Co-reporter:Nicolas Perez-Soto;Lauren Moule;Daniel N. Crisan;Ignacio Insua;Leanne M. Taylor-Smith;Kerstin Voelz;Anne Marie Krachler
Chemical Science (2010-Present) 2017 vol. 8(Issue 8) pp:5291-5298
Publication Date(Web):2017/07/24
DOI:10.1039/C7SC00615B
Here we report the first application of non-bactericidal synthetic polymers to modulate the physiology of a bacterial pathogen. Poly(N-[3-(dimethylamino)propyl] methacrylamide) (P1) and poly(N-(3-aminopropyl)methacrylamide) (P2), cationic polymers that bind to the surface of V. cholerae, the infectious agent causing cholera disease, can sequester the pathogen into clusters. Upon clustering, V. cholerae transitions to a sessile lifestyle, characterised by increased biofilm production and the repression of key virulence factors such as the cholera toxin (CTX). Moreover, clustering the pathogen results in the minimisation of adherence and toxicity to intestinal epithelial cells. Our results suggest that the reduction in toxicity is associated with the reduction to the number of free bacteria, but also the downregulation of toxin production. Finally we demonstrate that these polymers can reduce colonisation of zebrafish larvae upon ingestion of water contaminated with V. cholerae. Overall, our results suggest that the physiology of this pathogen can be modulated without the need to genetically manipulate the microorganism and that this modulation is an off-target effect that results from the intrinsic ability of the pathogen to sense and adapt to its environment. We believe these findings pave the way towards a better understanding of the interactions between pathogenic bacteria and polymeric materials and will underpin the development of novel antimicrobial polymers.
Co-reporter:Daniel N. Crisan;Oliver Creese;Ranadeb Ball;Jose Luis Brioso;Ben Martyn;Javier Montenegro
Polymer Chemistry (2010-Present) 2017 vol. 8(Issue 31) pp:4576-4584
Publication Date(Web):2017/08/08
DOI:10.1039/C7PY00535K
Here we present the synthesis and post-polymerisation modification of poly(acryloyl hydrazide), a versatile scaffold for the preparation of functional polymers: poly(acryloyl hydrazide) was prepared from commercially available starting materials in a three step synthesis on a large scale, in good yields and high purity. Our synthetic approach included the synthesis of a Boc-protected acryloyl hydrazide, the preparation of polymers via RAFT polymerisation and the deprotection of the corresponding Boc-protected poly(acryloyl hydrazide). Post-polymerisation modification of poly(acryloyl hydrazide) was then demonstrated using a range of conditions for both hydrophilic and hydrophobic aldehydes. These experiments demonstrate the potential of poly(acryloyl hydrazide) as a scaffold in the synthesis of functional polymers, in particular those applications where in situ screening of the activity of the functionalised polymers may be required (e.g. biological applications).
Co-reporter:Ignacio Insua, Evangelos Liamas, Zhenyu Zhang, Anna F. A. Peacock, Anne Marie Krachler and Francisco Fernandez-Trillo
Polymer Chemistry 2016 vol. 7(Issue 15) pp:2684-2690
Publication Date(Web):16 Mar 2016
DOI:10.1039/C6PY00146G
Here we present new enzyme-responsive polyion complex (PIC) nanoparticles prepared from antimicrobial poly(ethylene imine) and an anionic enzyme-responsive peptide targeting Pseudomonas aeruginosa's elastase. The synthetic conditions used to prepare these nanomaterials allowed us to optimise particle size and charge, and their stability under physiological conditions. We demonstrate that these enzyme responsive PIC nanoparticles are selectively degraded in the presence of P. aeruginosa elastase without being affected by other endogenous elastases. This enzyme-responsive PIC particle can exert an elastase-specific antimicrobial effect against P. aeruginosa without affecting non-pathogenic strains of these bacteria. These targeted enzyme-responsive PIC nanoparticles constitute a novel platform for the delivery of antimicrobial peptides and polymers, and can be a powerful tool in the current race against antimicrobial resistance.
Co-reporter:Emma Leire, Sandra P. Amaral, Iria Louzao, Klaus Winzer, Cameron Alexander, Eduardo Fernandez-Megia and Francisco Fernandez-Trillo
Biomaterials Science 2016 vol. 4(Issue 6) pp:998-1006
Publication Date(Web):29 Apr 2016
DOI:10.1039/C6BM00079G
Here, we evaluate how cationic gallic acid-triethylene glycol (GATG) dendrimers interact with bacteria and their potential to develop new antimicrobials. We demonstrate that GATG dendrimers functionalised with primary amines in their periphery can induce the formation of clusters in Vibrio harveyi, an opportunistic marine pathogen, in a generation dependent manner. Moreover, these cationic GATG dendrimers demonstrate an improved ability to induce cluster formation when compared to poly(N-[3-(dimethylamino)propyl]methacrylamide) [p(DMAPMAm)], a cationic linear polymer previously shown to cluster bacteria. Viability of the bacteria within the formed clusters and evaluation of quorum sensing controlled phenotypes (i.e. light production in V. harveyi) suggest that GATG dendrimers may be activating microbial responses by maintaining a high concentration of quorum sensing signals inside the clusters while increasing permeability of the microbial outer membranes. Thus, the reported GATG dendrimers constitute a valuable platform for the development of novel antimicrobial materials that can target microbial viability and/or virulence.
Co-reporter:Ignacio Insua, Andrew Wilkinson, Francisco Fernandez-Trillo
European Polymer Journal 2016 Volume 81() pp:198-215
Publication Date(Web):August 2016
DOI:10.1016/j.eurpolymj.2016.06.003
Oppositely charged polyions can self-assemble in solution to form colloidal polyion complex (PIC) particles. Such nanomaterials can be loaded with charged therapeutics such as DNA, drugs or probes for application as novel nanomedicines and chemical sensors to detect disease markers. A comprehensive discussion of the factors affecting PIC particle self-assembly and their response to physical and chemical stimuli in solution is described herein. Finally, a collection of key examples of polyionic nanoparticles for biomedical applications is discussed to illustrate their behaviour and demonstrate the potential of PIC nanoparticles in medicine.Figure optionsDownload full-size imageDownload as PowerPoint slide
Co-reporter:Juan M. Priegue;Daniel N. Crisan;Dr. José Martínez-Costas;Dr. Juan R. Granja;Dr. Francisco Fernez-Trillo;Dr. Javier Montenegro
Angewandte Chemie International Edition 2016 Volume 55( Issue 26) pp:7492-7495
Publication Date(Web):
DOI:10.1002/anie.201601441
Abstract
A new method is reported herein for screening the biological activity of functional polymers across a consistent degree of polymerization and in situ, that is, under aqueous conditions and without purification/isolation of candidate polymers. In brief, the chemical functionality of a poly(acryloyl hydrazide) scaffold was activated under aqueous conditions using readily available aldehydes to obtain amphiphilic polymers. The transport activity of the resulting polymers can be evaluated in situ using model membranes and living cells without the need for tedious isolation and purification steps. This technology allowed the rapid identification of a supramolecular polymeric vector with excellent efficiency and reproducibility for the delivery of siRNA into human cells (HeLa-EGFP). The reported method constitutes a blueprint for the high-throughput screening and future discovery of new polymeric functional materials with important biological applications.
Co-reporter:Juan M. Priegue;Daniel N. Crisan;Dr. José Martínez-Costas;Dr. Juan R. Granja;Dr. Francisco Fernez-Trillo;Dr. Javier Montenegro
Angewandte Chemie International Edition 2016 Volume 55( Issue 26) pp:
Publication Date(Web):
DOI:10.1002/anie.201604083
Co-reporter:Juan M. Priegue;Daniel N. Crisan;Dr. José Martínez-Costas;Dr. Juan R. Granja;Dr. Francisco Fernez-Trillo;Dr. Javier Montenegro
Angewandte Chemie 2016 Volume 128( Issue 26) pp:
Publication Date(Web):
DOI:10.1002/ange.201604083
Co-reporter:Juan M. Priegue;Daniel N. Crisan;Dr. José Martínez-Costas;Dr. Juan R. Granja;Dr. Francisco Fernez-Trillo;Dr. Javier Montenegro
Angewandte Chemie 2016 Volume 128( Issue 26) pp:7618-7621
Publication Date(Web):
DOI:10.1002/ange.201601441
Abstract
A new method is reported herein for screening the biological activity of functional polymers across a consistent degree of polymerization and in situ, that is, under aqueous conditions and without purification/isolation of candidate polymers. In brief, the chemical functionality of a poly(acryloyl hydrazide) scaffold was activated under aqueous conditions using readily available aldehydes to obtain amphiphilic polymers. The transport activity of the resulting polymers can be evaluated in situ using model membranes and living cells without the need for tedious isolation and purification steps. This technology allowed the rapid identification of a supramolecular polymeric vector with excellent efficiency and reproducibility for the delivery of siRNA into human cells (HeLa-EGFP). The reported method constitutes a blueprint for the high-throughput screening and future discovery of new polymeric functional materials with important biological applications.
Co-reporter:Javier Monzó, Ignacio Insua, Francisco Fernandez-Trillo and Paramaconi Rodriguez
Analyst 2015 vol. 140(Issue 21) pp:7116-7128
Publication Date(Web):11 Aug 2015
DOI:10.1039/C5AN01330E
Electrochemical sensors are powerful tools widely used in industrial, environmental and medical applications. The versatility of electrochemical methods allows for the investigation of chemical composition in real time and in situ. Electrochemical detection of specific biological molecules is a powerful means for detecting disease-related markers. In the last 10 years, highly-sensitive and specific methods have been developed to detect waterborne and foodborne pathogens. In this review, we classify the different electrochemical techniques used for the qualitative and quantitative detection of pathogens. The robustness of electrochemical methods allows for accurate detection even in heterogeneous and impure samples. We present a fundamental description of the three major electrochemical sensing methods used in the detection of pathogens and the advantages and disadvantages of each of these methods. In each section, we highlight recent breakthroughs, including the utilisation of microfluidics, immunomagnetic separation and multiplexing for the detection of multiple pathogens in a single device. We also include recent studies describing new strategies for the design of future immunosensing systems and protocols. The high sensitivity and selectivity, together with the portability and the cost-effectiveness of the instrumentation, enhances the demand for further development in the electrochemical detection of microbes.
Co-reporter:Francisco Fernandez-Trillo, Helen Willcock
European Polymer Journal (February 2017) Volume 87() pp:
Publication Date(Web):February 2017
DOI:10.1016/j.eurpolymj.2017.01.003
Co-reporter:Ignacio Insua, Sieta Majok, Anna F.A. Peacock, Anne Marie Krachler, Francisco Fernandez-Trillo
European Polymer Journal (February 2017) Volume 87() pp:478-486
Publication Date(Web):February 2017
DOI:10.1016/j.eurpolymj.2016.08.023
Co-reporter:Emma Leire, Sandra P. Amaral, Iria Louzao, Klaus Winzer, Cameron Alexander, Eduardo Fernandez-Megia and Francisco Fernandez-Trillo
Biomaterials Science (2013-Present) 2016 - vol. 4(Issue 6) pp:NaN1006-1006
Publication Date(Web):2016/04/29
DOI:10.1039/C6BM00079G
Here, we evaluate how cationic gallic acid-triethylene glycol (GATG) dendrimers interact with bacteria and their potential to develop new antimicrobials. We demonstrate that GATG dendrimers functionalised with primary amines in their periphery can induce the formation of clusters in Vibrio harveyi, an opportunistic marine pathogen, in a generation dependent manner. Moreover, these cationic GATG dendrimers demonstrate an improved ability to induce cluster formation when compared to poly(N-[3-(dimethylamino)propyl]methacrylamide) [p(DMAPMAm)], a cationic linear polymer previously shown to cluster bacteria. Viability of the bacteria within the formed clusters and evaluation of quorum sensing controlled phenotypes (i.e. light production in V. harveyi) suggest that GATG dendrimers may be activating microbial responses by maintaining a high concentration of quorum sensing signals inside the clusters while increasing permeability of the microbial outer membranes. Thus, the reported GATG dendrimers constitute a valuable platform for the development of novel antimicrobial materials that can target microbial viability and/or virulence.
Co-reporter:Nicolas Perez-Soto, Lauren Moule, Daniel N. Crisan, Ignacio Insua, Leanne M. Taylor-Smith, Kerstin Voelz, Francisco Fernandez-Trillo and Anne Marie Krachler
Chemical Science (2010-Present) 2017 - vol. 8(Issue 8) pp:NaN5298-5298
Publication Date(Web):2017/05/16
DOI:10.1039/C7SC00615B
Here we report the first application of non-bactericidal synthetic polymers to modulate the physiology of a bacterial pathogen. Poly(N-[3-(dimethylamino)propyl] methacrylamide) (P1) and poly(N-(3-aminopropyl)methacrylamide) (P2), cationic polymers that bind to the surface of V. cholerae, the infectious agent causing cholera disease, can sequester the pathogen into clusters. Upon clustering, V. cholerae transitions to a sessile lifestyle, characterised by increased biofilm production and the repression of key virulence factors such as the cholera toxin (CTX). Moreover, clustering the pathogen results in the minimisation of adherence and toxicity to intestinal epithelial cells. Our results suggest that the reduction in toxicity is associated with the reduction to the number of free bacteria, but also the downregulation of toxin production. Finally we demonstrate that these polymers can reduce colonisation of zebrafish larvae upon ingestion of water contaminated with V. cholerae. Overall, our results suggest that the physiology of this pathogen can be modulated without the need to genetically manipulate the microorganism and that this modulation is an off-target effect that results from the intrinsic ability of the pathogen to sense and adapt to its environment. We believe these findings pave the way towards a better understanding of the interactions between pathogenic bacteria and polymeric materials and will underpin the development of novel antimicrobial polymers.
