Small structures from soft matter | 91TV
Transcript
- If you'd like to take a seat,
- we can start this evening's proceedings. First of all, my name is Sheila Rowan. I'm
- the physical secretary for the Royal Society and it's my pleasure to welcome you to this evening's
- lecture. Before we start, just a few housekeeping reminders. Please could you make sure that your
- mobile phones are switched to silent. There are no planned fire evacuations. So in the event of the
- fire alarm sounding, please do vacate the building via the nearest fire exit, and the assembly point
- once you are outside the Royal Society is at the top of the Duke of York steps to the right as you
- go out the building. I am pleased to say that there will be an opportunity to ask questions
- at the end of the lecture this evening, so you can be thinking of that as we as we go
- along. The Clifford Paterson Medal and Lecture is given for outstanding contributions in the field
- of engineering. The lectureship was originally endowed by the General Electric Company in memory
- of Clifford Paterson, FRS, who founded the GEC Research Laboratories in 1919. Tonight's lecture,
- entitled Making Small Structures from Soft Matter to Create New Frontiers, will be
- delivered by Professor Mohan Edirisinghe, winner of the Clifford Paterson Medal and Lecture 2024.
- Professor Edirisinghe holds the Bonfield Chair of Biomaterials in the Mechanical Engineering
- Department at University College London. He has published over 600 journal papers and over
- a dozen key patents, given more than 125 lectures worldwide. Professor Edirisinghe has been awarded
- many grants to explore novel avenues of scaled up forming of advanced materials for application in
- key areas such as healthcare. In 2015, he was elected as a fellow of the Royal Academy of
- Engineering in the UK. In 2020, he was elected a fellow of the European Academy of Sciences,
- and in 2021 he was appointed OBE, Order of the British Empire for his services to biomedical
- engineering. Ladies and gentlemen, I am very pleased to present Professor Mohan Edirisinghe.
- Thank you very much, Professor Rowan, chairperson. Ladies and gentlemen,
- thank you very much for coming along, and the Royal Society, thank you very much for
- selecting me for this splendid opportunity. I used, as my title, the full citation that was
- given to me very kindly by the Royal Society, and I only did that because I want to emphasise the
- fact that the short title is fine for social media consumption, etc., etc., but those words, novel,
- scalable ways is a very, very key matter in this whole operation in my laboratory. The reason for
- that is I look at processes that can mass produce, that can manufacture, not only in the lab,
- but there must be the provision to scale down to a point of care scenario or scale
- up so that the engineering industry can select it and use it, if they so wish. I will start off in
- a very maybe unconventional way. Most people put this at the end, but I like to make this the start
- because I owe it to a lot of people for being able to stand up here. In particular, I'd like to thank
- very much UCL, UCL Engineering, and UCL Mechanical Engineering. The Mechanical Engineering Department
- at UCL has given me a splendid home where I could be happy and also be very productive, and I'm very
- grateful for that. Thank you very much. Then there comes a whole host of people and a whole host of
- organisations and countries that have really gone on to help my research, and also, I want to thank
- the Royal Society for their splendid work to put this lecture together. All these people,
- particularly Harry Carnham, who was very, very supportive and did a lot of work to get this
- all sharp and correct. I'd like to make a special thank you, it's quite unavoidable that if you're
- engaged in research for, say, two decades or even a bit more, that you end up with two families, the
- biological family at home and the research family at work. They've both been extra supportive to me.
- Of course, the biological family is quite small, but the contribution they have made
- or they are making to the NHS, I will never be able to match, and for those who know them, will
- understand what I'm talking about. The research family at work has been very productive and very,
- very supportive. I have come through many organisations and universities. Each time,
- I have had great support in people supporting me and introducing me to others, so on and so forth,
- and this really has been a worldwide scenario. I have this ideology, whether it's right or wrong,
- that if there's a theme, I like to have people, you know, from undergraduates, MSC students,
- some PhD students, postdocs, and even academics coming on to that project. That has been a very
- successful thing, in my opinion, and I have been able to formulate teams on that basis. Some of
- them, the undergraduates themselves, have been very productive publishing papers, I will make
- a couple of examples of this, and also they have been able to draw in even A-level students who are
- keen to take up this kind of research activity. I'd like to thank my funders and collaborators.
- In particular, I would like to thank EPSRC, at the last count, I've had 40 odd grants from them,
- and also the industry, in particular BASF, who has supplied many, many materials for me. I would also
- like to thank the collaborators within UCL. I have a lot of collaborations here. I will mention the
- UCL School of Pharmacy in greater detail later on, but I'd also like to thank others in the UK
- who have really help me across. I believe that the most effective way in doing research is to
- have the complementary expertise coming together. That is something I very sincerely believe in,
- and sometimes I extend that to the rest of the world as well. Now my current laboratory is a bit
- different to what you're seeing. It has two small sectors on either side of a corridor, and these
- two sectors do research on spinning and on actual electrohydrodynamics. I would like to thank,
- before I forget, the UCL Mechanical Engineering Workshop that has really gone out of their way to
- help me design devices, to scale them up and scale them down whenever necessary. That has
- been a very, very important issue. Today's lecture will mirror that electrohydrodynamic and spinning
- operations on either side. I was in a dilemma. How do I present this one to two decades' work in 45
- minutes? Not easy. Can I go into some projects and go down in detail, or do I take and show
- the entire volume of the operation? I selected the latter. So this invariably means that I will
- miss out on some of your many contributions that have come to me and I do apologise right at the
- beginning. I will take snapshots from history. When I was a student at Leeds, I was told, don't
- dwell on history, but reflect on and off, and that's not a bad thing. I would also take examples
- from the present, and I will also take examples of the future pointers. I look at the scenario like
- this. Now as of coincidence, not done in any other way, this book was released by IOP in February
- 2024, and it has a big section on the kind of soft matter materials that I'm going to talk about,
- particles, capsules, microbubbles and fibres. IOP invited me to do this book two years ago.
- It has taken a lot of time, maybe, but I teamed up with two other collaborators, Professor Merve
- Gultekinoglu from Hacettepe University in Turkey, and my own Dr Jubair Ahmed to produce this book.
- It's available in hard copy, any copy, and I won't be able to go into all the details of this here,
- but that is going to be something that I will point out for future reading. Now let's look at
- microbubble preparation. What have I done? The most of this work I did in collaboration with
- Professor Eleanor Stride, with whom I published nearly 100 papers, but when I joined UCL,
- we had two methods, sonication and T-junction microbubbling. We thought, let's think outside the
- box, and we invented coaxial electrohydrodynamic microbubbling. Very simple idea. You have a
- solution flowing through a needle or a nozzle, and you apply an electric field at the edge of it, but
- we modified that to have air flow in the centre and the solution flowing on the outside and we
- got a very good response. We couldn't quite match the monomodal, near monomodal distribution of the
- T-junction, but we were getting closer and we were able to match and model the process into three
- modes, the bubble dripping mode, the actual coning mode, and the actual microbubbling mode that you
- see happening here. So electrohydrodynamic microbubble preparation gave me and Professor
- Stride, and the researchers involved, a lot of pleasure, and were able in the kind of Ashby
- philosophy to map the process and work out what rates are necessary to control the bubble size. If
- you are going to use these bubbles in biomedical experiments, you've got to have monodisperse and
- from about two to five micrometre diameter. You've got to also have them of long life and
- also then have easy and high yield production. They are not easy things to achieve. We also,
- and I see her in the audience, did a lot of good work with Mariam Parhizkar, who was one
- of my PhD students but now a lecturer in SOP at UCL, and she came up with the idea, okay, that's
- the actual conventional T-junction microbubbling scenario. Why not combine the electrohydrodynamic
- with that and have a scenario where you apply the electric field at the tip of the T-junction? That
- paid dividends because we were able to control the size, also make the production of those little
- bubbles much, much faster, as you can see. Now I will be going through many, many slides in this
- presentation. I have no option to give you that volume effect of the work over one to two decades,
- but the detail will be always in the slide and also the references, the relevant references
- are given below. Now this gathered interest because more recently one of the research
- students, Anjana Kothandaraman, working with Professor Tony Harker, who is one of my very,
- very good friends through the statistical and analytical input for this work, and Professor
- Yannis Ventikos, then imposed not just a DC field at the edge, but an AC field at the edge, and that
- did also improve, I don't have the time to go into the detail, the bubble production and control and
- yield did increase. The electrical engineers at Queen Mary got very interested in this,
- and a lot of good academic work was done on this basis. Now, we have gone back to the T-junction,
- sometimes in science that happens. You go on a tangent, you discover new things academically,
- someone might pick it up 100 years later, as has happened in more famous inventions,
- but you sometimes revert back, and that is because the industry or the user is telling,
- I like the fancy science, but I also want scaled up production. So what we did was without having
- one junction, we had two, three, four junctions, and we have the capability in the laboratory today
- to couple four T-junctions experimentally. That is a big jump because the engineering here is a
- little bit complicated. This is the excellent work of Bing ji Wu PhD student. We are now able to say,
- by controlling these parameters that we will get this bubble size. We will also get it in
- higher yield and also higher lifetime. We have a very good collaboration, they invited us,
- ACS Langmuir, American Chemical Society is a very well-known journal, historically sound,
- and they asked us to do a special issue on this topic, Microbubbles, a New Medical Frontier. I
- now have two new collaborators because they are interested in this coupling of the microfluidic
- junctions, and we have Professor Sameer Dalvi, who is a chemical engineer from India,
- and also one of my former PhD students who is at Marmara University, Professor Oguzhan
- Gunduz collaborating. Since that special issue, we have published a lot of papers verifying
- various aspects of microbubble preparation. I think the one I like was this one because it
- had authors from several countries, very leading people, and we were able to, as the topic says,
- prepare lifetime enhanced microbubbles that were stable because we were able to incorporate silicon
- quantum nanodots in the microbubbles. I will leave bubbling there, but I can go on until Christmas if
- I'm talking about microbubbles. We have also a similar scenario now with actual particles.
- So we use the electrohydrodynamic technology not only to make bubbles, but also to make particles.
- Now we have the ability to say, right, these are the particles that you want of this biopolymer,
- this is the size distribution that you want. We will couple together the solvents and prepare
- the sizes that you want. I've been delighted to have the support of Professor Shervanthi
- Homer-Vanniasinkam, a clinician, and also our own Professor of Engineering and Surgery. She has
- taught me a lot of lessons and my researchers to think about the clinician and the patient right at
- the start, and not to leave it until the very end, and we now pursue this kind of advice in designing
- our projects. I do think that the cream of the particle preparation work came here in 2014,
- where we were able to put together the world's first device, where we have four coaxial nozzles
- performing electrohydrodynamics, and what more, giving a four layered particle with four different
- polymers, all that can be attached to actual active pharmaceutical ingredients. This was picked
- up as the front cover of Macromolecular Rapid Communications and also won the Venture Prize,
- went on to form, through UCLB's very generous support, AtoCap, a spin off company which is now
- run by others. I'm very grateful to Alex Pitt of Mustard Seed, who has done a lot of work to bring
- it up to this level. I'm also very grateful to Jenny Rowan, UCL Professor Jenny Rowan, who has
- done much of the microbiological work for this. So this is an opportunity we thought to scale down.
- This is a device currently available in my lab. It has gone through many generations but this current
- device has that four nozzle needle capability, but on a very small handheld device. This was
- work I did with Professor Duncan Craig when he was at SOP, School of Pharmacy, but I think what Dr
- Francis Brako and Dr Chao J. Luo, two postdocs that worked with me, have developed is a very,
- very powerful tool because we can take this to a site and prepare the kind of particles that
- is necessary, and much more. Another piece of work on the electrohydrodynamic front is
- this particular piece of work. We do that in collaboration with Medway School of Pharmacy,
- University of Greenwich. The topic is progesterone and we are making patches using progesterone,
- and I see Dr Omar Shafi, who just graduated from the team from UCL, PhD student, and if
- enough is not enough, he is very passionate about this and he has gone on to do medicine
- now. So he's a medical student starting in the first year, another five or six years of study,
- but he has come up with two patches. I won't talk a lot about them because one of them is
- going forward to maybe a patenting scenario, a PCL fibre patch that gives progesterone release,
- but also, more importantly, a hydrogel patch, which we think is more promising. So that work,
- I think Omar has the blessing of the clinicians and he will take it forward in any which way he
- can. He's a very passionate guy when it comes to treatment and patients. We also have two projects
- which I must mention. This is the work of a PhD student, and the first one is done with Oxford
- in collaboration with Dr Tanveer Tabish, who to me is a real expert in practically implementing
- graphene structures. He can make graphene in many ways, and the graphene oxide is very,
- very powerful in killing bacteria, viruses, and also against fungal scenarios. This work is now
- going into more serious, deeper, and we were asked by Advanced Healthcare Materials to review
- the possibilities of using graphene, which we've done forms of graphene, and I look forward to this
- work developing with Tanveer. What more, earlier this year, through an MSC project, we were able to
- stumble on a patent and we used UCLB to evaluate it and they agreed that the idea of hydrogen
- sulphide releasing composites for bacterial wound dressing has some commercial mileage. So that is
- already patented and a number issued. Now there is also another project that is developing. I
- love these collaborations because it gives you the opportunity to tap into complementary expertise,
- with Dr Ishara Dharmasena of Loughborough University. He's an expert on TENG devices,
- triboelectric nanoengineering devices, and we have the work of SEDA developing biosensors, nanofibers
- to use as biosensors at the moment. This is quite mature. This one has just about started. So what
- we want to do is to combine the two. My role in the lab is to make the morphologies that you
- want with the graphene oxide placed wherever you want on a fibre using electrohydrodynamic methods,
- and we want to combine the two to make a single nanofiber for self-powered biosensor activities,
- that I think will be something that we look forward to, the collaboration with Dr Ishara.
- We also have a new project, EPSRC supported, and appropriately it's named SANTA because
- SANTA has come very early, this has only started, and the PhD student running it is
- a very dedicated researcher who puts in a lot of time. We run this in collaboration with the
- School of Pharmacy, Dr Mariam Parhizkar, and also my good friend, Professor Anthony Harker,
- who gives us advice on the more analytical side of things. Electrohydrodynamics is easy when you
- read it on the surface, but it involves many, many variables, flow rate, applied voltage, distance,
- if you want, many physical properties, and this has to generate reams and reams of data. We
- want to put that into some kind of combinatorial library. That is being achieved at the moment. Two
- recent publications from us demonstrate that, only to a certain extent, but I think this particular
- operation is the more important one, because whether we like it or not, we have to think
- about the environment. We have to think about others using it. We have to think about laboratory
- safety in an enhanced sense, and what we hope to do, by following this rule of a G-score,
- which is a solvent sustainability score, and also using an E-score, which is an energy score,
- to come up with actual new solvents to replace the bad ones. When I call them bad, I never like
- to call anything bad, but the ones that are more recognised as dangerous, like DMAC and chloroform.
- We want to eventually replace them with better and better solvents so that the process itself can be
- carried out in a very safe and active way, because when you take these things to industry, that
- is one of the big questions that people will ask you. So the scale up factor here is very important
- when we take this message to the industry. I will now dwell on a topic that I'm passionate
- about. This is a process we invented by chance, maybe. We were alerted to the fact, in 2013,
- that the world requires the ability to produce fibres from polymeric materials at a larger scale.
- Electrohydrodynamic spinning is a good one and can be enhanced as well, but of course we want to
- do this in a very simple way where the fibres are gushing out in unlimited amounts, and then you can
- collect it very easily. Here, we have the scenario where we have a simple pot. It's got orifices
- around the centre of the pot. We quite do not know why we put it there. One of the new PhD students,
- Ahmed Al Nadi, who has just started in the team, is going to look at this. Where are the holes
- that need be placed and where and what size, but it gave us good yield. Doctor Mahalingam,
- who was a postdoc who started this off, produced some very good results which we were able to then
- take to EPSRC. In fact, in this area, we have won three grants, and all what you see here and
- I'm surprised by this myself, up to 2023, ten years, are the front cover pages that editors
- have selected, when we publish a paper on this, to be highlighted. There were some fascinating pieces
- of work. I will come to this bubble making through gyration later. It's a form of pressure spinning,
- but what differentiates it from actual centrifugal spinning is that you can rotate the pot and
- at the same time apply pressure. Now Kansas University, my good friend, Professor Tamerler,
- who looked at this process, said, I am interested in using the process to alloy the fibres, if you'd
- like to call it that, with actual peptides. She was of the opinion that without pressure,
- a better variable may be the flow rate into the vessel. So we investigated that and that came up
- trumps, very, very good results from that, and we are also able to do this without a solution.
- Solutions are not the favourite things when you go to industry, not to use in large quantities,
- but here we use it through the melt and many other changes have come across here. This is
- a piece of work we did with China and America, shape memory fibre, that's using the pressurised
- gyration process, and this particular two papers, Journal of the Royal Society Interface,
- followed by the proceedings of the Royal Society, The Engineering Journal, where we have used, this
- one we call pressure coupled infusion gyration. We have all the variables that we can look at,
- and here, we showed that you can alloy these fibres in that small mixing pot with, let's say,
- graphene or graphene oxide, this is the work of Dr Ruby Mantaro, who was also a PhD student
- in my team, in very great force. It destroys bacteria very, very well at the right loading.
- The real crunch on this has come in 2020 where we thought, why waste all this active material
- inside a fibre? We should go for core sheath fibres, where the core retains the strength and
- the sheath retains the actual active material. So core sheath pressurised gyration, which is rapidly
- becoming a very common name, has been developed, and Dr Mahalingam did it with a very simple setup
- where he had two chambers rotating in each other. The real upsurge came with the work of Dr Hussain,
- who was a PhD student who passed out two years ago. He was able to show that you can do this
- in a very portable device that is also capable of handling any kind of polymer. The American
- Institute of Physics took this up very, very quickly. There was a skylight launched on this,
- and he was able to show that these fibres can be produced quite well and easily and with control.
- So I'm very grateful to Hussain, who works for a manufacturing department, and he, in my thinking,
- is the real pioneer to core sheath pressurised gyration. He's going to take it further. The
- last part of his thesis was on making a device or a vessel that can handle more than two layers,
- maybe three. The equipment is ready and we are going to make that useful in Kuwait, where his
- labs are now, ready for investigation. So we look forward to that work in collaboration. We also
- now have a large emphasis on the environment. Remember, polymeric materials, whichever way
- you look at it, and solvents and actual fibres are not very welcome in the industrial world or in the
- public world, especially. This work started by Dr Jubair Ahmed and we had the fortunate scenario of
- Alesha Kelly coming down from the University of Chicago for two summer stints to develop
- this. This is the use of cyclodextrin, both using electrospinning and gyration, and we were able to
- develop the concept of an actual super match, where the two are fibre making methods met. We
- were asked to review the process, which we've done in 2023, but when you review something, you always
- get an upsurge. There is some other way of opening that comes through to tell us, and when I finish
- this lecture, I will be able to give you a better insight into what is really going on. So we have
- developed through the pressurised gyration work, very close collaboration with School of Pharmacy,
- firstly with Professor Duncan Craig, then Maryam Parhizkar, and now Professor Gareth Williams. I
- only say this because a few weeks ago when I went to the School of Pharmacy, and I didn't know this,
- the second floor corridor from end to end consists of gyrated fibres. So I thought that was a very
- nice advert. They cherished the presence of that. I do also think that the underexploited
- process is the making of bubbles using gyrated fibres. This is some work that Langmuir thought
- was very potent, and we were able to make bubbles, coat them with the right materials,
- and also then destroy bacteria as you can see. This work, gold nanoparticle containing
- PVA lysozyme microbubbles is a very effective paper, and we are still to exploit that because
- we've been diverted by many other areas that have taken precedence. What is very important to note,
- and this I want to tell this audience, and please go and spread the gospel on this, I am not a
- selector of processes. Although pressurised gyrations pressure spinning is our process,
- I don't want to say that electrospinning is lesser in one sense or form. I always, in selecting a
- process, will consider both. Sometimes you will get electrospinning as the more powerful method,
- sometimes pressure spinning, and we always compare this. Dr Ahmed started this comparison. I am not
- showing the slide because of lack of time. He started the actual comparison scenario,
- and if you make drug delivery fibres using this kind of scenario, you will have the pressurised
- gyrated fibres retaining the active pharmaceutical ingredient for a long time. So you will have no
- release, and then rapid release, burst release. On the other hand, if you select electrospinning,
- you might have the sustained release that you want on some instances. Now, you can combine this, and
- this is the most recent paper. Qosim is one of our new PhD students, if you'd like to look at that,
- but he's taken like a duck takes to water, the work, and with me and Professor Williams,
- this is one of his very first papers in cellulose, published under the very watchful eyes of the
- editor in chief of cellulose, who basically checks every paper in a sense that comes to him. I'm very
- grateful for his comments and improvements. We also have a special piece of work with North
- Dakota University, Professors Kalpana and Dinesh Katti. We talk to them using Zoom very often and
- they produce very viscous materials, this nanoclay with hydroxyapatite in it is a very, very viscous
- material. They've been unable to get fibrous materials with the hydroxyapatite dispersed
- for a very long time. They came to us and we tried the gyration route, and we got a very,
- very good dispersion, and that work is really published in Composite Science and Technology,
- but also, we are now moving that forward using a core sheath scenario where we will put their
- active material in the sheath. Now for gyration, the sheath comes out to a very small number,
- nanometres compared to the core. Why that is, we still don't know completely, but we are out
- to find that out, and that is an advantage, a blessing in disguise, because if the active
- material that is more expensive is on the sheet of the fibre, and if you can get the same effect or
- even an enhanced effect, that is a bonus. They are going to use the core sheath fibres with
- their additives for bone tissue cancer treatment, which they think is at a very advanced stage. We
- also have a very, very fruitful collaboration, starting with Professor Ipsita Roy. Professor
- Roy is one of the world's leading experts on polyhydroxyalkanoates, a special polymer,
- and I think independently, a polymer that might have a lot of mileage, for the simple reason
- that it is produced in a more environmentally friendly, efficient way. Now, we were given a
- sample of it and told to produce structures that are probably attractive to different
- types of cell culture. We did that. We got a lot of fibres aligned in one direction. We got
- a lot of fibres with porosity on the surface, we know how to control those, and then we were able
- to send them to independent centres, the fibres that were produced, cardiac at Imperial College,
- bone at Southampton, and nerve at Sheffield to assess and the results are promising. Again,
- here, we are moving to the core sheath fibre formation front. Now the actual core sheath
- work is progressing at a rate that I can't even sort of rein in on. We have Hamta Majd,
- a senior PhD student, also the Maryam Mirzakhani Scholarship winner in 2023, taking it forward for
- the use of drug delivery. She has demonstrated the effect in a paper published in the Journal of Drug
- Delivery, Science, and Technology, and even more recently, with antibacterial materials, a paper,
- Exploiting Garlic has been published, now just released, and it's going to appear in the 25th
- anniversary issue of Macromolecular Materials and Engineering. So the actual opportunities
- in core sheath gyration are enormous, and we like to take a lot of students who have the drive and
- enthusiasm to take this forward. We also have Nanang Kosim, who works with Gareth Williams.
- He's been able to combine the core sheath scenario to handle both hydrophilic and hydrophobic drugs.
- So when I wanted people to give me slides for this particular talk, I had a whole flood of
- them. I'm very sorry I can't use all of them because of the timing, but this is the kind
- of front that we are moving in a nutshell. We also have some very interesting work forming
- with Professor Biqiong Chen. Professor Chen is a very talented materials chemist. She knows how to
- put together polymers that are say, for example, self-healing, and thermoplastic polyurethanes,
- they are bio based, but the key question is can you form them into something that can be used,
- form them in maybe larger quantities that can attract the industry scaled up production, and
- the answer is yes. This is only a very preliminary experiment. We are still at the tip of the work,
- progressing downwards. We published our initial ideas in ACS Applied Materials and Interfaces,
- and getting anything through there is like getting a camel through the eye of a needle, but we did
- manage it after a lot of argument and debate, and now we are into the core sheath scenario
- where we hope to have a conducting core and the bio based powder, bio based fibre actually on
- the surface. So this work is actually progressing very well. We also got together to do a special
- issue on the more sustainable aspects of using polymers. We always have to hark back on that,
- because I do think that this is going to be a major, major issue in the eyes of the public. It's
- got to be dealt with at our end as scientists and engineers, not being left to the rejection at that
- end. We also had some very good experiences making filters. This is a consortium that went to EPSRC
- and got funding, and Professor Lena Ciric was the leader of that. Our pressurised gyration work was
- included. So was Dr Guogeng Ren and Hertfordshire University to do the actual biological testing,
- but we were able to produce these actual filters, having that structure where the nanoparticles that
- really drive out or destroy viruses and bacteria can be placed in those filters,
- and this is the work of Dr Rupi Matharu. She came up with many, many compositions of nanoparticles
- containing filters, and I do think this is a project that has a future and will move forward.
- I'm very grateful to Professor John Oxford, who comes from time to time to give advice to us on
- how we should move with this kind of scenario. Now, one important thing is on the gyrator,
- and this is a mechanical engineering scenario, you've got to control the actual aerodynamics
- of formation. If your collection is right, you can make whatever structure of fibre mesh that
- you want. This is the work of Ezra Alton, a senior PhD student when she was a visiting
- scholar, and now she's a UCL scholar doing this work to completion. Bandage forming is a very,
- very important project in the lab, and what more, we have decided to exploit this, maybe in the
- core sheath format, using natural materials. I'm a great believer that you can use natural materials,
- like cinnamon, garlic more liberally than the other synthetic toxic materials and bring this
- to the interest of the public and the industry, and it is happening, because from September 2024,
- a new PhD student funded exclusively by industry will look at cinnamon and how it can be blended
- in to this kind of scenario. So we look forward to that. Alongside this, Mehmet Idogdu, another
- PhD student from Turkey who is also completing has done a lot of work on particles. So the
- particle fibre combination is going together very, very effectively. This is the dream, and
- I'm very grateful to Professor Helge Wudermann, who gave us the kind of green light to try this,
- and Dr Jubair Ahmed tried it. We think the gyrator is good for forming the actual bandage,
- but the smart material can be deposited more effectively by an electrospray. So we want to
- combine the two. We haven't quite been able to get the funding for this work, but I think automating
- the production is something else that the industry is going to look at, and the industry is going to
- want to come to fruition. So that is something that we are working very hard on. Now, this is
- an example of a very enterprising undergraduate project student, Carlota von Thadden, one
- who is now doing her PhD in another university abroad. I gave her the problem of clove bud oil,
- which is also a very good antibacterial agent. She was able to do lots of experiments and came
- up with lots of combinations of composition, and the pressurised gyration variables, and combining
- it with some other work, we were able to publish it in the Journal of Functional Biomaterials, and
- this one is the feature paper and Editor's Choice that has come up. Similarly with casein, something
- that has hit the actual headlines and newspaper headlines are not always to be taken seriously,
- but combining with Professor Muhammad Kam at Marmara University, we were able to show that
- casein just taken out of milk fat could be a very, very effective antimicrobial agent as shown by in
- vivo experiments that were done at their end. We also have never let go, the interest in masks. We
- can't continue to use disposable masks at the rate of, I checked this on the internet, 129 billion
- per month globally. It's a very high penalty. You've got to have more efficient structures and
- MSC project student Ruiran Huang took it up, and I'm very grateful to the Royal Academy, who gave
- funding to generate enthusiasm in me to make masks in different ways, mask containing fibres. We
- think by changing the structure and the face, we will be able to get better masks that can be used
- more efficiently. One other piece of work that really hit the headlines was the work that Hussein
- Alenezi did for his PhD. He showed how the gyrator works, how, using a transparent port, he was able
- to demonstrate how the actual fibres form both analytically and experimentally, and this really
- was taken up big time by the American Institute of Physics, and I think this has a lot more mileage
- to cover. I do think that what we really want to exploit, Ham Tamaj and Professor Tony Harker,
- with myself and lots of other authors are going to look at this, is to use hollow fibres,
- produce hollow fibres using this scenario. The initial results using electron microscopy and CT
- scans are very promising and the idea is to have a hollow fibre, but also to line up the inside
- of that fibre simultaneously by the gyration root, using a lot of single fibres to simulate
- a nerve tissue engineering scenario. My final few slides are on the environment chairperson. We now
- routinely, this is the work of Manul Amarakoon, American PhD student, look at the parameters,
- look at what we generate in terms of energy. That is going on at great pace and Global Challenges
- published a recent paper, and also, I am a big fan of not using the grid. Most of our gyrators now in
- the lab can be used using batteries, and that's the kind of ideology I'm going to. This is also
- actually portable. I thought of bringing that in for a demonstration here, but was warned by health
- and safety experts to be rather careful. It's not dangerous at all in the sense that it is a very
- simple, water soluble polymer composition, but this is where I want to go, as is what is dictated
- by Ayda Afshar's work. She graduated recently and the concept here, not to use single polymers to
- join them up. So we reviewed the literature. We have to think of polymers like metals. Look at the
- phase diagram scenarios, and we only very recently published a paper on this system, which we think
- will lead to others thinking about alloyed systems as well. I want to wind up with three slides,
- and that is the work of Yanqi Deng, a PhD student. She has taken this environmental issue very,
- very seriously, thank you, and she has been out to convert that pressurised gyration root
- into a more efficient process. Same diameter of fibres throughout, whatever the length you want,
- and if you use nozzles instead of the original PG pot, you can get an even higher yield. So this is
- something that we are going to really, really look at in the future. If enough is not enough,
- Yanqi turned the gyrator upside down. This is the kind of thing that gives me nightmares sometimes,
- but of course, we've got to tolerate some kind of excitement. These are all water soluble materials,
- and here, she's developing a route for alginate fibres. We can take them from seaweed. We now
- know by getting them into water, and that's why the gyrator is turned into a horizontal axis,
- we can prepare either films, ribbons or fibres, and we can give you the ranges scientifically.
- The last slide is this one, a very developing collaboration with Napier Edinburgh University.
- They like to use nanocellulose derived from waste materials. We like that idea as well, and
- using the inverted version of pressurised gyration that Yanqi has developed, we've been able to use,
- this is plant derived and this is animal derived into films, ribbons of fibres in a very methodical
- and scientific way. So I think, chairperson, I will stop there. I could go on and on and on,
- but we don't want that. We have to go and enjoy ourselves a little bit as well, I'm told. I never
- produce conclusions at the end of my lectures, particularly to conferences. I don't think
- science ever concludes like that. If you try to conclude it, it'll give you another whole myriad
- of problems coming forward. So I will leave it at that but it's been a great pleasure working
- for UCL, the education powerhouse, with such talented people, that is the actual conclusion,
- to generate all these results. We published the results open access so that the funders
- are also extra happy and people can exploit the results as well. Sometimes you wonder why you wait
- until the evening of life to have all this at the forefront, and it's no surprise that sometimes the
- best wine is drunk at the end, as was in The Great Miracle 2000 years ago, but I certainly hope not
- today when we go out there. So thank you very much indeed, and thank you everyone for listening.
- Well, thank you very much. That was a tour de force lecture with
- a huge amount of fascinating and impressive engineering in there. So I hope you won't
- mind if we open up to the floor for a few…
- You are doing a fine job on your timing.
- So over to you in the audience. I think we do have some helpers with microphones. We'd ask you to
- put your hand up if you would like to ask a question, and one of our helpers with
- microphones will make their way to you. So I'll open to the floor. Any questions?
- They'll all come up to me when we are drinking the wine.
- They will, and they'll ask their questions then. They'll just wait until you're about to take a
- sip. We have a question down in the second row, the gentleman in the suit and the tie there. A
- microphone is making its way to you.
- tour de force. If you have to choose one system where you have a bioactive material which you
- want to concentrate on, and you want to put into one of your advanced structures, what would that
- be? Because what I want to see is where now is this going to go into the clinic and start to
- benefit patients. So your thoughts on where you're taking that forward would be very helpful.
- Well, the answer, the honest answer unfortunately, is that the traditional ones like PLGA,
- if you want biopolymers, and PCL, always will require some amount of harsh solvent to process,
- but that doesn't mean to say, and this is four slides back that I produced, that you can't mix
- it up with a binary system. PEO is a water soluble polymer that is, for all intents and purposes,
- harmless. So I have two strategies. One, to use binary polymers to try and minimise the use of the
- actual biopolymer that requires harsh conditions, and also like Yanqi has done in the last few
- slides, there are very exciting biomaterials that are still to be uncovered, in a natural sense,
- and I think we should go after these. Not necessarily alginates, but maybe nanocellulose
- types. They have a lot of biological uses that Edinburgh Napier can produce, and we can use those
- very effectively in biological structures. Now, I know it's difficult and a very good example is the
- use of masks. One of the things that I asked Professor John Oxford when I met him with Dr
- Wren about four weeks ago. 'What do you want?' He said, prepare a mask that will remain for 20 years
- and will be very active, using natural materials. That is something that's difficult because natural
- materials are created to degrade quickly, but you know, I never say never. I operate like a
- 00. I never say never. I think there's a lot of things to be uncovered and I think that's where
- the future is. A lot of materials has to come to the fore coupled with engineering, of course.
- I think further back, we have a gentleman with his hand up, three rows behind there.
- I'm a non-specialist, but still I was curious as to how well or how poorly the physics of the
- processes that your fabrication involves are understood. Presumably it would have
- some non-Newtonian flow, some viscosity affects, surface tension, et cetera.
- Now you raise a very important point. You're asking how the surface, if I understood right,
- can be modified. That is very important because if the surface is porous,
- as I've shown with the collaborative work with Professor Roy at Sheffield, we can get one set
- of cellular interactions, but if it's not porous, we can get another set. So it's a question of the
- biologists telling us, this is what we want, and we will tailor the manufacturing to suit
- that particular process. I can tell you to get porosity on the surface, you have to use, probably
- in core sheath gyration, a more volatile solvent. Now, that contradicts my point that I finished off
- with saying that we should try and minimise volatile, dangerous solvents. So once again,
- science doesn't allow you to win completely, a lot more work has to be done but intelligently done.
- That's the best answer I could give you.
- if anyone is harbouring a question they want to ask. Handily placed for our microphone.
- Thank you for the excellent presentation you gave. I think my question is going to be EHD related.
- You have worked on graphene on the surface of your fibres. Now it can attract all the
- biological molecules, like virus and bacteria and so on, and now there is a need for inactivating
- the virus or bacteria. Have you thought about it? If so, how would you do it?
- We have in collaboration with Dr Tabeesh who's got a lot of expertise, we can prepare that kind of
- structure, but my concern about graphene is that I don't know enough about graphene or graphene
- oxide as to how they can be detached from the surface and come loose. So until that particular
- problem is solved, and we are in the process of trying to solve that, I don't think we'll
- get the complete answer for graphene or graphene oxide. It's a carbon form, and carbon is not the
- preferred material in biological expeditions, let alone anything else. So I do think I reserve my
- judgement on graphene in that sense, but it has very, very strong properties, particularly at the
- higher loading level that people will definitely try and exploit. So this is the difference. I
- don't want to do something on a laboratory scale and you say, right, I have got the Holy Grail,
- because you've got to expand it to the real scale then. It's like making a can of soup, really. I
- mean, the kind of example Professor Evans would give me, if I talked about mixture quality. When
- you have quarter of a can, you get a very good mixture quality, but of course, when you expand
- that to a very big can, and if you pick up a sample, you don't get that kind of answer. So it's
- a mixture quality problem as well. Thank you.
- the excellent answers. Again, I feel there is so much more. It's a very rich talk and
- a rich stream of science. We have one last thing to do before we close this part of
- the proceedings and that is the pleasure that I have to formally say that the Clifford Paterson
- Medal and Lecture 2024 is awarded to Professor Mohan Edirisinghe for his seminal research in
- engineering science of making small structures from soft matter in novel, scalable ways,
- creating new frontiers in functional applications, causing major advances in manufacturing and
- healthcare. It's a great pleasure to have the ability to hand over to you the medal and your
- scroll. I think the photographer probably is going to want to take our picture.
- Thank you very much.
- and congratulations.
Join us for the Clifford Paterson Prize Lecture 2024 given by Professor Mohan Edirisinghe.
Inventing scalable and sustainable methods for making bubbles/vesicles, particles/capsules and fibres of the micro-nano scale, boosting public healthcare is an essential part of modern manufacturing engineering sciences. Microbubbles are very effective drug delivery agents and are also crucial contrast agents in ultrasound imaging. Particles and capsules are extensively used in modern therapeutic delivery. Fibres, in the form of scaffolds, filters, patches and dressings can be used in many aspects of healthcare; advanced tissue engineering, microbial screening, drug delivery and chronic wound healing bandage strategies. The quest to make these structures reproducibly with high productivity in a sustainable manner is elusive and is a very buoyant research topic as scale-up possibilities and actual sustainable industrial manufacturing in addition to new scientific, engineering and technological innovations are crucial factors. The EdirisingheLab@UCL, is at the forefront of this research internationally and this lecture will elucidate how these novel sustainable making developments are taking place at great pace. For example, in the past two decades we have innovated new methods for making this new generation of biomaterials which enables healthcare, and in the last decade our research into pressure spinning incorporating sustainable materials, environmentally friendly solvents and energy efficiency has elevated fibre manufacturing to new levels.
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