mchem student (now PhD at Birmingham) Julian has been published in RSC Advances. We have a long standing interest in using plasmonic (gold) nanoparticles in biosensing. For example, during COVID we used our nanoparticle platform to identify glycans which the spike protein binds to. One useful feature of gold nanoparticles is their colour change (red to blue) when they aggregate. We have developed technology to install glycans using polymeric tethers to the gold particles allowing 'easy' deciphering of if the glycans are binding their protein partners by simple colour changes. In this latest work we set out to make a 'recipe' that a new user can follow to let them use our system in their own lab. This involved finding the optimum size, polymer length and crucially concentration of the gold to minimise false positives/negatives. We hope this paper is useful to other users who are interested in this tool.

Read the work here

Polymer-Tethered Glyconanoparticle Colourimetric Biosensors for Lectin Binding: Structural and Experimental Parameters to Ensure a Robust Output

2023 PhD vacancies now open

Fri, 21 Oct 2022 07:27:00 GMT

We are not beginning to advertise our (fully funded) PhD openings for 2023 start. These span polymer chemistry, glycobiology, cryobiology and diagnostics. We apply these tools in important areas of sustainability, new healthcare materials and more.

More here

https://warwick.ac.uk/fac/sci/chemistry/research/gibson/gibsongroup/vacancies/