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Robertson H, Gresham IJ, Nelson ARJ, Prescott SW, Webber GB, Wanless EJ. Illuminating the nanostructure of diffuse interfaces: Recent advances and future directions in reflectometry techniques. Adv Colloid Interface Sci 2024; 331:103238. [PMID: 38917595 DOI: 10.1016/j.cis.2024.103238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 06/07/2024] [Accepted: 06/13/2024] [Indexed: 06/27/2024]
Abstract
Diffuse soft matter interfaces take many forms, from end-tethered polymer brushes or adsorbed surfactants to self-assembled layers of lipids. These interfaces play crucial roles across a multitude of fields, including materials science, biophysics, and nanotechnology. Understanding the nanostructure and properties of these interfaces is fundamental for optimising their performance and designing novel functional materials. In recent years, reflectometry techniques, in particular neutron reflectometry, have emerged as powerful tools for elucidating the intricate nanostructure of soft matter interfaces with remarkable precision and depth. This review provides an overview of selected recent developments in reflectometry and their applications for illuminating the nanostructure of diffuse interfaces. We explore various principles and methods of neutron and X-ray reflectometry, as well as ellipsometry, and discuss advances in their experimental setups and data analysis approaches. Improvements to experimental neutron reflectometry methods have enabled greater time resolution in kinetic measurements and elucidation of diffuse structure under shear or confinement, while innovation in analysis protocols has significantly reduced data processing times, facilitated co-refinement of reflectometry data from multiple instruments and provided greater-than-ever confidence in proposed structural models. Furthermore, we highlight some significant research findings enabled by these techniques, revealing the organisation, dynamics, and interfacial phenomena at the nanoscale. We also discuss future directions and potential advancements in reflectometry techniques. By shedding light on the nanostructure of diffuse interfaces, reflectometry techniques enable the rational design and tailoring of interfaces with enhanced properties and functionalities.
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Affiliation(s)
- Hayden Robertson
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW 2308, Australia; Soft Matter at Interfaces, Technical University of Darmstadt, Darmstadt D-64289, Germany
| | - Isaac J Gresham
- School of Chemistry, University of Sydney, Sydney, NSW 2006, Australia
| | - Andrew R J Nelson
- Australian Centre for Neutron Scattering, ANSTO, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Stuart W Prescott
- School of Chemical Engineering, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Grant B Webber
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Erica J Wanless
- College of Science, Engineering and Environment, University of Newcastle, Callaghan, NSW 2308, Australia.
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Alobaid AA, Skoda MWA, Harris LK, Campbell RA. Translational use of homing peptides: Tumor and placental targeting. J Colloid Interface Sci 2024; 662:1033-1043. [PMID: 38387365 DOI: 10.1016/j.jcis.2024.02.103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 01/30/2024] [Accepted: 02/12/2024] [Indexed: 02/24/2024]
Abstract
HYPOTHESIS Tissue-specific homing peptides have been shown to improve chemotherapeutic efficacy due to their trophism for tumor cells. Other sequences that selectively home to the placenta are providing new and safer therapeutics to treat complications in pregnancy. Our hypothesis is that the placental homing peptide RSGVAKS (RSG) may have binding affinity to cancer cells, and that insight can be gained into the binding mechanisms of RSG and the tumor homing peptide CGKRK to model membranes that mimic the primary lipid compositions of the respective cells. EXPERIMENTS Following cell culture studies on the binding efficacy of the peptides on a breast cancer cell line, a systematic translational characterization is delivered using ellipsometry, Brewster angle microscopy and neutron reflectometry of the extents, structures, and dynamics of the interactions of the peptides with the model membranes on a Langmuir trough. FINDINGS We start by revealing that RSG does indeed have binding affinity to breast cancer cells. The peptide is then shown to exhibit stronger interactions and greater penetration than CGKRK into both model membranes, combined with greater disruption to the lipid component. RSG also forms aggregates bound to the model membranes, yet both peptides bind to a greater extent to the placental than cancer model membranes. The results demonstrate the potential for varying local reservoirs of peptide within cell membranes that may influence receptor binding. The innovative nature of our findings motivates the urgent need for more studies involving multifaceted experimental platforms to explore the use of specific peptide sequences to home to different cellular targets.
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Affiliation(s)
- Abdulaziz A Alobaid
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, United Kingdom; Department of Pharmaceutics, Faculty of Pharmacy, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait
| | - Maximilian W A Skoda
- ISIS Neutron & Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, United Kingdom
| | - Lynda K Harris
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, United Kingdom; Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9WL, United Kingdom; St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, United Kingdom; Olson Center for Women's Health, University of Nebraska Medical Center, Omaha, NE 68198, United States.
| | - Richard A Campbell
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PL, United Kingdom.
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Hu X, Liao M, Ding K, Wang J, Xu H, Tao K, Zhou F, Lu JR. Neutron reflection and scattering in characterising peptide assemblies. Adv Colloid Interface Sci 2023; 322:103033. [PMID: 37931380 DOI: 10.1016/j.cis.2023.103033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/09/2023] [Accepted: 10/20/2023] [Indexed: 11/08/2023]
Abstract
Self-assemblies of de novo designed short peptides at interface and in bulk solution provide potential platforms for developing applications in many medical and technological areas. However, characterising how bioinspired supramolecular nanostructures evolve with dynamic self-assembling processes and respond to different stimuli remains challenging. Neutron scattering technologies including small angle neutron scattering (SANS) and neutron reflection (NR) can be advantageous and complementary to other state-of-the-art techniques in tracing structural changes under different conditions. With more neutron sources now available, SANS and NR are becoming increasingly popular in studying self-assembling processes of diverse peptide and protein systems, but the difficulty in experimental manipulation and data analysis can deter beginners. This review will introduce the basic theory, general experimental setup and data analysis of SANS and NR, followed by provision of their applications in characterising interfacial and solution self-assemblies of representative peptides and proteins. SANS and NR are remarkably effective in determining the morphological features self-assembled short peptides, especially size and shape transitions as a result of either sequence changes or in response to environmental stimuli, demonstrating the unique capability of NR and SANS in unravelling the interactive processes. These examples highlight the potential of NR and SANS in supporting the development of novel short peptides and proteins as biopharmaceutical candidates in the fight against many diseases and infections that share common features of membrane interactive processes.
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Affiliation(s)
- Xuzhi Hu
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.; Lanzhou Institute of Chemical Physics, Tianshui Middle Road, Lanzhou 730000, Gansu, China
| | - Mingrui Liao
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Ke Ding
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Jiqian Wang
- Centre for Bioengineering and Biotechnology, College of Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Hai Xu
- Centre for Bioengineering and Biotechnology, College of Chemical Engineering, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Kai Tao
- State Key Laboratory of Fluid Power and Mechatronic Systems, Key Laboratory of Advanced Manufacturing Technology of Zhejiang Province, School of Mechanical Engineering, Zhejiang University, Hangzhou 310058, China; Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials, ZJU-Hangzhou Global Scientific and Technological Innovation Centre, Zhejiang University, Hangzhou 311215, China
| | - Feng Zhou
- Lanzhou Institute of Chemical Physics, Tianshui Middle Road, Lanzhou 730000, Gansu, China
| | - Jian R Lu
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK..
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Gong H, Hu X, Zhang L, Fa K, Liao M, Liu H, Fragneto G, Campana M, Lu JR. How do antimicrobial peptides disrupt the lipopolysaccharide membrane leaflet of Gram-negative bacteria? J Colloid Interface Sci 2023; 637:182-192. [PMID: 36701864 DOI: 10.1016/j.jcis.2023.01.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/24/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
HYPOTHESIS It is widely regarded that antimicrobial peptides (AMPs) kill bacteria by physically disrupting microbial membranes and causing cytoplasmic leakage, but it remains unclear how AMPs disrupt the outer membrane (OM) of Gram-negative bacteria (GNB) and then compromise the inner membrane. We hypothesise that different AMPs impose different structural disruptions, with direct implications to their antimicrobial efficacies. EXPERIMENTS The antimicrobial activities of three typical AMPs, including the designed short AMP, G3, and two natural AMPs, melittin and LL37, against E. coli and their haemolytic activities were studied. Lipopolysaccharide (LPS) and anionic di-palmitoyl phosphatidyl glycerol (DPPG) monolayer models were constructed to mimic the outer membrane and inner membrane leaflets of Gram-negative bacteria. The binding and penetration of AMPs to the model lipid monolayers were systematically studied by neutron reflection via multiple H/D contrast variations. FINDING G3 has relatively high antimicrobial activity, low cytotoxicity, and high proteolytic stability, whilst melittin has significant haemolysis and LL37 has weaker antimicrobial activity. G3 could rapidly lyse LPS and DPPG monolayers within 10-20 min. In contrast, melittin was highly active against the LPS membrane, but the dynamic process lasted up to 80 min, with excessive stacking in the OM. LL37 caused rather weak destruction to LPS and DPPG monolayers, leading to massive adsorption on the membrane surface without penetrating the lipid tail region. These findings demonstrate that the rationally designed AMP G3 was well optimised to impose most effective destruction to bacterial membranes, consistent with its highest bactericidal activity. These different interfacial structural features associated with AMP binding shed light on the future development of active and biocompatible AMPs for infection and wound treatments.
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Affiliation(s)
- Haoning Gong
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK; State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Xuzhi Hu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Lin Zhang
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Ke Fa
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Mingrui Liao
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK
| | - Huayang Liu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK
| | | | - Mario Campana
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Jian Ren Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Manchester M13 9PL, UK.
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Hu X, Carter J, Ge T, Liao M, Margaret Stephens A, Mclnnes EF, Padia F, Lu JR. Impacts of chain and head lengths of nonionic alkyl ethoxylate surfactants on cytotoxicity to human corneal and skin cells in agri-spraying processes*. J Colloid Interface Sci 2022; 628:162-173. [DOI: 10.1016/j.jcis.2022.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/19/2022] [Accepted: 08/03/2022] [Indexed: 10/15/2022]
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Hall SCL, Tognoloni C, Campbell RA, Richens J, O'Shea P, Terry AE, Price GJ, Dafforn TR, Edler KJ, Arnold T. The interaction of styrene maleic acid copolymers with phospholipids in Langmuir monolayers, vesicles and nanodiscs; a structural study. J Colloid Interface Sci 2022; 625:220-236. [PMID: 35716617 DOI: 10.1016/j.jcis.2022.03.102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 10/31/2022]
Abstract
HYPOTHESIS Self-assembly of amphipathic styrene maleic acid copolymers with phospholipids in aqueous solution results in the formation of 'nanodiscs' containing a planar segment of phospholipid bilayer encapsulated by a polymer belt. Recently, studies have reported that lipids rapidly exchange between both nanodiscs in solution and external sources of lipids. Outstanding questions remain regarding details of polymer-lipid interactions, factors influencing lipid exchange and structural effects of such exchange processes. Here, the dynamic behaviour of nanodiscs is investigated, specifically the role of membrane charge and polymer chemistry. EXPERIMENTS Two model systems are investigated: fluorescently labelled phospholipid vesicles, and Langmuir monolayers of phospholipids. Using fluorescence spectroscopy and time-resolved neutron reflectometry, the membrane potential, monolayer structure and composition are monitored with respect to time upon polymer and nanodisc interactions. FINDINGS In the presence of external lipids, polymer chains embed throughout lipid membranes, the extent of which is governed by the net membrane charge. Nanodiscs stabilised by three different polymers will all exchange lipids and polymer with monolayers to differing extents, related to the properties of the stabilising polymer belt. These results demonstrate the dynamic nature of nanodiscs which interact with the local environment and are likely to deposit both lipids and polymer at all stages of use.
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Affiliation(s)
- Stephen C L Hall
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK; Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 ODE, UK; ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK.
| | - Cecilia Tognoloni
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Richard A Campbell
- Institut Laue-Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France; Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, UK
| | - Joanna Richens
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Paul O'Shea
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YG, UK
| | - Ann E Terry
- MAX IV Laboratory, Lund University, SE-221 00 Lund, Sweden
| | - Gareth J Price
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Tim R Dafforn
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Karen J Edler
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Thomas Arnold
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK; ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK; Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; European Spallation Source ERIC, P.O Box 176, SE-221 00 Lund, Sweden
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Paracini N, Schneck E, Imberty A, Micciulla S. Lipopolysaccharides at Solid and Liquid Interfaces: Models for Biophysical Studies of the Gram-negative Bacterial Outer Membrane. Adv Colloid Interface Sci 2022; 301:102603. [PMID: 35093846 DOI: 10.1016/j.cis.2022.102603] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 11/18/2022]
Abstract
Lipopolysaccharides (LPSs) are a constitutive element of the cell envelope of Gram-negative bacteria, representing the main lipid in the external leaflet of their outer membrane (OM) lipid bilayer. These unique surface-exposed glycolipids play a central role in the interactions of Gram-negative organisms with their surrounding environment and represent a key element for protection against antimicrobials and the development of antibiotic resistance. The biophysical investigation of a wide range of different types of in vitro model membranes containing reconstituted LPS has revealed functional and structural properties of these peculiar membrane lipids, providing molecular-level details of their interaction with antimicrobial compounds. LPS assemblies reconstituted at interfaces represent a versatile tool to study the properties of the Gram-negative OM by exploiting several surface-sensitive techniques, in particular X-ray and neutron scattering, which can probe the structure of thin films with sub-nanometer resolution. This review provides an overview of different approaches employed to investigate structural and biophysical properties of LPS, focusing on studies on Langmuir monolayers of LPS at the air/liquid interface and a range of supported LPS-containing model membranes reconstituted at solid/liquid interfaces.
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Affiliation(s)
| | - Emanuel Schneck
- Physics Departent, Technische Universität Darmstadt, Darmstadt, Germany
| | - Anne Imberty
- Université Grenoble Alpes, CNRS, CERMAV, Grenoble, France
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Hadianamrei R, Wang J, Brown S, Zhao X. Rationally designed cationic amphiphilic peptides for selective gene delivery to cancer cells. Int J Pharm 2022; 617:121619. [PMID: 35218898 DOI: 10.1016/j.ijpharm.2022.121619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 02/14/2022] [Accepted: 02/21/2022] [Indexed: 10/19/2022]
Abstract
Gene therapy has gained increasing attention as an alternative to pharmacotherapy for treatment of various diseases. The extracellular and intracellular barriers to gene delivery necessitate the use of gene vectors which has led to the development of myriads of gene delivery systems. However, many of these gene delivery systems have pitfalls such as low biocompatibility, low loading efficiency, low transfection efficiency, lack of tissue selectivity and high production costs. Herein, we report the development of a new series of short cationic amphiphilic peptides with anticancer activity for selective delivery of small interfering RNA (siRNA) and antisense oligodeoxynucleotides (ODNs) to cancer cells. The peptides consist of alternating dyads of hydrophobic (isoleucine (I) or leucine (L)) and hydrophilic (arginine (R) or lysine (L)) amino acids. The peptides exhibited higher preference for transfection of HCT 116 colorectal cancer cells compared to human dermal fibroblasts (HDFs) and induced higher level of gene silencing in the cancer cells. The nucleic acid complexation and transfection efficiency of the peptides was a function of their secondary structure, their hydrophobicity and their C-terminal amino acid. The peptides containing L in their hydrophobic domain formed stronger complexes with siRNA and successfully delivered it to the cancer cells but were unable to release their cargo inside the cells and therefore could not induce any gene silencing. On the contrary, the peptides containing I in their hydrophobic domain were able to release their associated siRNA and induce considerable gene silencing in cancer cells. The peptides exhibited higher selectivity for colorectal cancer cells and induced less gene silencing in fibroblasts compared to the lipid-based commercial transfection reagent DharmaFECT™ 1. The results from this study can serve as a tool for rational design of new peptide-based gene vectors for high selective gene delivery to cancer cells.
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Affiliation(s)
- Roja Hadianamrei
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK
| | - Jiqian Wang
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266555, China
| | - Stephen Brown
- Department of Biomedical Science, University of Sheffield, S10 2TN, UK
| | - Xiubo Zhao
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK; School of Pharmacy, Changzhou University, Changzhou 213164, China.
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Fox LJ, Kelly PP, Humphreys GJ, Waigh T, Lu JR, McBain AJ. Assessing the Risk of Resistance to Cationic Biocides incorporating Realism-based and Biophysical Approaches. J Ind Microbiol Biotechnol 2021; 49:6414534. [PMID: 34718634 PMCID: PMC9113109 DOI: 10.1093/jimb/kuab074] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/27/2021] [Indexed: 12/30/2022]
Abstract
The control of microorganisms is a key objective in disease prevention and in medical, industrial, domestic, and food-production environments. Whilst the effectiveness of biocides in these contexts is well-evidenced, debate continues about the resistance risks associated with their use. This has driven an increased regulatory burden, which in turn could result in a reduction of both the deployment of current biocides and the development of new compounds and formulas. Efforts to balance risk and benefit are therefore of critical importance and should be underpinned by realistic methods and a multi-disciplinary approach, and through objective and critical analyses of the literature. The current literature on this topic can be difficult to navigate. Much of the evidence for potential issues of resistance generation by biocides is based on either correlation analysis of isolated bacteria, where reports of treatment failure are generally uncommon, or laboratory studies that do not necessarily represent real biocide applications. This is complicated by inconsistencies in the definition of the term resistance. Similar uncertainties also apply to cross-resistance between biocides and antibiotics. Risk assessment studies that can better inform practice are required. The resulting knowledge can be utilised by multiple stakeholders including those tasked with new product development, regulatory authorities, clinical practitioners, and the public. This review considers current evidence for resistance and cross-resistance and outlines efforts to increase realism in risk assessment. This is done in the background of the discussion of the mode of application of biocides and the demonstrable benefits as well as the potential risks.
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Affiliation(s)
- Laura J Fox
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, United Kingdom
| | - Paul P Kelly
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, United Kingdom
| | - Gavin J Humphreys
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, United Kingdom
| | - Thomas Waigh
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, United Kingdom
| | - Jian R Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, United Kingdom
| | - Andrew J McBain
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, United Kingdom
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Hadianamrei R, Tomeh MA, Brown S, Wang J, Zhao X. Correlation between the secondary structure and surface activity of β-sheet forming cationic amphiphilic peptides and their anticancer activity. Colloids Surf B Biointerfaces 2021; 209:112165. [PMID: 34715505 DOI: 10.1016/j.colsurfb.2021.112165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/07/2021] [Accepted: 10/16/2021] [Indexed: 01/01/2023]
Abstract
Cancer is one of the main causes of death worldwide. The current cancer treatment strategies often lack selectivity for cancer cells resulting in dose-limiting adverse effects and reduced quality of life. Recently, anticancer peptides (ACPs) have emerged as an alternative treatment with higher selectivity, less adverse effects, and lower propensity for drug resistance. However, most of the current studies on the ACPs are focused on α-helical ACPs and there is lack of systematic studies on β-sheet forming ACPs. Herein we report the development of a new series of rationally designed short cationic amphiphilic β-sheet forming ACPs and their structure activity relationship. The peptides had the general formula (XY1XY2)3, with X representing hydrophobic amino acids (isoleucine (I) or leucine (L)), Y1 and Y2 representing cationic amino acids (arginine (R) or lysine (K)). The cytotoxicity of the designed ACPs in HCT 116 colorectal cancer, HeLa cervical cancer and human dermal fibroblast (HDF) cells was assessed by MTT test. The physicochemical properties of the peptides were characterized by various techniques including RP-HPLC, LC-MS, and Circular Dichroism (CD) spectroscopy. The surface activity of the peptides at the air-water interface and their interaction with the lipid monolayers as models for cell membranes were studied by Langmuir trough. The peptides consisting of I with R and K had selective anticancer activity while the combination of L and R diminished the anticancer activity of the peptides but rendered them more toxic to HDFs. The anticancer activity of the peptides was directed by their surface activity (amphiphilicity) and their secondary structure in hydrophobic surfaces including cancer cell membranes. The selectivity of the peptides for cancer cells was a result of their higher penetration into cancer cell membranes compared to normal cell membranes. The peptides exerted their anticancer activity by disrupting the mitochondrial membranes and eventually apoptosis. The results presented in this study provide an insight into the structure-activity relationship of this class of ACPs which can be employed as guidance to design new ACPs with improved anticancer activity and lower toxicity against normal cells.
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Affiliation(s)
- Roja Hadianamrei
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK
| | - Mhd Anas Tomeh
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK
| | - Stephen Brown
- Department of Biomedical Science, University of Sheffield, S10 2TN, UK
| | - Jiqian Wang
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266555, China
| | - Xiubo Zhao
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK; School of Pharmacy, Changzhou University, Changzhou 213164, China.
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11
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Hadianamrei R, Tomeh MA, Brown S, Wang J, Zhao X. Rationally designed short cationic α-helical peptides with selective anticancer activity. J Colloid Interface Sci 2021; 607:488-501. [PMID: 34509120 DOI: 10.1016/j.jcis.2021.08.200] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/08/2021] [Accepted: 08/30/2021] [Indexed: 02/08/2023]
Abstract
HYPOTHESIS Naturally derived or synthetic anticancer peptides (ACPs) have emerged as a new generation of anticancer agents with higher selectivity for cancer cells and less propensity for drug resistance. Despite the structural diversity of ACPs, α-helix is the most common secondary structure among them. Herein we report the development of a new library of short cationic amphiphilic α-helical ACPs with selective cytotoxicity against colorectal and cervical cancer. EXPERIMENTS The peptides had a general formula C(XXYY)3 with C representing amino acid cysteine (providing a -SH group for molecular conjugation), X representing hydrophobic amino acids (isoleucine (I) or leucine (L)), and Y representing cationic amino acids (arginine (R) or lysine (K)). Two variants of the peptides were synthesized by adding additional Isoleucine residues to the C-terminal and replacing the N-terminal cysteine with LC-propargylglycine (LC-G) to investigate the effect of N-terminal and C-terminal variation on the anticancer activity. The structure and physicochemical properties of the peptides were determined by RP-HPLC, LC-MS and CD spectroscopy. The cytotoxicity of the peptides in different cell lines was assessed by MTT test, cell proliferation assay and mitochondrial damage assay. The mechanism of cell selectivity of the peptides was investigated by studying their interfacial behaviour at the air/water and lipid/water interface using Langmuir trough. FINDINGS The peptides consisting of K residues in their hydrophilic domains exhibited more selective anticancer activity whereas the peptides containing R exhibited strong toxicity in normal cells. The anticancer activity of the peptides was a function of their helical content and their hydrophobicity. Therefore, the addition of two I residues at C-terminal enhanced the anticancer activity of the peptides by increasing their hydrophobicity and their helical content. These two variants also exhibited strong anticancer activity against colorectal cancer multicellular tumour spheroids (MCTS). The higher toxicity of the peptides in cancer cells compared to normal cells was the result of higher penetration into the negatively charged cancer cell membranes, leading to higher cellular uptake, and their cytotoxic effect was mainly exerted by damaging the mitochondrial membranes leading to apoptosis. The results from this study provide a basis for rational design of new α-helical ACPs with enhanced anticancer activity and selectivity.
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Affiliation(s)
- Roja Hadianamrei
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK
| | - Mhd Anas Tomeh
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK
| | - Stephen Brown
- Department of Biomedical Science, University of Sheffield, S10 2TN, UK
| | - Jiqian Wang
- Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), Qingdao 266555, China
| | - Xiubo Zhao
- Department of Chemical and Biological Engineering, University of Sheffield, S1 3JD, UK; School of Pharmacy, Changzhou University, Changzhou 213164, China.
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Unravelling the structural complexity of protein-lipid interactions with neutron reflectometry. Biochem Soc Trans 2021; 49:1537-1546. [PMID: 34240735 DOI: 10.1042/bst20201071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/02/2021] [Accepted: 06/14/2021] [Indexed: 11/17/2022]
Abstract
Neutron reflectometry (NR) is a large-facility technique used to examine structure at interfaces. In this brief review an introduction to the utilisation of NR in the study of protein-lipid interactions is given. Cold neutron beams penetrate matter deeply, have low energies, wavelengths in the Ångstrom regime and are sensitive to light elements. High differential hydrogen sensitivity (between protium and deuterium) enables solution and sample isotopic labelling to be utilised to enhance or diminish the scattering signal of individual components within complex biological structures. The combination of these effects means NR can probe buried structures such as those at the solid-liquid interface and encode molecular level structural information on interfacial protein-lipid complexes revealing the relative distribution of components as well as the overall structure. Model biological membrane sample systems can be structurally probed to examine phenomena such as antimicrobial mode of activity, as well as structural and mechanistic properties peripheral/integral proteins within membrane complexes. Here, the example of the antimicrobial protein α1-purothionin binding to a model Gram negative bacterial outer membrane is used to highlight the utilisation of this technique, detailing how changes in the protein/lipid distributions across the membrane before and after the protein interaction can be easily encoded using hydrogen isotope labelling.
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Ciumac D, Gong H, Campbell RA, Campana M, Xu H, Lu JR. Structural elucidation upon binding of antimicrobial peptides into binary mixed lipid monolayers mimicking bacterial membranes. J Colloid Interface Sci 2021; 598:193-205. [PMID: 33901846 DOI: 10.1016/j.jcis.2021.04.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 11/28/2022]
Abstract
HYPOTHESIS Antimicrobial peptides (AMPs) kill microorganisms by causing structural damage to bacterial membranes. Different microorganisms often require a different type and concentration of an AMP to achieve full microbial killing. We hypothesise that the difference is caused by different membrane structure and composition. EXPERIMENTS Given the complexities of bacterial membranes, we have used monolayers of the binary DPPG/TMCL mixture to mimic the cytoplasmic membrane of Gram-positive bacteria and the binary DPPG/DPPE mixture to mimic the cytoplasmic membrane of Gram-negative bacteria, where DPPG, TMCL and DPPE stand for 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol), 1',3'-bis[1,2-dimyristoyl-sn-glycero-3-phospho]-sn-glycerol, and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine, respectively. A Langmuir trough was specially designed to control the spread lipid monolayers and facilitate neutron reflectivity measurements. FINDINGS Surface pressure-area isotherm analysis revealed that all binary lipid systems mix non-ideally, but mixing is thermodynamically favoured. An increase in the surface pressure encourages demixing, resulting in phase separation and formation of clusters. Neutron reflectivity measurements were undertaken to study the binding of an antimicrobial peptide G(IIKK)4-I-NH2 (G4) to the binary DPPG/TMCL and DPPG/DPPE monolayer mixtures at the molar ratios of 6/4 and 3/7, respectively. The results revealed stronger binding and penetration of G4 to the DPPG/TMCL monolayer, indicating greater affinity of the antimicrobial peptide due to the electrostatic interaction and more extensive penetration into the more loosely packed lipid film. This work helps explain how AMPs attack different bacterial membranes, and the results are discussed in the context of other lipid models and antibacterial studies.
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Affiliation(s)
- Daniela Ciumac
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK
| | - Haoning Gong
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK
| | - Richard A Campbell
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS-20156, 38042 Grenoble, France; Division of Pharmacy and Optometry, University of Manchester, Oxford Road, Stopford Building, Manchester M13 9PT, UK
| | - Mario Campana
- ISIS Neutron Facility, STFC, Chilton, Didcot OX11 0QZ, UK
| | - Hai Xu
- Centre for Bioengineering and Biotechnology, China University of Petroleum, Qingdao, China
| | - Jian R Lu
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, UK.
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14
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Gong H, Hu X, Liao M, Fa K, Ciumac D, Clifton LA, Sani MA, King SM, Maestro A, Separovic F, Waigh TA, Xu H, McBain AJ, Lu JR. Structural Disruptions of the Outer Membranes of Gram-Negative Bacteria by Rationally Designed Amphiphilic Antimicrobial Peptides. ACS APPLIED MATERIALS & INTERFACES 2021; 13:16062-16074. [PMID: 33797891 DOI: 10.1021/acsami.1c01643] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Gram-negative bacteria are covered by both an inner cytoplasmic membrane (IM) and an outer membrane (OM). Antimicrobial peptides (AMPs) must first permeate through the OM and cell wall before attacking the IM to cause cytoplasmic leakage and kill the bacteria. The bacterial OM is an asymmetric bilayer with the outer leaflet primarily composed of lipopolysaccharides (LPSs) and the inner leaflet composed of phospholipids (PLs). Two cationic α-helical AMPs were designed to target Gram-negative bacteria, a full peptide G(IIKK)3I-NH2 (G3), and a hydrophobic lipopeptide C8-G(IIKK)2I-NH2 (C8G2, with C8 denoting the octanoyl chain). LPS dominates OM functions as the first line of defense against antibiotics, thereby reducing drug susceptibility. This work explores how the two AMPs interact with LPS through several carefully chosen OM models that facilitated measurements from solid-state nuclear magnetic resonance (ss-NMR), small-angle neutron scattering (SANS), and neutron reflectivity (NR). The results revealed that G3 molecules bound preferably to the LPS head region and functioned as bridge molecules to reassemble the dislocated lipids into bilayer stacks. In contrast, C8G2 lipopeptides could quickly penetrate into the central region of the OM to cause direct removal of some membrane lipids. Different structural disruptions implicated different antimicrobial efficacies from these AMPs. The demonstration of the structural features underlying different susceptibilities of the OM to AMPs offers a useful route for the future development of strain-specific AMPs against antimicrobial-resistant pathogens.
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Affiliation(s)
- Haoning Gong
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Xuzhi Hu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Mingrui Liao
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Ke Fa
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Daniela Ciumac
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Luke A Clifton
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK
| | - Armando Maestro
- Institute Laue Langevin, 71 Avenue des Martyrs, CS-20156, 38042 Grenoble, France
| | - Frances Separovic
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Thomas A Waigh
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Hai Xu
- State Key Laboratory of Heavy Oil Processing and the Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Andrew J McBain
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Jian Ren Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
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15
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Qian S, Sharma VK, Clifton LA. Understanding the Structure and Dynamics of Complex Biomembrane Interactions by Neutron Scattering Techniques. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:15189-15211. [PMID: 33300335 DOI: 10.1021/acs.langmuir.0c02516] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The membrane is one of the key structural materials of biology at the cellular level. Composed predominantly of a bilayer of lipids with embedded and bound proteins, it defines the boundaries of the cell and many organelles essential to life and therefore is involved in almost all biological processes. Membrane-specific interactions, such as drug binding to a membrane receptor or the interactions of an antimicrobial compound with the lipid matrix of a pathogen membrane, are of interest across the scientific disciplines. Herein we present a review, aimed at nonexperts, of the major neutron scattering techniques used in membrane studies: small-angle neutron scattering, neutron membrane diffraction, neutron reflectometry, quasielastic neutron scattering, and neutron spin echo. Neutron scattering techniques are well suited to studying biological membranes. The nondestructive nature of cold neutrons means that samples can be measured for long periods without fear of beam damage from ultraviolet, electron, or X-ray radiation, and neutron beams are highly penetrating, thus offering flexibility in samples and sample environments. Most important is the strong difference in neutron scattering lengths between the two most abundant forms of hydrogen, protium and deuterium. Changing the relative amounts of protium/deuterium in a sample allows the production of a series of neutron scattering data sets, enabling the observation of differing components within complex membrane architectures. This approach can be as simple as using the naturally occurring neutron contrast between different biomolecules to study components in a complex by changing the solution H2O/D2O ratio or as complex as selectively labeling individual components with hydrogen isotopes. This review presents an overview of each experimental technique with the neutron instrument configuration, related sample preparation and sample environment, and data analysis, highlighted by a special emphasis on using prominent neutron contrast to understand structure and dynamics. This review gives researchers a practical introduction to the often enigmatic suite of neutron beamlines, thereby lowering the barrier to taking advantage of these large-facility techniques to achieve new understandings of membranes and their interactions with other molecules.
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Affiliation(s)
- Shuo Qian
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Veerendra Kumar Sharma
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Luke A Clifton
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, U.K. OX11 0QX
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16
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Gong H, Sani MA, Hu X, Fa K, Hart JW, Liao M, Hollowell P, Carter J, Clifton LA, Campana M, Li P, King SM, Webster JRP, Maestro A, Zhu S, Separovic F, Waigh TA, Xu H, McBain AJ, Lu JR. How do Self-Assembling Antimicrobial Lipopeptides Kill Bacteria? ACS APPLIED MATERIALS & INTERFACES 2020; 12:55675-55687. [PMID: 33259204 DOI: 10.1021/acsami.0c17222] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Antimicrobial peptides are promising alternatives to traditional antibiotics. A group of self-assembling lipopeptides was formed by attaching an acyl chain to the N-terminus of α-helix-forming peptides with the sequence Cx-G(IIKK)yI-NH2 (CxGy, x = 4-12 and y = 2). CxGy self-assemble into nanofibers above their critical aggregation concentrations (CACs). With increasing x, the CACs decrease and the hydrophobic interactions increase, promoting secondary structure transitions within the nanofibers. Antimicrobial activity, determined by the minimum inhibition concentration (MIC), also decreases with increasing x, but the MICs are significantly smaller than the CACs, suggesting effective bacterial membrane-disrupting power. Unlike conventional antibiotics, both C8G2 and C12G2 can kill Staphylococcus aureus and Escherichia coli after only minutes of exposure under the concentrations studied. C12G2 nanofibers have considerably faster killing dynamics and lower cytotoxicity than their nonaggregated monomers. Antimicrobial activity of peptide aggregates has, to date, been underexploited, and it is found to be a very promising mechanism for peptide design. Detailed evidence for the molecular mechanisms involved is provided, based on superresolution fluorescence microscopy, solid-state nuclear magnetic resonance, atomic force microscopy, neutron scattering/reflectivity, circular dichroism, and Brewster angle microscopy.
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Affiliation(s)
- Haoning Gong
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Marc-Antoine Sani
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Xuzhi Hu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Ke Fa
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jack William Hart
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Mingrui Liao
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Peter Hollowell
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jessica Carter
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Luke A Clifton
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - Mario Campana
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - Peixun Li
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - Stephen M King
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - John R P Webster
- ISIS Pulsed Neutron & Muon Source, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, U.K
| | - Armando Maestro
- Institute Laue Langevin, 71 Avenue des Martyrs, CS-20156, Grenoble 38042, France
| | - Shiying Zhu
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Institute, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Thomas A Waigh
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Hai Xu
- State Key Laboratory of Heavy Oil Processing and the Centre for Bioengineering and Biotechnology, China University of Petroleum (East China), 66 Changjiang West Road, Qingdao 266580, China
| | - Andrew J McBain
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jian Ren Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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17
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Gkionis L, Campbell RA, Aojula H, Harris LK, Tirella A. Manufacturing drug co-loaded liposomal formulations targeting breast cancer: Influence of preparative method on liposomes characteristics and in vitro toxicity. Int J Pharm 2020; 590:119926. [PMID: 33010397 DOI: 10.1016/j.ijpharm.2020.119926] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 01/09/2023]
Abstract
Developing more efficient manufacturing methods for nano therapeutic systems is becoming important, not only to better control their physico-chemical characteristics and therapeutic efficacy but also to ensure scale-up is cost-effective. The principle of cross-flow chemistry allows precise control over manufacturing parameters for the fabrication of uniform liposomal formulations, as well as providing reproducible manufacturing scale-up compared to conventional methods. We have herein investigated the use of microfluidics to produce PEGylated DSPC liposomes loaded with doxorubicin and compared their performance against identical formulations prepared by the thin-film method. The isoprenylated coumarin umbelliprenin was selected as a co-therapeutic. Umbelliprenin-loaded and doxorubicin:umbelliprenin co-loaded liposomes were fabricated using the optimised microfluidic set-up. The role of umbelliprenin as lipid bilayer fluidity modulation was characterized, and we investigated its role on liposomes size, size distribution, shape and stability compared to doxorubicin-loaded liposomes. Finally, the toxicity of all liposomal formulations was tested on a panel of human breast cancer cells (MCF-7, MDA-MB 231, BT-474) to identify the most potent formulation by liposomal fabrication method and loaded compound(s). We herein show that the microfluidic system is an alternative method to produce doxorubicin:umbelliprenin co-loaded liposomes, allowing fine control over liposome size (100-250 nm), shape, uniformity and doxorubicin drug loading (>80%). Umbelliprenin was shown to confer fluidity to model lipid biomembranes, which helps to explain the more homogeneous size and shape of co-loaded liposomes compared to liposomes without umbelliprenin. The toxicity of doxorubicin:umbelliprenin co-loaded liposomes was lower than that of free doxorubicin, due to the delayed release of doxorubicin from liposomes. An alternative, rapid and easy manufacturing method for the production of liposomes has been established using microfluidics to effectively produce uniform doxorubicin:umbelliprenin co-loaded liposomal formulations with proven cytotoxicity in human breast cancer cell lines in vitro.
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Affiliation(s)
- Leonidas Gkionis
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester M13 9PL, UK
| | - Richard A Campbell
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester M13 9PL, UK
| | - Harmesh Aojula
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester M13 9PL, UK
| | - Lynda K Harris
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester M13 9PL, UK; Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, 5th floor (Research), St Mary's Hospital, Oxford Road, Manchester M13 9WL, UK; St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester M13 9WL, UK
| | - Annalisa Tirella
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Oxford Road, Manchester M13 9PL, UK.
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18
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Gong H, Liao M, Hu X, Fa K, Phanphak S, Ciumac D, Hollowell P, Shen K, Clifton LA, Campana M, Webster JRP, Fragneto G, Waigh TA, McBain AJ, Lu JR. Aggregated Amphiphilic Antimicrobial Peptides Embedded in Bacterial Membranes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:44420-44432. [PMID: 32909733 DOI: 10.1021/acsami.0c09931] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Molecular dynamics (MD) simulations, stochastic optical reconstruction microscopy (STORM), and neutron reflection (NR) were combined to explore how antimicrobial peptides (AMPs) can be designed to promote the formation of nanoaggregates in bacterial membranes and impose effective bactericidal actions. Changes in the hydrophobicity of the designed AMPs were found to have a strong influence on their bactericidal potency and cytotoxicity. G(IIKK)3I-NH2 (G3) achieved low minimum inhibition concentrations (MICs) and effective dynamic kills against both antibiotic-resistant and -susceptible bacteria. However, a G3 derivative with weaker hydrophobicity, KI(KKII)2I-NH2 (KI), exhibited considerably lower membrane-lytic activity. In contrast, the more hydrophobic G(ILKK)3L-NH2 (GL) peptide achieved MICs similar to those observed for G3 but with worsened hemolysis. Both the model membranes studied by Brewster angle microscopy, zeta potential measurements, and NR and the real bacterial membranes examined with direct STORM contained membrane-inserted peptide aggregates upon AMP exposure. These structural features were well supported by MD simulations. By revealing how AMPs self-assemble in microbial membranes, this work provides important insights into AMP mechanistic actions and allows further fine-tuning of antimicrobial potency and cytotoxicity.
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Affiliation(s)
- Haoning Gong
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Mingrui Liao
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Xuzhi Hu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Ke Fa
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Sorasak Phanphak
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Daniela Ciumac
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Peter Hollowell
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Kangcheng Shen
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Luke A Clifton
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Mario Campana
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - John R P Webster
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Giovanna Fragneto
- Institute of Laue Langevin, 71 Avenue des Martyrs, CS-20156, Grenoble 38042, France
| | - Thomas A Waigh
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Andrew J McBain
- Division of Pharmacy and Optometry, Faculty of Biology, Medicine and Health, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jian Ren Lu
- Biological Physics Laboratory, Department of Physics and Astronomy, Faculty of Science and Engineering, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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19
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Hu X, Pambou E, Gong H, Liao M, Hollowell P, Liu H, Wang W, Bawn C, Cooper J, Campana M, Ma K, Li P, Webster JRP, Padia F, Bell G, Lu JR. How does substrate hydrophobicity affect the morphological features of reconstituted wax films and their interactions with nonionic surfactant and pesticide? J Colloid Interface Sci 2020; 575:245-253. [PMID: 32361410 DOI: 10.1016/j.jcis.2020.04.043] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 01/19/2023]
Abstract
HYPOTHESIS Surfactants are widely used in agri-sprays to improve pesticide efficiency, but the mechanism underlying their interactions with the surface wax film on plants remains poorly understood. To facilitate physical characterisations, we have reconstituted wheat cuticular wax films onto an optically flat silicon substrate with and without octadecyltrimethoxysilane modification to control surface hydrophobicity. EXPERIMENTS Imaging techniques including scanning electron microscopy (SEM) unravelled morphological features of the reconstituted wax films similar to those on leaves, showing little impact from the different substrates used. Neutron reflection (NR) established that reconstituted wax films were comprised of an underlying wax film decorated with top surface wax protrusions, a common feature irrespective of substrate hydrophobicity and highly consistent with what was observed from natural wax films. NR measurements, with the help of isotopic H/D substitutions to modify the scattering contributions of the wax and solvent, revealed different wax regimes within the wax films, illustrating the impact of surface hydrophilicity on the nanostructures within the wax films. FINDINGS It was observed from both spectroscopic ellipsometry and NR measurements that wax films formed on the hydrophobic substrate were more robust and durable against attack by nonionic surfactant C12E6 solubilised with pesticide Cyprodinil (CP) than films coated on the bare hydrophilic silica. Thus, the former could be a more feasible model for studying the wax-surfactant-pesticide interactions.
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Affiliation(s)
- Xuzhi Hu
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Elias Pambou
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Haoning Gong
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Mingrui Liao
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Peter Hollowell
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Huayang Liu
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Weimiao Wang
- Department of Materials and National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Carlo Bawn
- School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Jos Cooper
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Mario Campana
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Kun Ma
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Peixun Li
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - John R P Webster
- STFC ISIS Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, UK
| | - Faheem Padia
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Gordon Bell
- Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, UK
| | - Jian R Lu
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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Matyszewska D, Nazaruk E, Campbell RA. Interactions of anticancer drugs doxorubicin and idarubicin with lipid monolayers: New insight into the composition, structure and morphology. J Colloid Interface Sci 2020; 581:403-416. [PMID: 32771749 DOI: 10.1016/j.jcis.2020.07.092] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/17/2020] [Accepted: 07/18/2020] [Indexed: 12/13/2022]
Abstract
We quantify directly here for the first time the extents of interactions of two different anthracycline drugs with pure and mixed lipid monolayers with respect to the surface pressure and elucidate differences in the resulting interaction mechanisms. The work concerns interactions of doxorubicin (DOx) and idarubicin (IDA) with monolayers of the zwitterionic DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) and negatively charged DMPS (1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (sodium salt)) as well as a 7:3 mixture of the two lipids. These drugs are used in current cancer treatments, while the lipid systems were chosen as phosphocholines are the major lipid component of healthy cell membranes, and phosphoserines are the major lipid component that is externalized into the outer leaflet of cancerous cell membranes. It is shown that DOx interacts with DMPS monolayers to a greater extent than with DMPC monolayers by lower limits of a factor of 5 at a surface pressure of 10 mN/m and a factor of 12 at 30 mN/m. With increasing surface pressure, the small amount of drug (~0.3 µmol/m2) bound to DMPC monolayers is excluded from the interface, yet its interaction with DMPS monolayers is enhanced until there is even more drug (~3.2 µmol/m2) than lipid (~2.6 µmol/m2) at the interface. Direct evidence is presented for all systems studied that upon surface area compression lipid is reproducibly expelled from the monolayer, which we infer to be in the form of drug-lipid aggregates, yet the nature of adsorption of material back to the monolayer upon expansion is system-dependent. At 30 mN/m, most relevant to human physiology, the interactions of DOx and IDA are starkly different. For DOx, there is a conformational change in the interfacial layer driven by aggregation, resulting in the formation of lateral domains that have extended layers of drug. For the more lipophilic IDA, there is penetration of the drug into the hydrophobic acyl chain region of the monolayer and no indication of lateral segregation. In addition to the Langmuir technique, these advances were made as a result of direct measurements of the interfacial composition, structure and morphology using two different implementations of neutron reflectometry and Brewster angle microscopy. The results provide new insight into key processes that determine the uptake of drugs such as limited drug penetration through cell membranes by passive diffusion as well as activation of drug removal mechanisms related to multidrug resistance.
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Affiliation(s)
- Dorota Matyszewska
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland.
| | - Ewa Nazaruk
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - Richard A Campbell
- Institut Laue-Langevin, 71 avenue des Martyrs, CS20156, 38042 Grenoble, France; Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, United Kingdom.
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Membrane interactions of antimicrobial peptide-loaded microgels. J Colloid Interface Sci 2020; 562:322-332. [DOI: 10.1016/j.jcis.2019.12.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/05/2019] [Accepted: 12/06/2019] [Indexed: 12/16/2022]
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22
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Clifton LA, Campbell RA, Sebastiani F, Campos-Terán J, Gonzalez-Martinez JF, Björklund S, Sotres J, Cárdenas M. Design and use of model membranes to study biomolecular interactions using complementary surface-sensitive techniques. Adv Colloid Interface Sci 2020; 277:102118. [PMID: 32044469 DOI: 10.1016/j.cis.2020.102118] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/24/2020] [Accepted: 01/29/2020] [Indexed: 01/07/2023]
Abstract
Cellular membranes are complex structures and simplified analogues in the form of model membranes or biomembranes are used as platforms to understand fundamental properties of the membrane itself as well as interactions with various biomolecules such as drugs, peptides and proteins. Model membranes at the air-liquid and solid-liquid interfaces can be studied using a range of complementary surface-sensitive techniques to give a detailed picture of both the structure and physicochemical properties of the membrane and its resulting interactions. In this review, we will present the main planar model membranes used in the field to date with a focus on monolayers at the air-liquid interface, supported lipid bilayers at the solid-liquid interface and advanced membrane models such as tethered and floating membranes. We will then briefly present the principles as well as the main type of information on molecular interactions at model membranes accessible using a Langmuir trough, quartz crystal microbalance with dissipation monitoring, ellipsometry, atomic force microscopy, Brewster angle microscopy, Infrared spectroscopy, and neutron and X-ray reflectometry. A consistent example for following biomolecular interactions at model membranes is used across many of the techniques in terms of the well-studied antimicrobial peptide Melittin. The overall objective is to establish an understanding of the information accessible from each technique, their respective advantages and limitations, and their complementarity.
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Affiliation(s)
- Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 OQX, United Kingdom
| | - Richard A Campbell
- Division of Pharmacy and Optometry, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Federica Sebastiani
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - José Campos-Terán
- Departamento de Procesos y Tecnología, Universidad Autónoma Metropolitana, Unidad Cuajimalpa, Av. Vasco de Quiroga 4871, Col. Santa Fe, Delegación Cuajimalpa de Morelos, 05348, Mexico; Lund Institute of advanced Neutron and X-ray Science, Lund University, Scheelevägen 19, 223 70 Lund, Sweden
| | - Juan F Gonzalez-Martinez
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - Sebastian Björklund
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - Javier Sotres
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden
| | - Marité Cárdenas
- Department of Biomedical Science and Biofilms - Research Center for Biointerfaces, Malmö University, 20506 Malmö, Sweden.
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23
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Orczyk M, Wojciechowski K, Brezesinski G. The influence of steroidal and triterpenoid saponins on monolayer models of the outer leaflets of human erythrocytes, E. coli and S. cerevisiae cell membranes. J Colloid Interface Sci 2019; 563:207-217. [PMID: 31874308 DOI: 10.1016/j.jcis.2019.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 01/15/2023]
Abstract
The present paper discusses the use of monolayers of lipid mixtures mimicking the composition of biological membranes of bacteria, erythrocyte and yeast in the context of the anti-bacterial, hemolytic and anti-fungal activity of saponins. Saponins are plant-produced glycosidic biosurfactants with either steroidal or triterpenoidal aglycone. In the present study we used digitonin as a representative steroidal saponin (extracted from Digitalis purpurea) and a mixture of triterpenoid saponins from Quillaja saponaria Molina. The effect of saponins was studied first on monolayers consisting of single lipids characteristic for the given type of biological membrane, and then - on model mixed lipid monolayers. Finally, the monolayers were formed from total lipid extracts of natural cell membranes (E. coli and S. cerevisiae) to verify the results obtained in the simplified models. The effect of saponins on monolayers was studied by a combination of surface pressure relaxation, infrared reflection - absorption spectroscopy (IRRAS) and fluorescence microscopy. In line with expectations, sterols (cholesterol and ergosterol) play a major role in the saponin-lipid interactions in monolayers, which may explain especially the hemolytic and antifungal properties of saponins. In contrast, bacterial membranes are devoid of sterols, although the presence of similar compounds may be responsible for their affinity to saponins. Nevertheless, the effect of saponins on bacterial models is less pronounced than for the erythrocyte or fungal ones.
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Affiliation(s)
- M Orczyk
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - K Wojciechowski
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland.
| | - G Brezesinski
- Max Planck Institute of Colloids and Interfaces, Science Park Potsdam-Golm, 14476 Potsdam, Germany
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24
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Gong H, Zhang J, Hu X, Li Z, Fa K, Liu H, Waigh TA, McBain A, Lu JR. Hydrophobic Control of the Bioactivity and Cytotoxicity of de Novo-Designed Antimicrobial Peptides. ACS APPLIED MATERIALS & INTERFACES 2019; 11:34609-34620. [PMID: 31448889 DOI: 10.1021/acsami.9b10028] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Antimicrobial peptides (AMPs) can target bacterial membranes and kill bacteria through membrane structural damage and cytoplasmic leakage. A group of surfactant-like cationic AMPs was developed from substitutions to selective amino acids in the general formula of G(IIKK)3I-NH2, (called G3, a de novo AMP), to explore the correlation between AMP hydrophobicity and bioactivity. A threshold surface pressure over 12 mN/m was required to cause measurable antimicrobial activity and this corresponded to a critical AMP concentration. Greater surface activity exhibited stronger antimicrobial activity but had the drawback of worsening hemolytic activity. Small unilamellar vesicles (SUVs) with specific lipid compositions were used to model bacterial and host mammalian cell membranes by mimicking the main structural determinants of the charge and composition. Leakage from the SUVs of encapsulated carboxyfluorescein measured by fluorescence spectroscopy indicated a negative correlation between hydrophobicity and model membrane selectivity, consistent with measurements of the zeta potential that demonstrated the extent of AMP binding onto model SUV lipid bilayers. Experiments with model lipid membranes thus explained the trend of minimum inhibitory concentrations and selectivity measured from real cell systems and demonstrated the dominant influence of hydrophobicity. This work provides useful guidance for the improvement of the potency of AMPs via structural design, whilst taking due consideration of cytotoxicity.
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Chang H, Gnanasekaran K, Gianneschi NC, Geiger FM. Bacterial Model Membranes Deform (resp. Persist) upon Ni2+ Binding to Inner Core (resp. O-Antigen) of Lipopolysaccharides. J Phys Chem B 2019; 123:4258-4270. [DOI: 10.1021/acs.jpcb.9b02762] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- HanByul Chang
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60660, United States
| | - Karthikeyan Gnanasekaran
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60660, United States
| | - Nathan C. Gianneschi
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60660, United States
| | - Franz M. Geiger
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60660, United States
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26
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Ciumac D, Gong H, Hu X, Lu JR. Membrane targeting cationic antimicrobial peptides. J Colloid Interface Sci 2019; 537:163-185. [DOI: 10.1016/j.jcis.2018.10.103] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/29/2018] [Accepted: 10/30/2018] [Indexed: 01/13/2023]
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27
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Campbell RA, Saaka Y, Shao Y, Gerelli Y, Cubitt R, Nazaruk E, Matyszewska D, Lawrence MJ. Structure of surfactant and phospholipid monolayers at the air/water interface modeled from neutron reflectivity data. J Colloid Interface Sci 2018; 531:98-108. [DOI: 10.1016/j.jcis.2018.07.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/06/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
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28
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Campbell RA. Recent advances in resolving kinetic and dynamic processes at the air/water interface using specular neutron reflectometry. Curr Opin Colloid Interface Sci 2018. [DOI: 10.1016/j.cocis.2018.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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29
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Matyszewska D, Moczulska S. Effect of pH on the interactions of doxorubicin with charged lipid monolayers containing 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine - An important component of cancer cell membranes. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.05.119] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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30
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Link KA, Hsieh CY, Tuladhar A, Chase Z, Wang Z, Wang H, Walker RA. Vibrational studies of saccharide-induced lipid film reorganization at aqueous/air interfaces. Chem Phys 2018. [DOI: 10.1016/j.chemphys.2018.02.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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31
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de Souza KD, Perez KR, Durán N, Justo GZ, Caseli L. Interaction of violacein in models for cellular membranes: Regulation of the interaction by the lipid composition at the air-water interface. Colloids Surf B Biointerfaces 2017; 160:247-253. [DOI: 10.1016/j.colsurfb.2017.09.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 09/04/2017] [Accepted: 09/10/2017] [Indexed: 11/16/2022]
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Ciumac D, Campbell RA, Clifton LA, Xu H, Fragneto G, Lu JR. Influence of Acyl Chain Saturation on the Membrane-Binding Activity of a Short Antimicrobial Peptide. ACS OMEGA 2017; 2:7482-7492. [PMID: 30023555 PMCID: PMC6044940 DOI: 10.1021/acsomega.7b01270] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 10/12/2017] [Indexed: 05/03/2023]
Abstract
Different bacterial types and their living environments can lead to different saturations in the chains of their membrane lipids. Such structural differences may influence the efficacy of antibiotics that target bacterial membranes. In this work, the effects of acyl chain saturation on the binding of an antimicrobial peptide G4 have been examined as a function of the packing density of lipid monolayers by combining external reflection Fourier transform infrared (ER-FTIR) spectroscopy and neutron reflection (NR) measurements. Langmuir monolayers were formed from 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG), respectively, with the initial surface pressures controlled at 8 and 28 mN/m. A reduction in the order of the acyl chains associated with the increase in the layer thickness upon G4 binding was revealed from ER-FTIR spectroscopy, with peptide binding reaching equilibration faster in POPG than in DPPG monolayers. Whereas the dynamic DPPG-binding process displayed a steady increase in the amide I band area, the POPG-binding process showed little change in the amide area after the initial period. The peptide amide I area from ER-FTIR spectroscopy could be linearly correlated with the adsorbed G4 amount from NR, irrespective of time, initial pressure, or chain saturation, with clearly more peptide incorporated into the DPPG monolayer. Furthermore, NR revealed that although the peptide was associated with both POPG and DPPG lipid monolayers, it was more extensively distributed in the latter, showing that acyl chain saturation clearly promoted peptide binding and structural disruption.
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Affiliation(s)
- Daniela Ciumac
- Biological
Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, U.K.
| | - Richard A. Campbell
- Institute
of Laue Langevin, 71
Avenue des Martyrs, CS-20156, 38042 Grenoble, France
| | | | - Hai Xu
- Centre
for Bioengineering and Biotechnology, China
University of Petroleum, Qingdao 266580, China
| | - Giovanna Fragneto
- Institute
of Laue Langevin, 71
Avenue des Martyrs, CS-20156, 38042 Grenoble, France
| | - Jian R. Lu
- Biological
Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Schuster Building, Manchester M13 9PL, U.K.
- E-mail: . Phone: +44 161 2003926 (J.R.L.)
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Almahboub SA, Narancic T, Devocelle M, Kenny ST, Palmer-Brown W, Murphy C, Nikodinovic-Runic J, O'Connor KE. Biosynthesis of 2-aminooctanoic acid and its use to terminally modify a lactoferricin B peptide derivative for improved antimicrobial activity. Appl Microbiol Biotechnol 2017; 102:789-799. [PMID: 29177937 DOI: 10.1007/s00253-017-8655-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/15/2017] [Accepted: 11/15/2017] [Indexed: 12/11/2022]
Abstract
Terminal modification of peptides is frequently used to improve their hydrophobicity. While N-terminal modification with fatty acids (lipidation) has been reported previously, C-terminal lipidation is limited as it requires the use of linkers. Here we report the use of a biocatalyst for the production of an unnatural fatty amino acid, (S)-2-aminooctanoic acid (2-AOA) with enantiomeric excess > 98% ee and the subsequent use of 2-AOA to modify and improve the activity of an antimicrobial peptide. A transaminase originating from Chromobacterium violaceum was employed with a conversion efficiency 52-80% depending on the ratio of amino group donor to acceptor. 2-AOA is a fatty acid with amino functionality, which allowed direct C- and N-terminal conjugation respectively to an antimicrobial peptide (AMP) derived from lactoferricin B. The antibacterial activity of the modified peptides was improved by up to 16-fold. Furthermore, minimal inhibitory concentrations (MIC) of C-terminally modified peptide were always lower than N-terminally conjugated peptides. The C-terminally modified peptide exhibited MIC values of 25 μg/ml for Escherichia coli, 50 μg/ml for Bacillus subtilis, 100 μg/ml for Salmonella typhimurium, 200 μg/ml for Pseudomonas aeruginosa and 400 μg/ml for Staphylococcus aureus. The C-terminally modified peptide was the only peptide tested that showed complete inhibition of growth of S. aureus.
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Affiliation(s)
- Sarah A Almahboub
- UCD Earth Institute and School of Biomolecular and Biomedical Science, O'Brien Centre for Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Tanja Narancic
- UCD Earth Institute and School of Biomolecular and Biomedical Science, O'Brien Centre for Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Marc Devocelle
- Centre for Synthesis and Chemical Biology, Department of Pharmaceutical & Medicinal Chemistry, Royal College of Surgeons in Ireland, 123 St Stephens Green, Dublin 2, Ireland
| | - Shane T Kenny
- Bioplastech Ltd., Nova UCD, Belfield Innovation Park, University College Dublin, Belfield, Dublin 4, Ireland
| | - William Palmer-Brown
- UCD Earth Institute and School of Biomolecular and Biomedical Science, O'Brien Centre for Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Cormac Murphy
- UCD Earth Institute and School of Biomolecular and Biomedical Science, O'Brien Centre for Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Jasmina Nikodinovic-Runic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, Serbia
| | - Kevin E O'Connor
- UCD Earth Institute and School of Biomolecular and Biomedical Science, O'Brien Centre for Science, University College Dublin, Belfield, Dublin 4, Ireland. .,BEACON - Bioeconomy Research Centre, University College Dublin, Belfield, Dublin 4, Ireland.
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Braun L, Uhlig M, von Klitzing R, Campbell RA. Polymers and surfactants at fluid interfaces studied with specular neutron reflectometry. Adv Colloid Interface Sci 2017; 247:130-148. [PMID: 28822539 DOI: 10.1016/j.cis.2017.07.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 07/08/2017] [Indexed: 01/18/2023]
Abstract
This review addresses the advances made with specular neutron reflectometry in studies of aqueous mixtures of polymers and surfactants at fluid interfaces during the last decade (or so). The increase in neutron flux due to improvements in instrumentation has led to routine measurements at the air/water interface that are faster and involve samples with lower isotopic contrast than in previous experiments. One can now resolve the surface excess of a single deuterated component on the second time scale and the composition of a mixture on the minute time scale, and information about adsorption processes and dynamic rheology can also be accessed. Research areas addressed include the types of formed equilibrium surface structures, the link to foam film stability and the range of non-equilibrium effects that dominate the behavior of oppositely charged polyelectrolyte/surfactant mixtures, macroscopic film formation in like-charged polymer/surfactant mixtures, and the properties of mixtures of bio-polymers with surfactants and lipids.
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