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Fu L, Li X, Zhang S, Dong Y, Fang W, Gao L. Polymyxins induce lipid scrambling and disrupt the homeostasis of Gram-negative bacteria membrane. Biophys J 2022; 121:3486-3498. [PMID: 35964158 PMCID: PMC9515121 DOI: 10.1016/j.bpj.2022.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/01/2022] [Accepted: 08/10/2022] [Indexed: 11/30/2022] Open
Abstract
Polymyxins are increasingly used as the last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, efforts to address the resistance in superbugs are compromised by a poor understanding of the bactericidal modes because high-resolution detection of the cell structure is still lacking. By performing molecular dynamics simulations at a coarse-grained level, here we show that polymyxin B (PmB) disrupts Gram-negative bacterial membranes by altering lipid homeostasis and asymmetry. We found that the binding of PmBs onto the asymmetric outer membrane (OM) loosens the packing of lipopolysaccharides (LPS) and induces unbalanced bending torque between the inner and outer leaflets, which in turn triggers phospholipids to flip from the inner leaflet to the outer leaflet to compensate for the stress deformation. Meanwhile, some LPSs may be detained on the inner membrane (IM). Then, the lipid-scrambled OM undergoes phase separation. Defects are created at the boundaries between LPS-rich domains and phospholipid-rich domains, which consequently facilitate the uptake of PmB across the OM. Finally, PmBs target LPSs detained on the IM and similarly perturb the IM. This lipid Scramble, membrane phase Separation, and peptide Translocation model depicts a novel mechanism by which polymyxins kill bacteria and sheds light on developing a new generation of polymyxins or antibiotic adjuvants with improved killing activities and higher therapeutic indices.
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Affiliation(s)
- Lei Fu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Xiangyuan Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Shan Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Yi Dong
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Lianghui Gao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
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Interaction of Lipopolysaccharide-Spiked Blood with Anti-Fouling Polymyxin B-Modified Glass. MATERIALS 2022; 15:ma15041551. [PMID: 35208091 PMCID: PMC8876862 DOI: 10.3390/ma15041551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 11/20/2022]
Abstract
Bacterial endotoxin, also known as lipopolysaccharide (LPS), plays a major role in the initiation of sepsis, a severe inflammatory condition. Removal of the toxin from blood is one accepted method of patient treatment. Polymyxin B (PMB)-modified columns have been employed successfully for this purpose via extra-corporeal blood-flow systems that incorporate a cartridge for toxin removal. Herein we demonstrate that PMB-modified glass beads are able to reduce the presence of LPS competitively with the equivalent fiber column used in a commercial cartridge. Analysis by gas chromatography-mass spectrometry and ELISA of released fatty acids from the toxin indicates that PMB does not physically capture or significantly remove LPS from the blood samples. In reality, interaction between the surface-bound PMB and the toxin may lead to disaggregation or monomerization of LPS aggregates. As aggregates are the bioactive form of LPS, it is possible that the monomerization of these entities may be the mechanism by which their toxicity is reduced. Moreover, this work indicates that LPS monomers are stabilized subsequent to disaggregation induced by PMB.
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Lin L, Chi J, Yan Y, Luo R, Feng X, Zheng Y, Xian D, Li X, Quan G, Liu D, Wu C, Lu C, Pan X. Membrane-disruptive peptides/peptidomimetics-based therapeutics: Promising systems to combat bacteria and cancer in the drug-resistant era. Acta Pharm Sin B 2021; 11:2609-2644. [PMID: 34589385 PMCID: PMC8463292 DOI: 10.1016/j.apsb.2021.07.014] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 02/05/2023] Open
Abstract
Membrane-disruptive peptides/peptidomimetics (MDPs) are antimicrobials or anticarcinogens that present a general killing mechanism through the physical disruption of cell membranes, in contrast to conventional chemotherapeutic drugs, which act on precise targets such as DNA or specific enzymes. Owing to their rapid action, broad-spectrum activity, and mechanisms of action that potentially hinder the development of resistance, MDPs have been increasingly considered as future therapeutics in the drug-resistant era. Recently, growing experimental evidence has demonstrated that MDPs can also be utilized as adjuvants to enhance the therapeutic effects of other agents. In this review, we evaluate the literature around the broad-spectrum antimicrobial properties and anticancer activity of MDPs, and summarize the current development and mechanisms of MDPs alone or in combination with other agents. Notably, this review highlights recent advances in the design of various MDP-based drug delivery systems that can improve the therapeutic effect of MDPs, minimize side effects, and promote the co-delivery of multiple chemotherapeutics, for more efficient antimicrobial and anticancer therapy.
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Affiliation(s)
- Liming Lin
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Jiaying Chi
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Yilang Yan
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Rui Luo
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Xiaoqian Feng
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Yuwei Zheng
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Dongyi Xian
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Xin Li
- The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China
| | - Guilan Quan
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Daojun Liu
- Shantou University Medical College, Shantou 515041, China
| | - Chuanbin Wu
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Chao Lu
- College of Pharmacy, Jinan University, Guangzhou 511443, China
| | - Xin Pan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
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Removal of Circulating Neutrophil Extracellular Trap Components With an Immobilized Polymyxin B Filter: A Preliminary Study. Shock 2021; 54:44-49. [PMID: 31764624 DOI: 10.1097/shk.0000000000001476] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Components of neutrophil extracellular traps (NETs) are released into the circulation by neutrophils and contribute to microcirculatory disturbance in sepsis. Removing NET components (DNA, histones, and proteases) from the circulation could be a new strategy for counteracting NET-dependent tissue damage. We evaluated the effect of hemoperfusion with a polymyxin B (PMX) cartridge, which was originally developed for treating gram-negative infection, on circulating NET components in patients with septic shock, as well as the effect on phorbol myristate acetate (PMA)-stimulated neutrophils obtained from healthy volunteers. Ex vivo closed loop hemoperfusion was performed through PMX filters in a laboratory circuit. Whole blood from healthy volunteers (incubated with or without PMA) or from septic shock patients was perfused through the circuit. For in vivo experiment blood samples were collected before and immediately after hemoperfusion with PMX to measure the plasma levels of cell-free NETs. The level of cell-free NETs was assessed by measuring myeloperoxidase-associated DNA (MPO-DNA), neutrophil elastase-associated DNA (NE-DNA), and cell-free DNA (cf-DNA). Plasma levels of MPO-DNA, NE-DNA, and cf-DNA were significantly increased after 2 h of PMA stimulation. When the circuit was perfused with blood from septic shock patients or PMA-stimulated neutrophils from healthy volunteers, circulating levels of MPO-DNA, NE-DNA, and cf-DNA were significantly reduced after 1 and 2 h of perfusion with a PMX filter compared with perfusion without a PMX filter. In 10 patients with sepsis, direct hemoperfusion through filters with immobilized PMX significantly reduced plasma levels of MPO-DNA and NE-DNA. These ex vivo and in vivo findings demonstrated that hemoperfusion with PMX removes circulating NET components. Selective removal of circulating NET components from the blood could be effective for prevention/treatment of NET-related inappropriate inflammation and thrombogenesis in patients with sepsis.
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Yang K, Peng Y, Wang L, Ren L. Polymyxin B engineered polystyrene-divinylbenzene microspheres for the adsorption of bilirubin and endotoxin. RSC Adv 2021; 11:39978-39984. [PMID: 35494100 PMCID: PMC9044794 DOI: 10.1039/d1ra06684f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/30/2021] [Indexed: 11/21/2022] Open
Abstract
Hemoperfusion is an important strategy for liver disease treatment. Polystyrene-divinylbenzene (PS-DVB) microspheres are widely applied as absorbents in hemoperfusion to efficiently remove the important toxin bilirubin. However, as another common toxin, endotoxin will remain during this process and cause endotoxemia. Therefore, simultaneous removal of both bilirubin and endotoxin is highly desirable. In the present study, we engineered PS-DVB microspheres with polymyxin B sulfate (PMB) to meet this goal. After modification, the novel PMB-engineered (P-PMB) microspheres displayed excellent biocompatibility and hemocompatibility. Notably, compared to PS-DVB microspheres, P-PMB microspheres exhibited markedly stronger detoxification of both bilirubin and endotoxin, increasing by 17.03% and 42.57%, respectively. Overall, we believe that the novel P-PMB microspheres have considerable potential for liver disease treatment in clinical practice. A new adsorbent for hemoperfusion was successfully prepared by grafting polymyxin B (PMB) on the surface of polystyrene divinylbenzene (PS-DVB) microspheres. It showed good biocompatibility and could adsorb both bilirubin and endotoxin.![]()
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Affiliation(s)
- Kangle Yang
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510006, China
- Key Laboratory of Biomedical Engineering of Guangdong Province, South China University of Technology, Guangzhou 510006, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
- Innovation Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
| | - Yaotian Peng
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510006, China
- National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
- Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, China
| | - Lin Wang
- National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
- Key Laboratory of Biomedical Materials and Engineering of the Ministry of Education, South China University of Technology, Guangzhou 510006, China
| | - Li Ren
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510006, China
- National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
- Key Laboratory of Biomedical Engineering of Guangdong Province, South China University of Technology, Guangzhou 510006, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou 510005, China
- Innovation Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou 510006, China
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Fu L, Wan M, Zhang S, Gao L, Fang W. Polymyxin B Loosens Lipopolysaccharide Bilayer but Stiffens Phospholipid Bilayer. Biophys J 2019; 118:138-150. [PMID: 31812355 DOI: 10.1016/j.bpj.2019.11.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/31/2019] [Accepted: 11/08/2019] [Indexed: 12/17/2022] Open
Abstract
Multidrug-resistant Gram-negative bacteria have increased the prevalence of a variety of serious diseases in modern times. Polymyxins are used as the last-line therapeutic options for the treatment of infections. However, the mechanism of action of polymyxins remains in dispute. In this work, we used a coarse-grained molecular dynamics simulation to investigate the mechanism of the cationic antimicrobial peptide polymyxin B (PmB) interacting with both the inner and outer membrane models of bacteria. Our results show that the binding of PmB disturbs the outer membrane by displacing the counterions, decreasing the orientation order of the lipopolysaccharide tail, and creating more lipopolysaccharide packing defects. Upon binding onto the inner membrane, in contrast to the traditional killing mechanism that antimicrobial peptides usually use to induce holes in the membrane, PmBs do not permeabilize the inner membrane but stiffen it by filling up the lipid packing defect, increasing the lipid tail order and the membrane bending rigidity as well as restricting the lipid diffusion. PmBs also mediate intermembrane contact and adhesion. These joint effects suggest that PmBs deprive the biological activity of Gram-negative bacteria by sterilizing the cell.
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Affiliation(s)
- Lei Fu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Mingwei Wan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Shan Zhang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
| | - Lianghui Gao
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China.
| | - Weihai Fang
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing, China
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Malard B, Lambert C, Kellum JA. In vitro comparison of the adsorption of inflammatory mediators by blood purification devices. Intensive Care Med Exp 2018; 6:12. [PMID: 29728790 PMCID: PMC5935601 DOI: 10.1186/s40635-018-0177-2] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 04/13/2018] [Indexed: 01/17/2023] Open
Abstract
Background Septic shock, a leading cause of acute kidney injury, induces release of pro-/anti-inflammatory mediators, leading to increased mortality and poor renal recovery. This is the first in vitro study directly comparing three single-use blood purification devices in terms of removing sepsis-associated mediators and endotoxins. Methods In vitro hemoperfusion was performed using oXiris®, CytoSorb®, and Toraymyxin®. Heparinized human plasma from healthy volunteers was pre-incubated with pathologic quantities of inflammatory mediators and filtered in a closed-loop circulation model for 2 h. For each device, the removal of 27 inflammatory mediators was measured over time. Endotoxin removal mediated by oXiris and Toraymyxin was assessed using hemoperfusion over 6 h. Results Endotoxin (lipopolysaccharide) removal was most rapid with Toraymyxin; mean adsorptive clearance over the first 30 min was ~ 20 ml/min vs ~ 8 ml/min with oXiris (p < 0.05). There was minimal endotoxin removal with CytoSorb (1 ml/min). At 120 min, there was no significant difference between the endotoxin removal rates using oXiris (mean ± standard deviation, 68.0 ± 4.4%) and Toraymyxin (83.4 ± 3.8%); both were significantly higher vs CytoSorb (− 6.3 ± 4.9%; p < 0.05). Total removal with oXiris was 6.9 μg vs 9.7 μg for Toraymyxin, where the total lipopolysaccharide quantity introduced was approximately 15.8 μg. Removal rates of pro-/anti-inflammatory cytokines and other inflammatory mediators were similar between oXiris and CytoSorb and were higher with CytoSorb and oXiris vs Toraymyxin. Granulocyte colony-stimulating factor was only effectively adsorbed by CytoSorb (99.4%). Differences were detected between the adsorption mechanism of the devices; binding to oXiris was mainly ionic, while CytoSorb was hydrophobic. No specific protein adsorption was found qualitatively with Toraymyxin. Conclusions Adsorption rate kinetics varied for individual inflammatory mediators using the three blood purification devices. Mechanisms of adsorption differed between the devices. oXiris was the only device tested that showed both endotoxin and cytokine removal. oXiris showed similar endotoxin adsorption to Toraymyxin and similar adsorption to CytoSorb for the removal of other inflammatory mediators. Differences in device removal capacities could enable treatment to be more tailored to patients. Electronic supplementary material The online version of this article (10.1186/s40635-018-0177-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Benjamin Malard
- R&D Department, Gambro Industries, 7 avenue Lionel Terray, 69330, Meyzieu, France.
| | - Corine Lambert
- R&D Department, Gambro Industries, 7 avenue Lionel Terray, 69330, Meyzieu, France
| | - John A Kellum
- Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh, 604 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA, 15261, USA
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Abstract
Conflicting results have been reported on the influence of Polymyxin-B hemoperfusion treatment on systemic inflammation markers. The aim of the study was to assess in a randomized control trial the influence on plasma cytokine concentrations of Polymyxin-B hemoperfusion in septic shock due to peritonitis. A panel of 10 pro- or anti-inflammatory cytokines was measured in 213 patients with peritonitis-induced septic shock enrolled in the randomized trial ABDOMIX testing the impact of 2 Polymyxin-B hemoperfusion sessions with standard treatment. Gram-negative bacteria were identified in 69% of patients. In the overall population, baseline plasma cytokine concentrations were not different between the two groups. Circulating tumor necrosis factor-α, interleukin (IL)-1β, IL-10, IL-6, and IL-1RA decreased significantly over time in both groups (P <0.0001 for all in controls, and P = 0.0002, 0.003, and <0.0001 in patients treated with Polymyxin-B hemoperfusion). IL-17A decreased significantly in patients treated with Polymyxin B hemoperfusion (P = 0.045) but not in controls. At the end of the second Polymyxin-B hemoperfusion session or at corresponding time in controls, plasma levels of cytokines did not differ between the two groups. Similar results were found in the subgroup of patients with gram-negative peritonitis who completed two Polymyxin-B hemoperfusion sessions. These results do not support a significant influence of Polymyxin-B hemoperfusion on circulating cytokines assessed except for IL-17A which clinical significance remains to be elucidated.
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Zdorovenko EL, Kadykova AA, Shashkov AS, Varbanets LD, Bulyhina TV, Knirel YA. Lipopolysaccharide of Pantoea agglomerans 7969: Chemical identification, function and biological activity. Carbohydr Polym 2017; 165:351-358. [PMID: 28363559 DOI: 10.1016/j.carbpol.2017.02.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/14/2017] [Accepted: 02/14/2017] [Indexed: 10/20/2022]
Abstract
Lipopolysaccharide (LPS) of Pantoea agglomerans 7969 isolated from apple tree was purified and characterized chemically by sugar and fatty acid analysis. Lipid A was analysed by negative-ion mode ESI MS and found to consist mainly of hexa- and tetra-acyl species typical of E. coli lipid A. The O-specific polysaccharide of the LPS was studied by sugar analysis, Smith degradation, and one- and two-dimensional 1H and 13C NMR spectroscopy. The polysaccharide is built up of linear tetrasaccharide repeating units, and about ∼25% repeats contain glycerol 1-phosphate on the GlcNAc residue: →3)-α-l-Rha p-(1→6)-α-d-Man p-(1→3)-α-d-Fuc p-(1→3)-β-d-Glc pNAc-(1→∼25% Gro-1-P-(O→6)⌋ The LPS showed low levels of toxic and pyrogenic activities and reduced the average adhesion and the index of adhesiveness.
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Affiliation(s)
- Evelina L Zdorovenko
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia.
| | - Alexandra A Kadykova
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia
| | - Alexander S Shashkov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia
| | - Ludmila D Varbanets
- D.K. Zabolotny Insitute of Microbiology and Virology of the National Academy of Sciences, 154 Zabolotnoho Str., 03143 Kiev, Ukraine
| | - Tetiana V Bulyhina
- D.K. Zabolotny Insitute of Microbiology and Virology of the National Academy of Sciences, 154 Zabolotnoho Str., 03143 Kiev, Ukraine
| | - Yuriy A Knirel
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 47, 119991 Moscow, Russia
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Donnell ML, Lyon AJ, Mormile MR, Barua S. Endotoxin hitchhiking on polymer nanoparticles. NANOTECHNOLOGY 2016; 27:285601. [PMID: 27254407 DOI: 10.1088/0957-4484/27/28/285601] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The control of microbial infections is critical for the preparation of biological media including water to prevent lethal septic shock. Sepsis is one of the leading causes of death in the United States. More than half a million patients suffer from sepsis every year. Both gram-positive and gram-negative bacteria are responsible for septic infection by the most common organisms i.e., Escherichia coli and Pseuodomonas aeruginosa. The bacterial cell membrane releases negatively charged endotoxins upon death and enzymatic destruction, which stimulate antigenic response in humans to gram-negative infections. Several methods including distillation, ethylene oxide treatment, filtration and irradiation have been employed to remove endotoxins from contaminated samples, however, the reduction efficiency remains low, and presents a challenge. Polymer nanoparticles can be used to overcome the current inability to effectively sequester endotoxins from water. This process is termed endotoxin hitchhiking. The binding of endotoxin on polymer nanoparticles via electrostatic and hydrophobic interactions offers efficient removal from water. However, the effect of polymer nanoparticles and its surface areas has not been investigated for removal of endotoxins. Poly(ε-caprolactone) (PCL) polymer was tested for its ability to effectively bind and remove endotoxins from water. By employing a simple one-step phase separation technique, we were able to synthesize PCL nanoparticles of 398.3 ± 95.13 nm size and a polydispersity index of 0.2. PCL nanoparticles showed ∼78.8% endotoxin removal efficiency, the equivalent of 3.9 × 10(5) endotoxin units (EU) per ml. This is 8.34-fold more effective than that reported for commercially available membranes. Transmission electron microscopic images confirmed binding of multiple endotoxins to the nanoparticle surface. The concept of using nanoparticles may be applicable not only to eliminate gram-negative bacteria, but also for any gram-positive bacteria, fungi and parasites.
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Affiliation(s)
- Mason L Donnell
- Department of Chemical and Biochemical Engineering Missouri University of Science and Technology, Rolla, MO 65409, USA
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Mitaka C, Masuda T, Kido K, Uchida T, Abe S, Miyasho T, Tomita M, Inada E. Polymyxin B hemoperfusion prevents acute kidney injury in sepsis model. J Surg Res 2015; 201:59-68. [PMID: 26850185 DOI: 10.1016/j.jss.2015.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Revised: 10/01/2015] [Accepted: 10/08/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND Direct hemoperfusion with a polymyxin B-immobilized column (PMX-DHP) adsorbs endotoxin and has been used for the treatment of septic shock. Yet, the mechanisms by which PMX-DHP acts on acute kidney injury are only partially understood. MATERIALS AND METHODS Rats were anesthetized, tracheostomized, and placed on mechanical ventilation. The animals were randomized to three groups: a cecal ligation and puncture (CLP) + dummy-DHP group (n = 10), a CLP + PMX-DHP group (n = 10), and a sham group (n = 4). Four hours after CLP, a dummy-DHP or PMX-DHP was performed for 1 h. The heart rate, mean arterial pressure, arterial blood gases, and plasma concentrations of creatinine, lactate, potassium, interleukin (IL)-6, and IL-10 were measured at 0 h and 8 h. Eight hours after CLP, the kidney was harvested, and histopathologic examination was performed. The expressions of cleaved poly (ADP-ribose) polymerase (PARP) and nuclear factor (NF)-κB p65 were examined by immunohistochemistry. A terminal deoxynucleotide transferase dUTP nick-end labeling assay was performed to detect apoptotic nuclei in kidney sections. RESULTS PMX-DHP maintained hemodynamics and the acid-base balance and significantly (P < 0.05) decreased the plasma concentrations of lactate, creatinine, potassium, IL-6, and IL-10 compared with dummy-DHP. PMX-DHP significantly (P < 0.001) attenuated the expressions of cleaved PARP and NF-κB p65 in renal tubular cells and renal tubular cell apoptosis compared with dummy-DHP. CONCLUSIONS These findings suggest that PMX-DHP may protect against acute kidney injury not only by inhibiting the NF-κB signaling pathway but also by preventing renal tubular cell apoptosis.
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Affiliation(s)
- Chieko Mitaka
- Department of Anesthesiology, Juntendo University Hospital, Tokyo, Japan; Department of Anesthesiology, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan.
| | - Takahiro Masuda
- Intensive Care Unit, Tokyo Medical and Dental University Hospital of Medicine, Tokyo, Japan
| | - Koji Kido
- Department of Anesthesiology, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan
| | - Tokujiro Uchida
- Department of Anesthesiology, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan
| | - Shinya Abe
- Department of Comprehensive Pathology, Tokyo Medical and Dental University Graduate School of Medical and Dental Sciences, Tokyo, Japan
| | - Taku Miyasho
- Laboratory of Animal Biological Responses, Department of Veterinary Science School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan
| | - Makoto Tomita
- Clinical Research Center, Tokyo Medical and Dental University Hospital of Medicine, Tokyo, Japan
| | - Eiichi Inada
- Department of Anesthesiology, Juntendo University Hospital, Tokyo, Japan
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12
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Carmona-Ribeiro AM, de Melo Carrasco LD. Novel formulations for antimicrobial peptides. Int J Mol Sci 2014; 15:18040-83. [PMID: 25302615 PMCID: PMC4227203 DOI: 10.3390/ijms151018040] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 08/30/2014] [Accepted: 09/16/2014] [Indexed: 12/22/2022] Open
Abstract
Peptides in general hold much promise as a major ingredient in novel supramolecular assemblies. They may become essential in vaccine design, antimicrobial chemotherapy, cancer immunotherapy, food preservation, organs transplants, design of novel materials for dentistry, formulations against diabetes and other important strategical applications. This review discusses how novel formulations may improve the therapeutic index of antimicrobial peptides by protecting their activity and improving their bioavailability. The diversity of novel formulations using lipids, liposomes, nanoparticles, polymers, micelles, etc., within the limits of nanotechnology may also provide novel applications going beyond antimicrobial chemotherapy.
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Affiliation(s)
- Ana Maria Carmona-Ribeiro
- Biocolloids Laboratory, Instituto de Química, Universidade de São Paulo, Av. Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil.
| | - Letícia Dias de Melo Carrasco
- Biocolloids Laboratory, Instituto de Química, Universidade de São Paulo, Av. Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil.
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13
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Ronco C, Klein DJ. Polymyxin B hemoperfusion: a mechanistic perspective. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2014; 18:309. [PMID: 25043934 PMCID: PMC4077196 DOI: 10.1186/cc13912] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Direct hemoperfusion therapy with polymyxin B immobilized fiber cartridge (PMX-DHP)
is an established strategy in the treatment of septic shock in Japan and parts of
Western Europe. PMX-DHP is currently the subject of a pivotal North American
randomized controlled trial (EUPHRATES) in patients with septic shock and confirmed
endotoxemia, as measured by the endotoxin activity assay. The major mechanism of
action of this therapy is the removal of circulating endotoxin. High affinity binding
of circulating endotoxin by the PMX-DHP column may decrease circulating endotoxin
levels by up to 90% after two standard treatments. Basic research has shown
reductions in circulating cytokine levels and in renal tubular apoptosis. Clinical
research has shown that PMX-DHP therapy results in hemodynamic improvements,
improvements in oxygenation, renal function, and reductions in mortality. Further
research is needed to further define additional patient populations with endotoxemia
that may benefit from PMX-DHP therapy as well as to further elucidate dosing, timing,
and additional information on mechanisms of action. This review will present the
mechanistic rationale for this targeted strategy of endotoxin removal using PMX-DHP
in endotoxemic septic patients, highlighting both the specific effects of the therapy
and the evidence accumulated so far of clinical improvement following this therapy in
terms of recovery of organ function.
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14
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Immunomodulation in sepsis: the role of endotoxin removal by polymyxin B-immobilized cartridge. Mediators Inflamm 2013; 2013:507539. [PMID: 24249974 PMCID: PMC3819752 DOI: 10.1155/2013/507539] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 09/16/2013] [Indexed: 12/14/2022] Open
Abstract
Severe sepsis results in high morbidity and mortality. Immunomodulation strategies could be an adjunctive therapy to treat sepsis. Endotoxin is a component of gram-negative bacteria and plays an important role in the pathogenesis of septic shock when it is recognized by immune cells. Removal of endotoxin could be an effective adjunctive approach to the management of sepsis. Devices to adsorb endotoxin or inflammatory cytokines have been designed as a strategy to treat severe sepsis, especially sepsis caused by gram-negative bacteria. Polymyxin B-immobilized cartridge has been successfully used to treat patients with sepsis of abdominal origin. Although this cartridge was conceived to adsorb endotoxin, several other immunological mechanisms have been elucidated, and this device has also yielded promising results in patients with nonseptic respiratory failure. In this paper, we summarize the immune modulation actions of Polymyxin B-immobilized cartridge to explore its potential usefulness beyond endotoxin elimination.
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15
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Structural analysis and ion translocation mechanisms of the muscle-type acetylcholine receptor channel. J Appl Biomater Funct Mater 2013; 11:e53-60. [PMID: 23728540 DOI: 10.5301/jabfm.5000148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2012] [Indexed: 12/13/2022] Open
Abstract
PURPOSE The aim of this work is to analyze the conformational changes in the acetylcholine receptor caused by channel opening and to investigate the electrostatic profile during ion translocation through the channel. METHODS A computational model of the human muscle-type acetylcholine receptor (AChR) was built and used to analyze channel structure and its interactions with different ions. Using the Torpedo AChR crystal structure as a homologous template, the 3D structure of the human muscle-type AChR was reconstructed. RESULTS This first model is optimized and an open structure of the channel is generated using Normal Mode Analysis in order to assess morphologic and energetic differences between open and closed structures. In addition, the issue of ion translocation is investigated in further detail. Results elucidate different aspects of the channel: channel gate structure, channel interactions with translocating ions, differences between muscle-type AChR and previous neuronal-type AChR models. CONCLUSIONS The model constructed here is ideal for further computational studies on muscle-type AChR and its pathologic mutations.
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Computational evaluation of the thrombogenic potential of a hollow-fiber oxygenator with integrated heat exchanger during extracorporeal circulation. Biomech Model Mechanobiol 2012; 13:349-61. [PMID: 23053595 DOI: 10.1007/s10237-012-0445-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 09/21/2012] [Indexed: 10/27/2022]
Abstract
The onset of thromboembolic phenomena in blood oxygenators, even in the presence of adequate anticoagulant strategies, is a relevant concern during extracorporeal circulation (ECC). For this reason, the evaluation of the thrombogenic potential associated with extracorporeal membrane oxygenators should play a critical role into the preclinical design process of these devices. This study extends the use of computational fluid dynamics simulations to guide the hemodynamic design optimization of oxygenators and evaluate their thrombogenic potential during ECC. The computational analysis accounted for both macro- (i.e., vortex formation) and micro-scale (i.e., flow-induced platelet activation) phenomena affecting the performances of a hollow-fiber membrane oxygenator with integrated heat exchanger. A multiscale Lagrangian approach was adopted to infer the trajectory and loading history experienced by platelet-like particles in the entire device and in a repetitive subunit of the fiber bundles. The loading history was incorporated into a damage accumulation model in order to estimate the platelet activation state (PAS) associated with repeated passes of the blood within the device. Our results highlighted the presence of blood stagnation areas in the inlet section that significantly increased the platelet activation levels in particles remaining trapped in this region. The order of magnitude of PAS in the device was the same as the one calculated for the components of the ECC tubing system, chosen as a term of comparison for their extensive diffusion. Interpolating the mean PAS values with respect to the number of passes, we obtained a straightforward prediction of the thrombogenic potential as a function of the duration of ECC.
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Abstract
Endotoxin, an outer membrane component of gram-negative bacteria, plays an important role in the pathogenesis of septic shock. Endotoxin adsorption therapy by polymyxin B-immobilized fiber column hemoperfusion (PMX) has been used for the treatment of septic shock patients in Japan since 1994. The covalent binding of polymyxin B onto the surface of the polystyrene-based carrier fiber in PMX inactivates the endotoxin in the blood without exerting toxicity. This study was performed as a systematic review to evaluate the efficacy and mechanism of PMX treatment in patients with septic shock. The PubMed database and references from identified articles were used to search and review the literature relating to the efficacy and mechanism of PMX treatment in patients with septic shock. Polymyxin B-immobilized fiber column hemoperfusion adsorbed monocytes, activated neutrophils, and anandamide, as well as endotoxin through direct covalent bond, hydrophobic and ionic interactions, and hydrodynamics, and reduced the blood concentrations of inflammatory cytokines, plasminogen activator inhibitor 1 and adhesion molecules. Polymyxin B-immobilized fiber column hemoperfusion increased blood pressure and reduced the dosage requirements for vasopressive/inotropic agents. The meta-analysis showed that PMX treatment had beneficial effects on the hemodynamics, pulmonary oxygenation, and mortality. These beneficial effects may be attributable to the direct adsorption of endotoxin, monocytes, activated neutrophils, and anandamide, as well as indirect decrease in inflammatory cytokines and other mediators. Polymyxin B-immobilized fiber column hemoperfusion treatment has additional effects on reducing endothelial damage, proapoptotic activity, and immunosuppression. Further studies will be needed to confirm the efficacy and mechanism of PMX treatment in septic shock.
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18
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Apheresis of activated leukocytes with an immobilized polymyxin B filter in patients with septic shock. Shock 2011; 34:461-6. [PMID: 20386499 DOI: 10.1097/shk.0b013e3181e14ca0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In this study, we examined the effects of direct hemoperfusion through filters with immobilized polymyxin B (PMX-DHP) on leukocyte function and plasma levels of cytokines in patients with septic shock. We found that PMX-DHP caused increased expression of C-X-C chemokine receptor 1 (CXCR1) and CXCR2, along with decreased expression of CD64 and CD11b, by circulating neutrophils in patients with septic shock. Plasma levels of cytokines, including interleukin 6 (IL-6), IL-8, IL-10, and high-mobility group box 1, were elevated in patients with septic shock compared with healthy controls, but cytokine levels were not altered by PMX-DHP. These results suggest that PMX-DHP influences neutrophils via a mechanism that does not involve cytokine. Ex vivo perfusion of heparinized blood from patients with sepsis and septic shock through PMX filters in a laboratory circuit caused a significant decrease in neutrophil and monocyte counts. After 120 min of perfusion, neutrophils, monocytes, and lymphocytes were decreased by 78%, 70%, and 10%, respectively, compared with baseline values. Flow cytometric analysis indicated that activated neutrophils with high levels of CD11b/CD64 expression and low levels of CXCR1/CXCR2 expression showed preferential adhesion to PMX filters. Neutrophils isolated from the blood after ex vivo PMX perfusion caused less damage to an endothelial cell monolayer than cells from sham-treated blood, whereas neutrophil phagocytosis of opsonized Escherichia coli was unaffected. These results indicate that PMX-DHP selectively removes activated neutrophils and reduces the ability of circulating cells to cause endothelial damage. Selective removal of activated neutrophils using PMX-DHP may improve the systemic inflammatory response in patients with septic shock.
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19
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Novelli G, Ferretti G, Poli L, Pretagostini R, Ruberto F, Perrella S, Levi S, Morabito V, Berloco P. Clinical Results of Treatment of Postsurgical Endotoxin-Mediated Sepsis With Polymyxin-B Direct Hemoperfusion. Transplant Proc 2010; 42:1021-4. [DOI: 10.1016/j.transproceed.2010.03.056] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Shrestha A, Li R, Sil D, Pardeshi NN, Schwarting N, Schorno KS, Rajewski RA, Datta A, David SA. Pharmacokinetics of DS-96, an alkylpolyamine lipopolysaccharide sequestrant, in rodents. J Pharm Sci 2009; 97:5376-85. [PMID: 18383338 DOI: 10.1002/jps.21361] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The pharmacokinetics of DS-96, an N-alkylhomospermine analog designed to sequester bacterial lipopolysaccharides, has been determined in rodent species. The elimination half-life in mice and rats are about 400 and 500 min, respectively, with other PK parameters being quite similar in the two rodent species. Interestingly, the mouse intravenous plasma concentration time curves exhibit an apparent absorption phase. While the rat intravenous data did not exhibit a pronounced apparent absorption phase immediately following injection, plasma levels did increase between 10 and 30 min following an expected drop from time 0 to 5 min. The data are consistent with first-pass uptake, possibly by the lung, with back diffusion as a function of time. The observed C(max) values of 1.36 microg/mL in the mouse intraperitoneal model suggest that a plasma concentration of 0.5-1 microg/mL corresponds to complete protection for a 200 ng/animal dose of intraperitoneally administered LPS in the D-galactosamine-primed model of endotoxin-induced lethality.
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Affiliation(s)
- Anurupa Shrestha
- Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas, USA
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21
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Wu W, Sil D, Szostak ML, Malladi SS, Warshakoon HJ, Kimbrell MR, Cromer JR, David SA. Structure-activity relationships of lipopolysaccharide sequestration in guanylhydrazone-bearing lipopolyamines. Bioorg Med Chem 2009; 17:709-15. [PMID: 19064323 PMCID: PMC3702171 DOI: 10.1016/j.bmc.2008.11.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Revised: 11/15/2008] [Accepted: 11/18/2008] [Indexed: 11/17/2022]
Abstract
The toxicity of gram-negative bacterial endotoxin (lipopolysaccharide, LPS) resides in its structurally highly conserved glycolipid component called lipid A. Our major goal has been to develop small-molecules that would sequester LPS by binding to the lipid A moiety, so that it could be useful for the prophylaxis or adjunctive therapy of gram-negative sepsis. We had previously identified in rapid-throughput screens several guanylhydrazones as potent LPS binders. We were desirous of examining if the presence of the guanylhydrazone (rather than an amine) functionality would afford greater LPS sequestration potency. In evaluating a congeneric set of guanylhydrazone analogues, we find that C(16) alkyl substitution is optimal in the N-alkylguanylhydrazone series; a homospermine analogue with the terminal amine N-alkylated with a C(16) chain with the other terminus of the molecule bearing an unsubstituted guanylhydrazone moiety is marginally more active, suggesting very slight, if any, steric effects. Neither C(16) analogue is significantly more active than the N-C(16)-alkyl or N-C(16)-acyl compounds that we had characterized earlier, indicating that basicity of the phosphate-recognizing cationic group, is not a determinant of LPS sequestration activity.
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Affiliation(s)
- Wenyan Wu
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045
| | - Diptesh Sil
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045
| | - Michal L. Szostak
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045
| | | | | | | | - Jens R. Cromer
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045
| | - Sunil A. David
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66045
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22
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Nguyen TB, Adisechan AK, Suresh Kumar EVK, Balakrishna R, Kimbrell MR, Miller KA, Datta A, David SA. Protection from endotoxic shock by EVK-203, a novel alkylpolyamine sequestrant of lipopolysaccharide. Bioorg Med Chem 2007; 15:5694-709. [PMID: 17583517 PMCID: PMC2039869 DOI: 10.1016/j.bmc.2007.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Revised: 06/01/2007] [Accepted: 06/05/2007] [Indexed: 11/20/2022]
Abstract
Lipopolysaccharides (LPS) play a key role in the pathogenesis of septic shock, a major cause of mortality in the critically ill patient. The only therapeutic option aimed at limiting downstream systemic inflammatory processes by targeting lipopolysaccharide is Toraymyxin, an extracorporeal hemoperfusion device using solid phase-immobilized polymyxin B (PMB). While PMB is known to effectively sequester LPS, its severe systemic toxicity proscribes its parenteral use, and hemoperfusion may not be feasible in patients in shock. In our continuing efforts to develop small-molecule mimics which display the LPS-sequestering properties, but not the toxicity of PMB, a series of mono- and bis-substituted dialkylpolyamines were synthesized and evaluated. We show that EVK-203, an alkylpolyamine compound, specifically binds to and neutralizes the activity of LPS, and affords complete protection in a murine model of endotoxic shock. EVK-203 is without any apparent toxicity when administered to mice at multiples of therapeutic doses for several days. The specific endotoxin-sequestering property along with a very favorable therapeutic index renders this compound an ideal candidate for preclinical development.
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Affiliation(s)
- Thuan B Nguyen
- Department of Medicinal Chemistry, University of Kansas, Multidisciplinary Research Building, Lawrence, KS 66047, USA
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23
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Sil D, Shrestha A, Kimbrell MR, Nguyen TB, Adisechan AK, Balakrishna R, Abbo BG, Malladi S, Miller KA, Short S, Cromer JR, Arora S, Datta A, David SA. Bound to shock: protection from lethal endotoxemic shock by a novel, nontoxic, alkylpolyamine lipopolysaccharide sequestrant. Antimicrob Agents Chemother 2007; 51:2811-9. [PMID: 17548488 PMCID: PMC1932507 DOI: 10.1128/aac.00200-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipopolysaccharide (LPS), or endotoxin, a structural component of gram-negative bacterial outer membranes, plays a key role in the pathogenesis of septic shock, a syndrome of severe systemic inflammation which leads to multiple-system organ failure. Despite advances in antimicrobial chemotherapy, sepsis continues to be the commonest cause of death in the critically ill patient. This is attributable to the lack of therapeutic options that aim at limiting the exposure to the toxin and the prevention of subsequent downstream inflammatory processes. Polymyxin B (PMB), a peptide antibiotic, is a prototype small molecule that binds and neutralizes LPS toxicity. However, the antibiotic is too toxic for systemic use as an LPS sequestrant. Based on a nuclear magnetic resonance-derived model of polymyxin B-LPS complex, we had earlier identified the pharmacophore necessary for optimal recognition and neutralization of the toxin. Iterative cycles of pharmacophore-based ligand design and evaluation have yielded a synthetically easily accessible N(1),mono-alkyl-mono-homologated spermine derivative, DS-96. We have found that DS-96 binds LPS and neutralizes its toxicity with a potency indistinguishable from that of PMB in a wide range of in vitro assays, affords complete protection in a murine model of LPS-induced lethality, and is apparently nontoxic in vertebrate animal models.
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Affiliation(s)
- Diptesh Sil
- Department of Medicinal Chemistry, University of Kansas, Multidisciplinary Research Building, Lawrence, KS 66047, USA
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24
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Burns MR, Jenkins SA, Kimbrell MR, Balakrishna R, Nguyen TB, Abbo BG, David SA. Polycationic Sulfonamides for the Sequestration of Endotoxin. J Med Chem 2007; 50:877-88. [PMID: 17256835 DOI: 10.1021/jm061198m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Lipopolysaccharides (LPS) play a key role in the pathogenesis of septic shock, a major cause of mortality in the critically ill patient. We had previously shown that monoacylated polyamine compounds specifically bind to and neutralize the activity of LPS with high in vitro potency and afford complete protection in a murine model of endotoxic shock. Fatty acid amides of polyamines may be rapidly cleared from systemic circulation due to their susceptibility to nonspecific serum amidases and, thus, would be predicted to have a short duration of action. In a systematic effort to increase the likelihood of better bioavailability properties together with structural modifications that may result in gains in activity, we now report structure-activity relationships pertaining to endotoxin-binding and -neutralizing activities of homologated polyamine sulfonamides.
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Affiliation(s)
- Mark R Burns
- MediQuest Therapeutics, Inc., 22322 20th Avenue SE, Bothell, Washington 98021, USA.
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