Dr Gabriel Cavalli
Qualifications: BSc (Montevideo), MPhil (Montevideo), PhD (London)
Dr Gabriel Cavalli
Dr. Gabriel Cavalli was born in Montevideo (Uruguay) .He graduated as a Bachelor in Chemistry from the Faculty of Chemistry (Universidad de la Republica, Montevideo) in 1994 followed by a Master in Chemistry (MPhil) in Organic Synthesis and Applied Biocatalysis at the same institution in 1998 sponsored by PEDECIBA. During this period, Gabriel worked under the supervision of Prof. Gustavo Seoane on the use of bacteria for the synthesis of highly functionalised chiral synthons. This was followed by a PhD at the Department of Chemistry Imperial College, London (1988-2002) working on polymer synthesis under the supervision of Dr. Joachim Steinke. His doctoral research on the development of novel polyether supports for synthesis was a crossover between Organic and Polymer Chemistry.
At the end of his PhD, Gabriel went back to Montevideo for a fixed term academic position in Polymer Chemistry (2002-2004) and back again to the UK for postdoctoral research in March 2004. This time Gabriel joined the Basic Technology 4G Research Project "Four Billion Bases a Day: Practical Individual Genome Sequencing" at the School of Chemistry, University of Southampton working in a highly interdisciplinary project under the supervision of Prof Hywel Morgan, Dr. Cameron Neylon and Dr Peter Roach. During his time in Southampton, Gabriel worked on the functionalisation polymeric materials for the synthesis of oligonucleotide and peptide and the attachment of bio-analytically relevant proteins. He also started work on DNA hybridisation on microparticles and on the effect of the solid-support on hybridisation efficiency and selectivity.
Currently at Surrey, Gabriel’s research lies in the interface of polymer synthesis and (bio)nanotechnology as well as functional polymer systems.
When he wants to escape from the world of chemistry Gabriel takes refuge in the performing arts (acting, directing and singing both as a spectator and as a performer, recently exploring stand-up comedy with the first ever Bright Club Guildford), exploring world cuisine, reading history or philosophy (especially Nichiren Daishonin Buddhism) or putting the world to right over a glass of wine and a nice meal with friends (talking, talking, talking). This allows him to go back to his teaching and research with renewed passion while remaining sane (or so he would like to think..).
Research keywords: polymer chemistry, polymer synthesis, polymer nanotechnology, bionanotechnology, nanomedicine,polymer-protein conjugates >polymer-peptide conjugates, polymer-drug conjugates, polymer therapeutics
Gabriel took up his current position in Surrey in August, 2006. His research interests are the synthesis of chemically functional polymers with defined architectures, polymers for biomedical applications (polymer therapeutics and biocidal polymers), bio-inspired polymeric materials (peptide and protein-polymer conjugates) and biocatalytic polymer synthesis. In particular Gabriel is interested in hybrid materials that self-assemble into controlled nanostructures. By conjugation with synthetic polymers, Gabriel’s research aims to control the self-assembly of the peptides and proteins and fine-tune the nanostructures properties to adapt it to novel applications such as reinforced high-performance materials, novel adhesive formulations, novel drug delivery agents, smart biomaterials, biotechnology and synthesis biology.
Gabriel’s group is currently exploring strategies of protein-polymer conjugation to develop nanomedicines for cardiovascular disease in a project funded by the British Heart Foundation (BHF). Recently this project has been highlighted on the BHF website.
Our group has links with the following researchers:
- Prof John Hay, Dr Ernesto Oviedo-Orta, Dr Ian Hamerton, Dr Brendan Howlin, Dr Helen Coley, Prof Mike Bushell, Dr. Claudio Avignone-Rossa, Dr Noel Wardell (FHMS, Surrey).
- Prof. Joseph Keddie (FEPS, Surrey)
- Dr. Cameron Neylon (ISIS Rutherford Appleton Laboratories and School of Chemistry University of Southampton)
- Dr. Karen Edler (Department of Chemistry, University of Bath)
- Dr Aline Miller (Manchester Interdisciplinary Biocentre, University of Manchester)
- Prof. Geoff Hunt (St. Mary's University College)
- Prof Gustavo Seoane, Dr. Alvaro Díaz, Dr. Sonia Rodríguez and Dr. Pilar Menendez (Facultad de Quimica, Universidad de la Republica, Montevideo)
- 'Site-specific, covalent incorporation of Tus, a DNA-binding protein, on ionic-complementary self-assembling peptide hydrogels using transpeptidase Sortase A as a conjugation tool'.
Soft Matter, 9 (29), pp. 6752-6756.doi: 10.1039/c3sm00131hFull text is available at: http://epubs.surrey.ac.uk/791727/
The site-specific conjugation of DNA-binding protein (Tus) to self-assembling peptide FEFEFKFKK was demonstrated. Rheology studies and TEM of the corresponding hydrogels (including PNIPAAm-containing systems) showed no significant variation in properties and hydrogel morphology compared to FEFEFKFKK. Critically, we demonstrate that Tus is accessible within the gel network displaying DNA-binding properties.
- 'Straw N-halamines: Evaluation in single and multistage filtration systems.'.
Carbohydr Polym, England: 92 (2), pp. 1934-1941.
New N-halamines (I-Cl and II-Cl) based on cellulose extracted from rice straw have been evaluated in single and multistage filtration systems against bacteria and viruses. Escherichia coli and Staphylococcus aureus were used as examples of Gram-negative and Gram-positive bacteria respectively while PRD1 bacteriophage was used as an example for viruses. II-Cl has achieved 9 log reductions in viable counts against E. coli in 2h and S. aureus in 1h while it has achieved 7 log reductions against PRD1 in 5h. The particle size of prepared materials was modified as well as the flow rate through the filtration systems. The antimicrobial activity of modified cellulose was proved to be comparable to some synthetic biocidal polymers from the same type in similar water treatment systems.
- 'Examining the thermo-mechanical properties of novel cyanate ester blends through empirical measurement and simulation'.
Reactive and Functional Polymers, 72 (9), pp. 596-605.
Three cyanate ester monomer or oligomer species: 2,2-bis(4-cyanatophenyl) propane 1, 1-1-bis(4-dicyanatophenyl)ethane 2, and the oligomeric phenolic cyanate (Primaset™ PT30) 3, are blended in various ratios to form binary mixtures, formulated with copper(II) acetylacetonate (200 ppm) in dodecylphenol (1% w/v active copper suspension) and cured (2 K/min to 150 °C + 1 h; 2 K/min to 200 °C + 3 h) followed by a post cure (2 K/min to 260 °C + 1 h). Thermal analysis using DSC reveals good agreement with literature data for the homopolymers: typical polymerisation enthalpies of ca. 97-98 kJ/mol. cyanate are obtained for 1 and 2, with slightly lower values (ca. 80-90 kJ/mol.) obtained for Primaset™ PT30. DMTA data show the possibility of using binary blends of the polymers to yield novel materials with similar thermal and mechanical properties to Primaset™ PT30, while improving the processability of the more highly aromatic oligomer. Two of the homopolymers (1 and 2) and a binary (1:1) blend of the same were simulated. Molecular dynamics experiments reveal good agreement with empirical data generated using DSC, DMTA and TGA. © 2012 Elsevier Ltd. All rights reserved.
- 'N-halamines from rice straw'.
Cellulose, 19 (1), pp. 209-217.Full text is available at: http://epubs.surrey.ac.uk/7442/
The cellulosic part of rice straw was modified to develop N-halamine derivatives for disinfection. The process involved cross-linking of the cellulosic material with amino/amide/imide containing compounds; cyclic and acyclic. The structures of the prepared materials were identified using FTIR and solid state 13CNMR. The modified materials were halogenated to form N-halamines and the antimicrobial activity of each evaluated against examples of Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) using a variety of methods; agar plate, blended agar, stirred flask and in columns. One of the N-halamines achieved a 9 log reduction against both E. coli and S. aureus in 4 h. In addition, no S. aureus growth was recorded on agar plates blended with 0.5 g of this same material.
- 'Quantifying the Effect of Polymer Blending through Molecular Modelling of Cyanurate Polymers.'.
PLoS One, United States: 7 (9)Full text is available at: http://epubs.surrey.ac.uk/769624/
Modification of polymer properties by blending is a common practice in the polymer industry. We report here a study of blends of cyanurate polymers by molecular modelling that shows that the final experimentally determined properties can be predicted from first principles modelling to a good degree of accuracy. There is always a compromise between simulation length, accuracy and speed of prediction. A comparison of simulation times shows that 125ps of molecular dynamics simulation at each temperature provides the optimum compromise for models of this size with current technology. This study opens up the possibility of computer aided design of polymer blends with desired physical and mechanical properties.
- 'New Approach To Produce Water Free of Bacteria, Viruses, and Halogens in a Recyclable System'.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 77 (3), pp. 847-853.doi: 10.1128/AEM.01645-10Full text is available at: http://epubs.surrey.ac.uk/7417/
- 'Metabolomic Profiling Can Differentiate Between Bactericidal Effects of Free and Polymer Bound Halogen'.
JOURNAL OF APPLIED POLYMER SCIENCE, 119 (2), pp. 709-718.doi: 10.1002/app.32731
- 'Synthesis of beaded poly(vinyl ether) solid supports with unique solvent compatibility'. POLYMER, 51 (14), pp. 2984-2992. . (2010)
- 'Macroscopic N-Halamine Biocidal Polymeric Beads'.
JOURNAL OF APPLIED POLYMER SCIENCE, 116 (4), pp. 2396-2408.doi: 10.1002/app.31774
- 'Optimizing Halogenation Conditions of N-Halamine Polymers and Investigating Mode of Bactericidal Action'.
JOURNAL OF APPLIED POLYMER SCIENCE, 113 (4), pp. 2404-2412.doi: 10.1002/app.30390
- 'Biocidal polymers (II): Determination of biological activity of novel N-halamine biocidal polymers and evaluation for use in water filters'.
REACTIVE & FUNCTIONAL POLYMERS, 68 (10), pp. 1448-1458.Full text is available at: http://epubs.surrey.ac.uk/795822/
- 'Diffractive micro bar codes for encoding of biomolecules in multiplexed assays'.
ANALYTICAL CHEMISTRY, 80 (6), pp. 1902-1909.doi: 10.1021/ac7018574Full text is available at: http://epubs.surrey.ac.uk/800377/
- 'Biocidal polymers (I): Preparation and biological activity of some novel blocidal polymers based on uramil and its azo-dyes'.
REACTIVE & FUNCTIONAL POLYMERS, 68 (1), pp. 248-260.Full text is available at: http://epubs.surrey.ac.uk/795821/
- 'Novel non-PEG derived polyethers as solid supports. 2. Solid-phase synthesis studies'.
Journal of Combinatorial Chemistry, 9 (6), pp. 1012-1027.doi: 10.1021/cc7000887Full text is available at: http://epubs.surrey.ac.uk/795243/
Novel non-PEG derived polyether resins, coined SLURPS (Superior Liquid Uptake Resins for Polymersupported Synthesis), were studied for their performance in solid-phase synthesis. Novel amino functional resins, SLURPS-NH2, were prepared with a loading of up to 8.5 mmol/g and employed successfully in the solid-phase synthesis of Leu-Enkephalin. The peptide was obtained with the same purity when compared to its synthesis with commercial standard poly(dimethyl acrylamide) resins. Furthermore we show loading and cleavage of aromatic carboxylic acids in excellent yield. The advantageous solvent compatibility of our support was demonstrated through the biphasic dihydroxylation of alkenes with OsO4 in t-BuOH/water mixtures producing bound 1,2-diols and synthesis and removal of a bound oxime using ethanol/water mixtures both in excellent yields. Reactions were easily monitored by gel-phase NMR and FTIR. These results show that SLURPS are very well suited for organic transformations using highly polar solvent mixtures and reagents and at much higher loading levels than standard amphiphilic resins of similar solvent compatibility. © 2007 American Chemical Society.
- 'Multistep synthesis on SU-8: Combining microfabrication and solid-phase chemistry on a single material'.
Journal of Combinatorial Chemistry, 9 (3), pp. 462-472.doi: 10.1021/cc060079pFull text is available at: http://epubs.surrey.ac.uk/795244/
SU-8 is an epoxy-novolac resin and a well-established negative photoresist for microfabrication and microengineering. The photopolymerized resist is an extremely highly crosslinked polymer showing outstanding chemical and physical robustness with residual surface epoxy groups amenable for chemical functionalization. In this paper we describe, for the first time, the preparation and surface modification of SU-8 particles shaped as microbars, the attachment of appropriate linkers, and the successful application of these particles to multistep solid-phase synthesis leading to oligonucleotides and peptides attached in an unambiguous manner to the support surface. © 2007 American Chemical Society.
- 'Covalent Attachment of Proteins to Solid Supports and Surfaces via Sortase-Mediated Ligation'.
PLOS ONE, 2 (11) Article number ARTN e1164 Full text is available at: http://epubs.surrey.ac.uk/2605/
- 'Non-PEG-derived polyethers as solid supports. 1. Synthesis, swelling studies, and functionalization'.
Journal of Combinatorial Chemistry, 5 (5), pp. 637-644.doi: 10.1021/cc0200686Full text is available at: http://epubs.surrey.ac.uk/795245/
Novel non-PEG derived polyether resins, coined SLURPS (superior liquid-uptake resins for polymer-supported synthesis), were synthesized by cationic polymerization of vinyl ethers. A functional resin was prepared with excellent control over loading levels. A sequence of synthetic transformations involving the introduction of a Wang linker followed by Mitsunobu functionalization chemistry and cleavage of the bound substrate proceeded quantitatively. These new polymers combine outstanding swelling performance in a wide range of solvents with high chemical stability and tunable loading levels up to 8.5 mmol/g. This combination of desirable features sets them apart from other polymer supports and, in particular, other polyether resins currently investigated for combinatorial chemistry.
- 'Chemoenzymatic synthesis of chiral enones from aromatic compounds'. TETRAHEDRON-ASYMMETRY, 13 (22) Article number PII S0957-4166(02)00682-1 , pp. 2453-2459. . (2002)
- '(S)-Tricarbonyl[(1,2,3,4-eta)-(5R,6S)-1-chloro-5,6-dimethoxycyclohexa-1,3-diene]iron(0)'. ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS, 56, pp. 820-821. . (2000)
- 'Osmylation of chiral cis-cyclohexadienediols'.
NEW JOURNAL OF CHEMISTRY, 23 (5), pp. 549-555.doi: 10.1039/a900732f