pH-Degradable imidazolium oligomers as antimicrobial materials with tuneable loss of activity

2019 ◽  
Vol 7 (6) ◽  
pp. 2317-2325 ◽  
Author(s):  
Yuan Yuan ◽  
Diane S. W. Lim ◽  
Hong Wu ◽  
Hongfang Lu ◽  
Yiran Zheng ◽  
...  
Keyword(s):  
Bacterial Resistance ◽  
Ph Sensitive ◽  
Antimicrobial Materials ◽  
Active Fragments

Imidazolium oligomers containing pH-sensitive linkers degrade under basic conditions to less active fragments that slow the development of bacterial resistance.

scholarly journals Supercritical Fluid Applications in the Design of Novel Antimicrobial Materials

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2491 ◽  
Author(s):  
Irena Zizovic
Keyword(s):  
Antimicrobial Activity ◽  
High Pressure ◽  
Supercritical Fluid ◽  
Supercritical Fluids ◽  
Bacterial Resistance ◽  
Environmentally Friendly ◽  
Modern World ◽  
Resistance To Antibiotics ◽  
Antimicrobial Materials ◽  
The World

Bacterial resistance to antibiotics is one of the biggest problems in the modern world. The prevention of bacterial spreading from hospitals to the community and vice versa is an issue we have to deal with. This review presents a vast potential of contemporary high-pressure techniques in the design of materials with antimicrobial activity. Scientists from all over the world came up with ideas on how to exploit extraordinary properties of supercritical fluids in the production of advantageous materials in an environmentally friendly way. The review summarizes reported methods and results.

scholarly journals On-demand pH-sensitive surface charge-switchable polymeric micelles for targeting Pseudomonas aeruginosa biofilms development

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xiangjun Chen ◽  
Rong Guo ◽  
Changrong Wang ◽  
Keke Li ◽  
Xinyu Jiang ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Surface Charge ◽  
Bacterial Resistance ◽  
Polymeric Micelles ◽  
Effective Means ◽  
Ph Sensitive ◽  
Bacterial Biofilm ◽  
Mice Model ◽  
On Demand

AbstractBacterial biofilm is the complicated clinical issues, which usually results in bacterial resistance and reduce the therapeutic efficacy of antibiotics. Although micelles have been drawn attention in treatment of the biofilms, the micelles effectively permeate and retain in biofilms still facing a big challenge. In this study, we fabricated on-demand pH-sensitive surface charge-switchable azithromycin (AZM)-encapsulated micelles (denoted as AZM-SCSMs), aiming to act as therapeutic agent for treating Pseudomonas aeruginosa (P. aeruginosa) biofilms. The AZM-SCSMs was composed of poly(l-lactide)-polyetherimide-hyd-methoxy polyethylene glycol (PLA-PEI-hyd-mPEG). It was noteworthy that the pH-sensitive acylhydrazone bond could be cleaved in acidic biofilm microenvironment, releasing the secondary AZM-loaded cationic micelles based on PLA-PEI (AZM-SCMs) without destroying the micellar integrity, which could tailor drug-bacterium interaction using micelles through electrostatic attraction. The results proved that positively charged AZM-SCMs could facilitate the enhanced penetration and retention inside biofilms, improved binding affinity with bacterial membrane, and added drug internalization, thus characterized as potential anti-biofilm agent. The excellent in vivo therapeutic performance of AZM-SCSMs was confirmed by the targeting delivery to the infected tissue and reduced bacterial burden in the abscess-bearing mice model. This study not only developed a novel method for construction non-depolymerized pH-sensitive SCSMs, but also provided an effective means for the treatment of biofilm-related infections.

Permeability Enhancing and Chemotactic Activities of Lower Molecular Weight Degradation Products of Human Fibrinogen

1981 ◽  
Vol 45 (01) ◽  
pp. 090-094 ◽  
Author(s):  
Katsuo Sueishi ◽  
Shigeru Nanno ◽  
Kenzo Tanaka
Keyword(s):  
Molecular Weight ◽  
Degradation Products ◽  
Electron Microscopic Observation ◽  
Chemotactic Activity ◽  
Lower Molecular Weight ◽  
Electron Microscopic ◽  
Human Fibrinogen ◽  
Rabbit Skin ◽  
Molecular Weights ◽  
Active Fragments

SummaryFibrinogen degradation products were investigated for leukocyte chemotactic activity and for enhancement of vascular permeability. Both activities increased progressively with plasmin digestion of fibrinogen. Active fragments were partially purified from 24 hr-plasmin digests. Molecular weights of the permeability increasing and chemotactic activity fractions were 25,000-15,000 and 25,000 respectively. Both fractions had much higher activities than the fragment X, Y, D or E. Electron microscopic observation of the small blood vessels in rabbit skin correlated increased permeability with the formation of characteristic gaps between adjoining endothelial cells and their contraction.These findings suggest that lower molecular weight degradation products of fibrinogen may be influential in contributing to granulocytic infiltration and enhanced permeability in lesions characterized by deposits of fibrin and/or fibrinogen.

A Mechanism for Reversibly Pausing a Self-Immolation Cascade in Response to pH Changes

2019 ◽  
Author(s):  
Derrick Roberts ◽  
Ben S. Pilgrim ◽  
Tristan Dell ◽  
Molly Stevens
Keyword(s):  
Local Environment ◽  
Chemical Signals ◽  
Ph Sensitive ◽  
First Report ◽  
Ph Changes ◽  
Self Immolation

We describe the first report of a self-immolation cascade that can be reversibly paused and reactivated in response to pH changes. This system employs a triazole-based self-immolative linker, which expresses a pH-sensitive intermediate during its elimination sequence. This allows the system to respond to pH cues within its local environment, thus establishing a new way to gate self-immolative release using fluctuating or transient chemical signals.<br>

Isotopically Labeled Desthiobiotin Azide (isoDTB) Tags Enable Global Profiling of the Bacterial Cysteinome

2019 ◽  
Author(s):  
Patrick R. A. Zanon ◽  
Lisa Lewald ◽  
Stephan M. Hacker
Keyword(s):  
Binding Sites ◽  
Bacterial Resistance ◽  
Mevalonate Pathway ◽  
Rapid Development ◽  
High Reactivity ◽  
Functional Importance ◽  
Essential Proteins ◽  
Covalent Inhibitors ◽  
Druggable Targets ◽  
Covalent Ligands

Rapid development of bacterial resistance has led to an urgent need to find new druggable targets for antibiotics. In this context, residue-specific chemoproteomic approaches enable proteome-wide identification of binding sites for covalent inhibitors. Here, we describe isotopically labeled desthiobiotin azide (isoDTB) tags that are easily synthesized, shorten the chemoproteomic workflow and allow an increased coverage of cysteines in bacterial systems. We quantify 59% of all cysteines in essential proteins in <i>Staphylococcus aureus</i> and discover 88 cysteines with high reactivity, which correlates with functional importance. Furthermore, we identify 268 cysteines that are engaged by covalent ligands. We verify inhibition of HMG-CoA synthase, which will allow addressing the bacterial mevalonate pathway through a new target. Overall, a comprehensive map of the bacterial cysteinome is obtained, which will facilitate the development of antibiotics with novel modes-of-action.

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