Cell recognition chromatography based on size-matched particle imprints for removal of leukemic from healthy white blood cells
17 January 2020
A team led by Prof Paunov reported a cell recognition chromatography approach for blood cancer cell separation from healthy peripheral blood mononuclear cells (PBMCs) based on size-matched functionalized particle imprints. The study was just published in ACS Applied Bio Materials. We made negative imprints from layers of 15 μm polymeric microbeads closely matching the size of human leukemic cells (HL60). We replicated these imprints on a large scale with UV curable polyurethane resin using nanoimprinting lithography. The imprints were surface functionalized to promote a weak attraction toward cells. When a matching cell fits into an imprint cavity, its contact area with the imprint is maximized, which amplifies the attraction and the binding selectivity.
We tested these imprints specificity for depleting myeloblasts from a mixture with healthy human PBMCs in a cell recognition chromatography setup hosting the imprint. Particle imprint based cell recognition chromatography was able to achieve selective myeloblast depletion from initial 11.7% HL60 (88.3% PBMC) to less than 1.3% HL60 after 3 hours of circulation. The cell recognition chromatography with size-matched microbead imprints can be employed as an efficient cell separation technique and potentially lead to alternative therapies for myeloblasts removal from peripheral blood of patients with acute myeloid leukemia.
Read more about this in our paper: Chester, R., Das, A.A.K., Medlock, J., Nees, D., Allsup, D.J., Madden, L.A., Paunov, V.N., Removal of Human Leukemic Cells from Peripheral Blood Mononuclear Cells by Cell Recognition Chromatography with Size Matched Particle Imprints, ACS Appl. Bio Mater.,3 (2020) 789-800.
Surface-Modified Zinc Oxide Nanoparticles for Antialgal and Antiyeast Applications
10 January 2020
We examined the activity of various concentrations of bare and surface modified ZnONPs toward microalgae (C. reinhardtii) and yeast (S. cerevisiae) cells upon illumination with UV light compared with that under visible light and in dark conditions to evaluate the impact of the oxidative stress due to the reactive oxygen species (ROS). We also prepared ZnS-coated ZnONPs, SiO2-coated ZnONPs, and combinations of polyelectrolyte (PSS and PAH)-coated ZnONPs and examined their antiyeast and antialgal effects. The nanoparticles of the anionic surface (ZnONPs/ZnS, ZnONPs/SiO2, and ZnONPs/PSS) showed much lower antialgal and antiyeast activity than the ones with a cationic surface functionality (ZnONPs/PSS/PAH and bare ZnONPs).
The effect of the ZnONPs surface coating was found to be much stronger than the ROS effect due to illumination with UV light. Our results indicate that the nanoparticles attachment to the microbial cell wall is much more important for their antimicrobial action than the ROS generation alone. This could be explained by the poor adhesion of ZnONPs/ZnS, ZnONPs/SiO2, and ZnONPs/PSS to the cells due to electrostatic repulsion. In contrast, the particle–cell electrostatic adhesion in the case of cationic ZnONPs/PSS/PAH and bare ZnONPs led to enhanced antiyeast and antialgal action. The study was done as a part of the PhD thesis of Ahmed Halbus under the supervision of prof Paunov.
Read more about this in our ASAP paper: Halbus, A.F., Horozov, T.S., Paunov, V.N., Surface-Modified Zinc Oxide Nanoparticles for Antialgal and Antiyeast Applications, ACS Appl. Nanomater., 3 (2019) 440-451.
Prof Paunov delivered two invited research lectures at KAUST
18-19 November 2019
Prof Paunov was invited to give two research seminars during his visit at King Abdullah University of Science and Technology (KAUST) at Thuwal, SA. KAUST is a very young institution (founded in 2009) but already ranks in the top ten of Nature Young Universities Index (1st in the Middle East and 6th in the World).
On the 18th of November 2019 Prof Paunov addressed the Physical Sciences & Engineering Division of KAUST with his invited lecture “Fabrication of Hierarchically Structured and Porous Composites by Using Gel Templating, Viscous Trapping and Capillary Suspensions“. On the 19th of November 2019 he gave an invited research seminar to the Biological & Environmental Science and Engineering division of KAUST about “Nanotechnologies in the Fight Against Antimicrobial Resistance“.
Paunov group developed a super-efficient way of clearing wound-related bacterial biofilms
13 November 2019
From now on there will be no place to hide for biofilm forming bacteria. Paunov Research Group developed a novel nanotechnology to clear biofilms based on protease-functionalized nanogel carriers loaded with antibiotics. Such active antibiotic nanocarriers, surface coated with a special type of protease (Alcalase), “digest” their way through the biofilm extracellular polymer matrix, reach the buried bacteria, and deliver a high dose of antibiotic directly on their cell walls, which overwhelms their defenses. We demonstrated the effectivness of the Alcalase-functionalized nanocarriers against six wound biofilm-forming bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Klebsiella pneumoniae, Escherichia coli, and Enterococcus faecalis.
We confirmed a 6-fold decrease in the biofilm mass and a substantial reduction in the bacterial cell density. We also showed that co-treatments of ciprofloxacin and Alcalase-coated Carbopol nanogels led to a 3-log reduction in viable biofilm-forming cells when compared to ciprofloxacin treatments alone. Encapsulating an equivalent concentration of ciprofloxacin into the Alcalase-coated nanogel particles boosted their antibacterial effect much further, reducing the bacterial cell viability to below detectable amounts. This ground breaking nanotechnology has the potential to become a very powerful treatment of chronically infected wounds with biofilm-forming bacteria. The work was done our PhD student Paul Weldrick, supervised by Prof Paunov and funded by the University of Hull Advanced Wound Care PhD cluster program.
Read more about this in our ASAP paper: Weldrick, P.J., Hardman, M.J., Paunov, V.N., Enhanced Clearing of Wound-Related Pathogenic Bacterial Biofilms Using Protease-Functionalized Antibiotic Nanocarriers, ACS Appl. Mater. Interf., 11 (2019) 43902-43919.
‘Ghost’ silica nanoparticles of ‘host’-inherited antimicrobial action
14 October 2019
Our research group has designed surface-rough mesoporous silica
nanoparticles (‘ghost’ SiO2NPs) by using composite mesoporous copper oxide nanoparticles as templates (‘host’ CuONPs), which allowed us to mimic their surface morphology. We functionalized them with (3-glycidyloxypropyl)trimethoxysilane (GLYMO) to permit additional covalent coupling of 4-hydroxyphenylboronic acid (4-HPBA). The cis-diol groups from sugars expressed on the bacterial cell wall can form reversible boronic ester bonds with the boronic acid groups on the ‘ghost’ SiO2NPs/GLYMO/HPBA surface and bind covalently to the bacteria, resulting in a very strong amplification of their antibacterial activity. We show that the rough surface morphology of the ‘ghost’ SiO2NPs, which upon covalent bonding between the rough SiO2NPs/GLYMO/HPBA and the bacterial cell membrane causes its impaling on the surface-rough features and produces membrane dislocation that kills the bacteria. The results indicate that the combination of rough surface morphology and strong adhesion of the particle surface to the bacteria can make even benign material such as silica act as a strong antimicrobial agent.
Read more about this in our paper: Halbus, A.F., Horozov, T.S., Paunov, V.N., ACS Appl. Mater. Interf., 11 (2019) 38519−38530. DOI:10.1021/acsami.9b14403.
Welcome to AnHeng Wang
17 September 2019
Paunov Research Group was joined by a new PhD student, Mr AnHeng Wang. He is coming to our group from Shenyang Normal University and is funded by the Chinese Scholarship Council.
AnHeng will be involved in a new project of forming hepatocyte clusteroids and developing new ways for 3D cell culturing and tissue engineering of liver tissue for applications in regenerative medicine. He will be working under the supervision of Prof Paunov and Dr Madden (Biomedical Sciences). We wish him a great start and successful completion of his PhD studies in our group.
Osama Alswafy successfully passed his PhD viva
3 September 2019
Congratulations to Osama Alswafy who defended successfully his PhD thesis. We present here a photo of the happy PhD candidate after the viva. Osama has been a valuable member of Paunov Research Group for over 4 years. His PhD thesis was entitled “NOVEL APPLICATIONS OF MICRO-ENCAPSULATED OPTICAL BRIGHTENERS”. Osama was jointly supervised by Prof Paunov and Prof Greenway. Here are also some photos of Osama Alswafy with his supervisor, Pof Paunov, and his internal examiner Prof Nicole Pamme (Hull) and external examiner, Prof Brent Murray (Leeds), as well as with his friends and colleagues from the Department of Chemistry. We wish him all the best in his future career!
Ahmed Halbus (Al-Mamoori) successfully passed his PhD viva
29 July 2019
Congratulations to Ahmed Al-Mamoori (Halbus) who defended successfully his PhD thesis. Here is a photo of the happy PhD candidate after the viva. Ahmed has been a member of Prof Paunov’s research group for more than 4 years. His PhD thesis was entitled “NOVEL NANOPARTICLE FORMULATIONS FOR ANTIMICROBIAL APPLICATIONS”. Ahmed was jointly supervised by Prof Paunov and Dr Horozov. He developed a range of surface functionalised inorganic particles from magnesium hydroxide, copper oxide, zinc oxide and characterized their antimicrobial activity against microalgae, yeast and various bacteria. One of his major achievements was the development of non-electrostatic mechanism of attachment of functionalised nanoparticles to bacterial cells which relies on self-grafting by formation of boronic ester with carbohydrates expressed on the cell surface. Dr Halbus will be heading back to the University of Babylon where he holds a lectureship position. We wish him all the best in his future career!
Novel way of skin grafts preparation using prefabricated clusters of human keratinocytes
11 July 2019
Professor Paunov’s team engineered a new ways of preparation of skin grafts using prefabricated clusters of human keratinocytes. We report novel, inexpensive and scalable methodology to produce large quantities of human keratinocyte cell spheroids and use them to formulate model skin grafts.The work was done in 2018 by a large team, including French placement students from ESCOM (Sebatien Dominici) and REIMS (Sevde Celik) advised by Prof Paunov, Dr Madden (Biomed Science) and Ben Filby. This is a follow up of Ben’s MChem Thesis where this method for cell spheroids preparation was first developed by using water-in-water Pickering emulsions as templates.
Read more about this work in the newly published paper: Celik, S.B.G.; Dominici, S.R.; Filby, B.W.; Das, A.A.K.; Madden, L.A.; Paunov, V.N. Fabrication of Human Keratinocyte Cell Clusters for Skin Graft Applications by Templating Water-in-Water Pickering Emulsions. Biomimetics 2019, 4, 50.
Prof Paunov led research team attacks antimicrobial resistance
21 May 2019
Antimicrobial resistance is a growing clinical epidemic. Our research team led by Prof Paunov and funded by University of Hull Advanced Wound Care PhD cluster has just published a landmark paper in the RSC journal Nanoscale, where we demonstrate that nanogel carriers for tetracycline and lincomycin coated with a bio-compatible cationic polyelectrolyte (bPEI) can overcome the antibiotic resistance against a range of clinically isolated bacterial pathogens. The work was done by our PhD student Paul Weldrick supervised by Prof Paunov in collaboration with Prof Hardman group at Hull York Medical School.
Our experiments revealed that bPEI-coated nanogels with encapsulated tetracycline or lincomycin, developed and formulated in Paunov Research Group, displayed increased antimicrobial performance against selected wound-derived bacteria, including strains highly resistant to the free antibiotic in solution. Additionally, our nanocarrier-based antibiotics showed no detectable cytotoxic effect against human skin cells (keratinocytes). We attribute the increase in antimicrobial activity of the cationically-functionalised antibiotic-loaded nanogel carriers to specific electrostatic adhesion to the microbial cell wall delivering a higher local antibiotic concentration. Such nanotechnology based approach may enhance the effectiveness of a wide variety of existing antibiotics, offering a potentially new mechanism to overcome antibiotic resistance.
Read the paper: Paul Weldrick et al., Nanoscale, 2019, 11, 10472-10485. Breathing new life into old antibiotics: overcoming antibacterial resistance by antibiotic-loaded nanogel carriers with cationic surface functionality
ESCOM university student Timoté Costa arrives at Paunov Research Group for a summer placement
20 May 2019
Our research group was joined by a placement student Timoté Costa from ESCOM, France. ESCOM is a French grande école for chemical engineering located in Compiègne, France.
Timoté Costa will be working with us at the University of Hull for 4.5 months on novel ways to target circulating tumour cells with a bioimprinting technology under the supervision of Prof Paunov (Chemistry) and Dr Leigh Madden (Biomedical Sciences). We welcome Timoté as a part of our research team as wish him success in his project.
Prof Paunov research team targets blood cancer with a bioimprinting technology
7 May 2019
Our research group has just published a communication on a new method for depletion of peripheral blood from leukemic cells by using cell shape recognition mediated by bioimpring-cell interactions. The paper was published in the RSC Journal of Materials Chemistry B. We report a large scale preparation of bioimprints of layers of cultured leukemic HL60 cells which can perform cell shape and size recognition from a mixture with peripheral blood mononuclear cells (PBMCs).
We demonstrate that the bioimprint-cell attraction combined with surface modification and flow rate control allows depletion of the HL60 cells from peripheral blood which can be used for development of alternative therapies of acute myeloid leukaemia (AML). We engineered the surface of the bioimprint to have a weak attraction with the cells, which is strongly amplified when there is a shape and size match between the individual cells and the imprinted surface. Due to inherent size and morphology differences between myeloblasts and normal blood cells, this resulted in much higher retention of the former on the bioimprint. The work was funded by CRUK Pioneer award with Prof Paunov as a PI and Dr Madden and Dr Allsup as Co-PIs.
Read the paper: Das, A.A.K., Medlock, J., Liang, H., Nees, D., Allsup, D.J., Madden, L.A., Paunov, V.N., Bioimprint aided cell recognition and depletion of human leukemic HL60 cells from peripheral blood, J. Mater. Chem. B, 7 (2019) 3497 – 3504.
ESCOM university student Sarra Remmache joined Paunov Research Group for a summer placement
1 May 2019
Our research group was joined by a placement student Sarra Remmache from ÉCOLE SUPÉRIEURE DE CHIMIE ORGANIQUE ET MINÉRALE (ESCOM). ESCOM is a French grande école for chemical engineering located in Compiègne, France.
Sarra will be working with us for 6 months in our labs on a smart materials based on capillary suspensions under the supervision of Prof Paunov (Chemistry). We welcome Sarra as a part of our research team as wish her success in her projects.
Dual functionalised nanocarrers boost the antimicrobial action of vancomycin
15 April 2019
We have just published an article in the Journal of Materials Chemistry B , demonstrating a strong enhancement of the antimicrobial action of vancomycin (VCM) encapsulated in dual-surface functionalised shellac nanocarriers. These shellac nanocarriers for VCM were produced in two steps: (i) a pH drop from aqueous ammonium shellac solution containing Poloxamer 407 (P407) as a steric stabilising polymer in solution of vancomycin hydrochloride, and (ii) subsequent doping with the insoluble cationic surfactant octadecylthrimethylammonium bromide (ODTAB) though a solvent change to yield a cationic surface functionality.
The enhanced VCM action is explained with the increased electrostatic adhesion between the ODTAB-coated VCM-loaded shellac NPs and the negatively charged surface of the microbial cell walls which allows local delivery of VCM with a high concentration directly on the cell membrane. This nanocarrier-mediated boost of the antibiotic action may potentially breathe new life into old antibiotics and help to fight off antibiotic resistance by making them more effective. This research was a part of Saba Al-Obaidy PhD thesis supervised by Prof Paunov and Prof Greenway.
Read the article: Al-Obaidy, S.S.M., Halbus, A.F., Greenway, G.M., Paunov, V.N., Boosting the antimicrobial action of vancomycin formulated in shellac nanoparticles of dual-surface functionality, J. Mater. Chem. B, 7 (2019) 3119-3133.
Le Mans University student Melvin Normand joined Paunov Research Group for a summer placement
15 April 2019
Paunov research group was joined by a placement student Melvin Normand from Le Mans University. University of Le Mans (Le Mans Université) is a French university, based in Le Mans, under the Academy of Nantes, France.
Melvin will be working over the summer in our labs on a novel method for preparation of cell spheroids for tissue engineering applications under the supervision of Prof Paunov (Chemistry) and Dr Madden (Biomedical Sciences). We welcome Melvin as a part of our research team this summer as wish him success in his projects.
Self-grafting copper oxide nanoparticles with ultra-enhanced antibacterial action
20 March 2019
Our group just published an article in the ACS Applied Materials and Interfaces where we developed and tested a novel type of formulation for copper oxide (CuONPs) which have been functionalized with (3-glycidyloxypropyl)trimethoxysilane (GLYMO) to allow further covalent coupling of 4-hydroxyphenylboronic acid (4-HPBA). As the boronic acid (BA) groups on the surface of CuONPs/GLYMO/4-HPBA can form reversible covalent bonds with the diol groups of glycoproteins on the bacterial cell surface, they can strongly bind to the cells walls resulting in a very strong enhancement of their antibacterial action which is not based on electrostatic adhesion.
The self-grafting effect makes the functionalized CuONPs/GLYMO/4-HPBA much more effective antimicrobials than the bare CuONPs. We found that our particles CuONPs/GLYMO/4-HPBA do not affect the viability of human skin cells at concentrations which they are deadly for a range of bacteria. The work was done in our labs by our PhD student Ahmed Halbus (Al-Mamoori) supervised by Prof Paunov and co-supervised by Dr Horozov.
Read the article: Halbus, A.F., Horozov, T.S., Paunov, V.N., Strongly enhanced antibacterial action of copper oxide nanoparticles with boronic acid surface functionality, ACS Appl. Mater. Interf., 11 (2019) 12232–12243.
Dr Bongkot Ngamsom joined Paunov Research Group as a post-doctoral fellow
1 February 2019
Our group was joined by Dr Bongkot Ngamsom as a post-doc who will be working on an industrially funded project. She will be involved in the development of novel formulations for delivery of bioactives. We welcome her in our research team and wish her a successful start of the project.
ESCOM students Margot Chaudy and Nicolas Courtignon joined Paunov research group for a summer placement
1 February 2019
Paunov research group has just received two placement students from ÉCOLE SUPÉRIEURE DE CHIMIE ORGANIQUE ET MINÉRALE (ESCOM). ESCOM is a French grande école for chemical engineering located in Compiègne, France.
Margot Chaudy will be working on a novel method for extraction of nitrogen oxides from polluted air under the supervision of Prof Paunov. Nicolas Courtignon will work on a project targeting blood cancers using bioimprints under the supervision of Dr Madden and Prof Paunov. We welcome Margot and Nicolas as a part of our research team this summer as wish them success in their projects.
New way to reduce calories in bakery products
9 January 2019
Prof Paunov and Dr Horozov have just published a new editorial in the magazine BAKINGEUROPE which elaborates on use of one of their new inventions – a highly melt resistant food-grade hydrogel in the development of less caloric bakery products.
The idea is to use a slurry of melt-resistant hydrogel beads mixed with batter to produce pancakes with up to 25% less calories, as an example of the application of this method. The method can potentially be applied to many other bakery products, like muffins, confectioneries, biscuits, bread and even pizza. For more details, please see the section Cutting Edge in the magazine Winter 2018 edition:
Baking Europe is a very popular magazine which is read in over 40 countries across the world.
Jevan Medlock successfully passed his PhD viva
28 November 2018
Congratulations to Jevan Medlock who defended successfully his PhD thesis. Here is a photo of the happy PhD candidate after the viva.
Jevan has been a member of Prof Paunov’s research group for more than 4 years. His PhD thesis was entitled “BIOIMPRINTING TECHNOLOGIES FOR REMOVAL OF MYELOBLASTS FROM PERIPHERAL BLOOD”. Jevan was jointly supervised by Prof Paunov and Dr Leigh Madden.
He did a multidisciplinary and dynamic project aimed to capture size and shape information from blood cancer cells into polymeric imprints. Bioimprints yield cavities will a complementary morphology to template cells allowing selective rebinding. Dr Jevan Medlock is currently working as a research associate at the Birmingham Woman’s and Children’s NHS Foundation Trust. We wish him all the best in his future career!
Professor Paunov was awarded the Fellowship of the Royal Society of Chemistry
1 June 2018
Professor Paunov has just been granted the status of a Fellow of the Royal Society of Chemistry (FRSC).
Achieving Fellow status in the chemical profession denotes to the wider community a high level of accomplishment as a professional chemist.
Fellows of the Royal Society of Chemistry (UK) are recognized for their outstanding contribution to the advancement of the chemical sciences and to the advancement of the chemical sciences as a profession. Prof Paunov has published extensively in the RSC journals and has build strong international recognition for his interdisciplinary work in materials science, colloids and bio-interfaces.
ESCOM students Sebastien Dominici and Patricia Sinnappu joined Paunov research group for a summer placement
21 May 2018
Paunov research group has just received two placement students from ÉCOLE SUPÉRIEURE DE CHIMIE ORGANIQUE ET MINÉRALE (ESCOM). ESCOM is a French grande école for chemical engineering located in Compiègne, France.
Sebastien Dominici will be working on a tissue engineering project on preparation of model skin grafts under the supervision of Prof Paunov and Dr Madden. Patricia Sinnappu will work on novel type of formulations of functionalised nanoparticles for anti-fungal applications. We welcome Sebastien and Patricia as a part of our research team this summer as wish them success in their projects.
ENSRC students Anna Folberth, Perrine Remaud, Laurine Raimond and Marie Pelle joined our research group for a summer placement
30 April 2018
Paunov research group received four placement students from Ecole Nationale Superieure de Chimie de Rennes (E.N.S.C.R.), a leading Chemical Engineering School in Rennes, France.
They all arrived at the University of Hull at the end of April 2018 to undertake 4 months research projects in our interdisciplinary group at the School of Mathematics and Physical Sciences as a part of her Masters degree in Chemistry and Engineering. Anna Folberth will be studying the bio-luminescence from bacteria and fungal organisms. Laurine Raimond will be involved in a project on developing formulations of antimicrobial nanocarriers in collaboration with Dr Horozov. Perrine Remaud and Marie Pelle will be involved in projects on bioimprinting of blood cancer and pancreatic cancer in collaboration with Dr Leigh Madden at the School of Life Sciences. We wish them all a successful start.
Congratulations to Saba Al-Obaidy for successfully passing her PhD viva
21 March 2018
Congratulations to Saba Al-Obaidy who successfully passed her PhD viva on 21 March 2018 with recommendations for only minor corrections. Saba has been a member of Prof Paunov’s research group for more than 4 years. Her PhD thesis was entitled “Nanocarrier-formulated antimicrobials and microfluidics-based screening assays”. Saba was jointly supervised by Prof Paunov and Prof Greenway.
During her PhD in our research group, Saba worked on novel antimicrobial nanoparticles and showed that they amplify the effect of a variety of antimicrobials. She also demonstrated the role of the different parts of the nanocarrier on the overall antimicrobial efficiency. Saba’s PhD studies ware funded by a scholarship provided by the Ministry of Higher Education of the Republic of Iraq. We celebrated her success with a small party in our School with all supervisors and examiners present, along with Saba’s friends and family. Dr Saba Al-Obaidy will soon be moving back to the University of Babylon to continue her carrier as an academic. On behalf of all members of Paunov’s research group we wish her all the best in her career !
Sevde Celik joined our research group as a placement student from URCA
1 February 2018
We welcome Sevde Celik, who joined our research group at the School of Mathematics and Physical Sciences at the University of Hull for a research placement. Sevde is currently a 5th year undergraduate student from URCA (Université de Reims Champagne-Ardenne, France), where she is studying for a Master Biologie-Santé-Qualité (Biology-Health-Quality). URCA is a French university, in the Academy of Reims, France. Sevde started her 6 months research project in our group as a part of her URSA Masters degree course. Her study is funded by CROUS de Reims scholarship. She will be developing artificial skin grafts by using cell spheroids under the supervision of Prof Paunov (Chemistry) and Dr Madden (Life Sciences).
16 January 2018
Our research group just published a new article on advanced soaps in Materials Chemistry Frontiers, 2018, ASAP article, DOI: 10.1039/c7qm00556c. The study was funded by EPSRC and Unilever. We designed novel soap-hydrogel bead composites which can release actives when pressed. The reduced cost of the smaller amount of soap base required for these materials combined with the possibility to encapsulate actives in the hydrogel beads content and the control of their release would make these composites appealing in personal care products. We envisage that these ‘‘smart’’ soap–hydrogel beads composites could also find application for more sustainable solution within the hotel industry, where millions of partially used soap bars are discarded on a daily basis.
Read more on the journal web-site.
Capillary suspensions of CaCO3 particles in a polar liquid media
14 December 2017
We have just landed another paper on capillary suspensions of calcium carbonate particles in polar media (water or glycerol) by using in-situ particle hydrophobization through the secondary oil phase (see Dunstan et al., Langmuir, 34 (2018) 442−452.).
Capillary suspensions formulated by this method have very different rheology and structuring compared with the ones with uniformly pre-hydrophobized particles. We studied the effects of the particle size and concentration on the viscosity of the capillary suspensions obtained this way. We also determined the minimal particle and secondary liquid phase concentration which yield capillary suspensions for different particle sizes. We did this for both water-based and glycerol based capillary suspensions and three different oils as secondary liquid phase and discussed the results in terms of the particle contact angle and the o/w tension. Read more on the journal web-site.
Thermally responsive capillary suspensions
6 December 2017
We have just published a land mark article on thermally responsive capillary suspensions (see Das et al., ACS Applied Materials and Interfaces, 9 (2017) 44152–44160). Our idea is based on using oil-based suspensions of solid particles with a secondary liquid phase of a solution of a hydrogel-forming polymer. The gelling behavior of the hydrogel-forming polymer in the aqueous phase bridging the solid particles controls the rheology of the whole capillary suspension. We demonstrate capillary suspensions with completely opposite responses to temperature based on agar and methyl cellulose.
Read more on our web-site.
Congratulations to Ben Thompson for successfully passing his PhD viva
1 December 2017
Congratulations to Ben Thompson who successfully passed his PhD viva on 1 December 2017 with recommendations for only minor corrections.
What a difference 2 hours can make! We will leave it to you to guess which photo of him was taken before and which one after the PhD viva.
Ben has been a member of Prof Paunov’s research group for more than 4 years. His PhD thesis was entitled “HIERARCHICALLY STRUCTURED COMPOSITES AND POROUS MATERIALS”. Ben was jointly supervised by Prof Paunov and Dr Horozov.
During his PhD studies, Ben developed novel ultra melt-resistant hydrogels and showed that they can have a variety of applications for fabrication of innovative hierarchically composite materials. He also worked on hydrogel templating and viscous trapping techniques for making similar hierarchically porous materials and demonstrated the applications of these technologies in foods, home and personal care products, as well as some building materials. Ben’s PhD was funded by the an Industrial CASE award from EPSRC and Unilever R&D Vlaardingen.
Dr Benjamin Thompson will soon be moving to the University of Maryland to do a post-doc in the Dept. of Chemical & Biomolecular Engineering under the supervision of Prof. Srinivasa Raghavan. We wish him all the best in his future career!
High throughput method for fabrication of tissue spheroids
23 October 2017
We have just published a simple and generic technique for high throughput generation of tissue spheroids (see Materials Horizons, 4 (2017) 1196-1200). Our idea is based on encapsulation of dispersed adherent cells in a water-in-water emulsion stabilised by protein particles. Emulsion is formed from a cell suspension in an aqueous solution of dextran (DEX), which is dispersed in an aqueous solution of polyethylene oxide (PEO) containing protein particles. The cells are trapped in the DEX drops of a stable DEX/PEO emulsion which they prefer compared with the continuous PEO phase. Further adding of more concentrated PEO phase shrinks the DEX drops and compresses the adherent cells into tissue spheroids which are isolated by breaking the emulsion by dilution with a culture media. We envisage the application of this cheap and scalable technique for rapid preparation of similarly sized spheroids of adherent cells for bioinks for 3D organ bioprinting applications and potentially for tumour models.
Read the paper on the web-site of the RSC journal Materials Horizons.
Paul Weldrick joins Paunov Research Group as a PhD student
5 October 2017
We welcome our new group member Paul Weldrick who joined Paunov Research Group at the University of Hull in October 2017. Paul has received a Biology degree in 2017 from the University of Hull.
Paul Weldrick PhD project involves “Nanocarrier-mediated delivery of antimicrobials to chronic wounds” .
This PhD project is a part of a cluster of 7 fully-funded University of Hull studentships: “Advanced Wound Care: From Novel Therapies to Clinical Trials”. Paul will be co-supervised by Prof Paunov (Chemistry) with his main supervisor being Dr Matthew Hardman (Life Sciences).
Benjamin Filby joins Paunov Research Group for a PhD study
27 September 2017
Warm welcome to our new PhD student Ben Filby who joined Paunov Research Group at the University of Hull in September 2017. Ben received his MChem degree in Chemistry in 2017 from the Department of Chemistry of the University of Hull.
Ben Filby’s PhD project involves “Monitoring & manipulating wound microbiota via cell shape recognition“.
His PhD project is a part of a cluster of 7 fully-funded University of Hull studentships: “Advanced Wound Care: From Novel Therapies to Clinical Trials”. Ben will be supervised by Prof Paunov (Chemistry) with co-supervisors, Prof Pamme (Chemistry) and Dr Hardman (Biology).
New way to enhance the antimicrobial action of berberine
26 September 2017
We have just published a new paper in J. Materials Chemistry B where we report a novel surface functionalised nanocarrier for berberine by using polyacrylic acid based nanogel particles (Carbopol Aqua SF1) coated with a cationic polyelectrolyte (PDAC) which shows a strong boost in the berberine antimicrobial action. The latter was studied on C. reinhardtii microalgae and E. coli for the berberine-loaded nanogel (BLC) coated with a cationic polyelectrolyte (PDAC-coated BLC).
We demonstrated that the cationic coating of the nanogel strongly increased the antimicrobial action of berberine against both C. reinhardtii and E. coli even for very short incubation times. The increase in the antimicrobial activity was attributed to the favourable electrostatic adhesion between the cationic PDAC-coated BLC and the anionic cell membranes allowing the accumulation of BLC particles on the cell walls and the local release of concentrated berberine causing the cell death. This nanotechnology-inspired approach can be potentially applied to boost the antimicrobial action for a range of low-molecular weight antimicrobial and antialgal agents by using cationic surface-functionalised nanogel carriers. A similar strategy could also find applications for enhancing the action of topical antibiotics and antifungal agents and may be used to bypass antimicrobial resistance.
Read the paper on the web-site of the RSC journal J. Mater. Chem B.
We created ultra melt-resistant hydrogels from food grade carbohydrates
25 September 2017
Paunov’s Research Group has just published a paper in RSC Advances where we report a binary hydrogel system made from two food grade biopolymers, agar and methylcellulose (Agar-MC) which does not require addition of salt for gelation to occur and has very unusual rheological and thermal properties. We found that the storage modulus of the Agar-MC hydrogel far exceeds those of hydrogels from the individual components. Above the melting point of agar, the storage modulus of Agar-MC hydrogel decreases but is still an elastic hydrogel with mechanical properties dominated by the MC gelation. By varying the mixing ratio of the two polymers, agar and MC, it was possible to engineer a food grade hydrogel of controlled mechanical properties and thermal response. The produced highly thermally stable hydrogel shows melt resistance which may find application in high temperature food processing and materials templating.
Read more on this topic on our web-site.
Paunov’s CRUK Pioneer project team published a key review: Cancer bioimprinting and cell shape recognition for diagnosis and targeted treatment
29 June 2017
Prof Paunov’s CRUK Pioneer Award project team has just published a key review article in the RSC journal Chemical Society Reviews. Congrats to Jevan Medlock, Dr Anupam Das, Dr Leigh Madden and Dr David Allsup who contributed to this work.
Jevan Medlock, Anupam A.K. Das, Leigh A. Madden, David J. Allsup and Vesselin N. Paunov, Cancer bioimprinting and cell shape recognition for diagnosis and targeted treatment. Chemical Society Reviews, 2017, 46, 5110-5127.
The review focuses on the possible applications of bioimprinting with particular regards to cancer understanding, diagnosis and therapy. Surface imprinting allows the capture of increasingly complex motifs from polypeptides to single cell organisms and mammalian cells. Highly specific cell shape recognition can also be achieved by cell interaction with imprints that can be made into polymer matrices to mimic biological systems at a molecular level. Bioimprinting has also been used to achieve nanometre-scale resolution imaging of cancer cells. Studies of bioimprint-based drug delivery on cancer cells have been recently trialed in vitro and show that this approach can potentially improve existing chemotherapeutic approaches. Cell imprints, incorporated into biosensors can allow the limits of detection to be improved or negate the need for extensive patient sample processing. Similar cell imprinting platforms can be used for nanoscale imaging of cancer morphology, as well as to investigate topographical signalling of cancer cells in vitro.
Chemical Society Reviews is the leading journal of the Royal Society of Chemistry for reviews and it currently has an impact factor of 38.618. Read the article on the Chem Soc Rev journal web-site.
Lucas Thuillier joined our research group as a placement student from ESCOM
22 May 2017
We welcome Lucas Thuillier, a third year undergraduate from ESCOM (France), who joined our research group at the School of Mathematics and Physical Sciences (Chemistry) at the University of Hull for a summer research placement. École Supérieure de Chimie Organique et Minérale (ESCOM) is a French grande école in Compiègne, France. Lucas arrived at Hull at the end of May 2017 to undertake 4 months research project in our group as a part of his ESCOM Masters degree course. He will be exploring the properties of emulsions stabilized by cyclodextrins.
Key review: Colloid particle formulations for antimicrobial applications
12 May 2017
Prof Paunov’s research group has just published a key review article in the Elsevier journal Advances in Colloid and Interface Science. This review focuses on various inorganic, organic and hybrid nanoparticles, and discussed their methods of preparation, mechanisms of antimicrobial action and applications. Main highlights are:
- We follow nanotechnology approaches that can potentially bypass antimicrobial resistance
- Review of nanoparticles of universal antibacterial, antifungal and antiviral action
- Mechanisms by which nanoparticles attack microbial cells or inhibit their growth
- Recent developments for targeted delivery of nanoparticle antimicrobials
- Using colloid antibodies for microbial cell shape and surface recognition
- Environmentally benign nanoparticles as a safer-by-design green antimicrobial nanomaterials.
Read the article on the ACIS journal web-site.
Fanny Schnetz joined our research group as a placement student from ENSCR
24 April 2017
Fanny Schnetz joined our research group as a placement student from Ecole Nationale Superieure de Chimie de Rennes (E.N.S.C.R.), a leading Chemical Engineering School in Rennes, France.
Fanny arrived at the University of Hull at the end of April 2017 to undertake 4 months research project in our interdisciplinary group as a part of her Masters degree in Chemistry and Engineering. She will be working on a new type of nanocarriers for antimicrobial applications.
Professor Paunov poster gets a prestigious award at the MRS Spring Meeting at Phoenix, Arizona
18 April 2017
Our poster presentation entitled “Cyclodextrin Stabilised Emulsions, Cyclodextrinosomes and Cyborg Cells” (authors: Baghali Mathapa and Vesselin Paunov) was given a recognition award as a best poster at the Symposium SM8 – Advanced Polymers at the Materials Research Society Spring Meeting in Phoenix, AZ, 17-21 April 2017.
MRS meetings are highly interdisciplinary and consist of more than 60 parallel symposia with 3 joint poster sessions. MRS Spring meeting this year was attended by over 10,000 participants.
Three visiting students from ESCOM join our reserach group for a summer placement
1 June 2016
We welcome to our research group three visiting students from ESCOM (Chemical Engineering School in Compiegne, France).
Déborah Legrand, Mimôzà Ralaivoay and Laura Floury (from left to right) arrived at the University of Hull at the end of May 2016 to undertake short research projects in our group as a part of their Masters degree in Chemistry. The trio will join the current group members in pioneering research which will help them develop their scientific skills and gain vital experience in multi-disciplinary backgrounds.
Déborah will be working on a new method for preparation of cell spheroids with applications in bioprinting and tissue engineering. Mimôzà will work on a project involving cell imprinting and recognition technology. Laura will be involved in a project developing a new generation of optical brighteners.
Their internships will end in September 2016, when the students will produce a detailed report upon successful completion of their projects. This placement visit is expected to be the first of many in a fruitful relationship between the Paunov Research Group at the University of Hull and ESCOM (Compiegne, France).
Congratulations to Emmanuel Ubuo for successfully defending his PhD thesis
23 May 2016
Congratulations to Emmanuel Ubuo who successfully passed his PhD viva on 23 May 2016 with recommendation for only minor corrections.
Emmanuel has been a member of Prof Paunov’s and Dr Horozov’s research groups for more than 3 years. His PhD thesis is entitled “WETTING PROPERTIES OF PROTECTIVE COATINGS BASED ON STRUCTURED SURFACES”. He was jointly supervised by Prof Paunov and Dr Horozov.
Emmanuel developed important insights about wetting of structured and partially impregnated porous surfaces and has been working on the self-healing coatings for antibiofouling and corrosion inhibition applications.
Emmanuel’s PhD was funded by the Nigerian Tertiary Education Trust Fund (TETFund) and Akwa Ibom State University, Nigeria where Emmanuel will continue his work as a Lecturer.
Professor Paunov and his team granted the prestigious Pioneer Award from Cancer Research UK
14 April 2016
Professor Vesselin Paunov and Dr Leigh Madden at the Faculty of Science and Engineering of the University of Hull and Dr David Allsup, a clinical hematologist consultant from the Queens Oncology Centre at Castle Hill Hospital, were recently granted the prestigious Pioneer Award from Cancer Research UK to work on a novel in-vitro technology for removal of malignant blood cancer cells from blood samples of acute myeloma leukaemia (AML) patients based on bioimprinting and cell shape recognition.
Bioimprints are physical copies of the cell surface produced by casting the myeloblast cells with polymers and other materials. The cell shape recognition is based on the increased area of contact of target myeloblast cells with their negative replica on the bioimprinted surface.
This cell shape recognition technology would potentially allow Paunov’s team to develop a device which can separate in-vitro the malignant myeloblasts from the normal white blood cells. Such cell shape sorter could deplete further the blood of AML patients from myeloblasts after chemotherapy which may potentially improve their prognosis and reduce AML relapses based on the counts of minimal residual disease.
Our Hull team was one of the five awarded the Pioneer Award at this round along with other teams from the Universities of Cambridge, Oxford, Manchester and the Institute of Cancer Research – London.
Read more about this on the Cancer Research UK science blog.
Professor Paunov’s research mentioned in a highlight by the editor of Journal of Materials Chemistry B
3 April 2016
Professor Paunov was recently praised in a highlight by the Associate Editor of Journal of Materials Chemistry B, Prof Marc in het Panhuis, for the inspiration that he got from him more than 10 years ago which opened Marc’s research to novel biomaterials produced by microorganisms. Back in 2003 Professor Paunov was working with gellan gum and developed the gel trapping technique for measuring contact angles of colloid particles at a liquid surface as well as colloidosomes with gelled cores and Janus particles.
Gellan gum is a polysaccharide produced by a bacterium and it can form hydrogels at very low concentrations. A brief collaboration between Marc and Vesko at the University of Hull at this time led to a novel method for dispersing carbon nanotubes in aqueous solutions as it turned out that gellan also has stabilizing properties – you can read more about this research here.
Marc has been fascinated by the properties of gellan and has been using it in his research group at the University of Wollongong, Australia, inventing different ways to formulate innovative 3D printable biomaterials and soft robotics based on hydrogels.
Read the highlight.
Congratulations to Mohammed Al-Awady for successfully passing his PhD viva
16 February 2016
We are all happy for Mohammed Al-Awady who successfully defended his PhD thesis and passed his viva with recommendation for only minor corrections.
Mohammed has been a member of Prof Paunov’s research group for more than 4 years and his PhD thesis was entitled “Nanoparticles Mediated Toxicity and Antimicrobial Actions”. He was jointly supervised by Prof Paunov and Prof Greenway.
He made a valuable contribution towards better understanding of the role of the particle size and surface charge on the nanotoxicity of titania nanoparticles.
Mohammed Al-Awady will continue his work as a Lecturer at the University of Babylon.
Ahmed Al-Mamoori joins Paunov Research Group for a PhD study
28 September 2015
Warm welcome to our new PhD student Ahmed Al-Mamoori who joined Paunov Research Group at the University of Hull in September 2015. Ahmed’s PhD project involves using synthetic colloids as antimicrobial agents.
Ahmed Al-Mamoori received his BSc in Chemistry in 2005 and MSc in Photochemistry in 2012, both from the Department of Chemistry of the University of Babylon, Iraq under the supervision of Prof. Falah H. Hussein. He also specialized at the Department of Photocatalysis and Nanotechnology, Institute of Technical Chemistry, University of Hannover, Germany with Prof. Bahnemann in 2011. Since 2012 he joined the University of Babylon as an Assistant Lecturer.
Hamza Al-Shehri successfully defends his PhD thesis
21 September 2015
Congratulations to Hamza Al-Shehri, who passed his PhD viva. Hamza was a member of Prof Paunov research group since 2011. His PhD thesis is entitled “Wettability of Anisotropic and Porous Particles Adsorbed at Fluid Interfaces”.
Baghali Mathapa poster wins the Best Poster Prize at ECIS 2015
11 September 2015
Congratulations to our alumni group member Dr Baghali Mathapa, whose poster entitled “Self-assembly of cyclodextrins at fluid interfaces: Surfactant-free emulsions, cyclodextrinosomes and cyclodextrin-functionalised living cells” won the “Best Poster” award at the European Colloid and Interface Society annual meeting Bordeaux, 6-11 September 2015.
ECIS 2015 is a major meeting of the colloid scientist from Europe and around the world more than 700 participants. Dr Mathapa is currently working as a lecturer at Botswana Agricultural College after finishing his PhD in the research group of Prof. Paunov. Baghali’s poster was based on results published in his PhD thesis.
Scientists Go Green with Environmentally Friendly Antimicrobial Nanoparticles
13 July 2015
Researchers have engineered nanoscale antimicrobial particles using green chemistry principles in their design, producing an environmentally benign ‘nanobullet’ which attacks dangerous bacteria and neutralizes them.
An Environmentally Benign Antimicrobial Nanoparticle Based on a Silver-Infused Lignin Core – published in Nature Nanotechnology (13 July 2015).
Vesselin Paunov, a Professor of Physical Chemistry and Advanced Materials at the University of Hull, was one of the researchers collaborating on this project along with international teams of Prof Velev at North Carolina State University, staff from the US Environmental Protection Agency and UCL.
“Silver nanoparticles have great antibacterial properties, but after their use they can persist in the environment.” explains Prof Paunov. “However, it is not necessary for the entire nanoparticles to be made of silver. We produced nanoparticles from lignin (an essential component in plants) which we infused with silver ions and coated with a layer of polymer which adheres well to bacteria to form a biodegradable and green alternative to silver metal nanoparticles.”
“When the silver-infused lignin nanoparticles adhere to bacterial cells, the silver ions kill them very efficiently, leaving the depleted lignin cores to biodegrade as lignin from plant cells, which cuts the pollution risk to the environment. Our green nanotechnology, which is benign by design, and could lead to enhanced efficiency of antimicrobial products used in agriculture, home and personal care.”
The researchers used these complex nanoparticles to attack E.coli which causes food poisoning, Pseudomonas aeruginosa, a common disease causing bacterium and Ralstonia, a genus of bacteria containing soil-borne pathogen species. They also targeted Staphylococcus epidermis, a bacterium that can cause harmful biofilms on plastics, like catheters, in the human body. The silver-infused lignin nanoparticles were effective against all of the bacteria.
Prof Paunov invited to give Keynote Lecture at the ECIS 2015
6 July 2015
Professor Paunov was invited to present a Keynote Lecture at the European Colloid Society (ECIS) Annual Conference in Bordeaux, 6-11 September 2015. ECIS is a major meeting of the colloid scientist from Europe and around the world more than 700 participants. His talk will be on Nanotoxicity of Polyelectrolyte coated Titania Nanoparticles.
Synthetic Colloids with Antimicrobial Action
1 June 2014
Prof Vesselin Paunov and Dr Anupam Das published an invited features article in the online journal Microbiologist (issue June 2014) of the Society of Applied Microbiology about unconventional antimicrobial agents based on colloid particles.
Cell Surface Engineering book
24 July 2014
Prof Vesselin Paunov, Dr Rawil Fakhrullin and Dr Anupam Das contributed a Chapter on “Artificial multicellular assemblies from cells interfaced with polymers and nanomaterials” in the recently published RSC book Cell Surface Engineering, edited by Prof. Yuri Lvov, Prof. Insung Choi and Dr Fakhrullin.
In this chapter we review the recent developments in fabrication of multicellular assemblies from cells modified with polymers and nanomaterials. We focus on the specific properties of such “cyborg” cells which allow a variety of new methods to be used for their assembly into multicellular structures with functions rather different from those of the original cells. We discuss template and external field mediated assembly of modified cells as well as various techniques for preparation of tissue spheroids and polyelectrolyte mediated cell assemblies. Numerous applications of such cell assemblies in tissue engineering, bioprinting, biosensing and bioelectronics are outlined and commented throughout the chapter.
Take a look at the contents page at the RSC web-site.
Fighting microbes without antibiotics
29 March 2013
The team of scientists at the University of Hull led by Professor Paunov have recently developed a new family of selective antimicrobial agents which could hold the key to fighting microbes without the use of traditional antibiotics. They discovered a way of custom-designing microparticles to recognise the shape of specific microbes and ‘de-activate’ them [1-2].
“This idea has many applications, as it allows killing microbes selectively without antibiotics. Since many superbugs have developed resistance to the available antibiotics, this technology may help us to build the next lines of defence from resistant microbial infections.” says Professor Paunov.
Professor Paunov’s team have created innovative antimicrobial agents by using the microbes as templates. First, they coated the target microbes with very tiny gold particles and thin shells of silica, the same material as ordinary sand.
They broke those shells in large fragments which “remember” the shape of the templated microbial cells, so when they encounter cells that match their shape they bind to them selectively. The researchers named these particles “colloid antibodies” as they recognise whole cells.
When the researchers incubated colloid antibodies with a mixture of different microbes, they bind only to the original cells and bring gold particles directly on their surface.
Since gold nanoparticles absorb light strongly, shining a laser on the mixture makes them heat up and kill the cells in contact. The cells that do not “fit” into the shape imprinted in the colloid antibodies remain unaffected.
Their work was published in the Journal of the American Chemical Society and highlighted by the American Chemical Society and BBSRC Business magazine.
- Borovicka, J., Stoyanov, S.D., Paunov, V.N., Shape recognition of microbial cells by colloidal cell imprints, Nanoscale, 57 (2013) 8560 – 8568.
- Borovicka, J., Metheringham, J., Madden, L.A., Walton C.D., Stoyanov, S.D., Paunov, V.N., “Photothermal colloid antibodies for shape-selective recognition and killing of microorganisms.”, J. Am. Chem. Soc., 135 (2013), 5282-5285. [Highlighted by ACS Press]
Scientists engineer cyborg cells in the fight against pathogens, poisons and pollutants
16 April 2012
We have all watched sci-fi movies with robots and cyborgs that are stronger than humans. Some of us have played computer games with special goggles that replace our environment with virtual reality. Now imagine if we can make cyborgs out of single cells. It sounds like something from the distant future but actually it is already a reality which started more than five years ago in a research lab at the University of Hull.
Professor Vesselin Paunov, who leads a team of biomaterials experts in the Department of Chemistry, succeeded in turning ordinary cells like baker’s yeast into ‘cyborg cells’. The researchers managed to ‘wrap’ the cells with special polymers and very tiny particles while keeping them alive [1-4].
“The cells interact with their environment through their cell membrane,” explains Professor Paunov.
“If we furnish the cells with an artificial interface by coating them with certain particles or polymers, they can perform completely new roles. For the cells, this artificial interface looks like putting on virtual reality goggles. We can use these cells to build useful devices, such as detecting pollution and even fighting microbes.”
- Fakhrullin, R.F., Garcia-Alonso, J., Paunov, V.N., “A Direct technique for preparation of magnetically functionalized living yeast cells”, Soft Matter, 6 (2010) 391-397.
- Garcia-Alonso, J, Fakhrullin, R. F., Paunov, V.N., “Rapid and direct magnetization of GFP-reporter yeast for micro-screening systems”, Biosensors and Bioelectronics, 25 (2010) 1816-1819.
- Zhang, D., Fakhrullin, R.F., Özmen, M., Wang, H., Wang, J., Paunov, V.N., Li, G., Huang, W.E., “Functionalization of whole-cell bacterial reporters with magnetic nanoparticles”, Microbial Biotechnology, 4 (2011) 89-97.
- Fakhrullin, R. F., Zamaleeva, A.I., Minullina, Renata T., Paunov, V.N.,”Cyborg cells: functionalisation of living cells with polymers and nanomaterials”, Chemical Society Reviews, 41 (2012) 4189-4206.
Detecting toxins and pollutants with magnetic yeast
6 October 2010
A team of scientists from the University of Hull, including Prof Paunov and Prof Greenway have used magnetic nanoparticles to make magnetic yeast, whose cells can be moved around and extracted from solution with a strong magnet.
They magnetised a special strain of yeast cells, then trapped them in a device called a ‘lab-on-a-chip’ – a device which shrinks the pipettes, test tubes and analysis instruments of a modern chemistry lab onto a microchip-sized wafer of plastic. The tiny lab-on-a-chip has many ingrained grooved channels, and the magnetic cells are held in these channels with a magnet .
Using the lab-on-a-chip device, different liquid samples can be quickly screened for toxicity by flowing them over the cells in the channels. The yeast cells look fluorescent under a microscope when they are exposed to genotoxins as they activate their DNA-repair gene which triggers another gene that produces green fluorescent protein.
“We also collaborated with colleagues at the University of Sheffield to detect environmental pollution using bacterial cyborg cells. Mixing them with polluted soil gets them exposed to the pollutants trapped in the pores of the soil particles. When collected back with a magnet and examined, the way the cells respond tells us how concentrated the pollutant is.”
- García-Alonso, J. Fakhrullin, R.F., Greenway, G.M., Haswell, S.J., Hardege, J.D., Pamme, N., Shen, Z., Paunov, V.N., “Toxicity screening tool utilizing magnetic yeast and gradient mixing”, Analytical and Bioanalytical Chemistry, 400 (2011) 1009-1013.