scholarly journals Self-Assembling Quaternary Ammonium Sulfonamide Antimicrobials

2021 ◽  
Author(s):  
Kamlesh Mistry
Keyword(s):  
Stainless Steel ◽  
Quaternary Ammonium ◽  
Contact Time ◽  
Metal Surfaces ◽  
Room Temperature ◽  
Uv Curing ◽  
Water Soluble ◽  
Antimicrobial Coatings ◽  
Self Assembling ◽  
Plastic Surfaces

A series of novel sulfonamide based quaternary ammonium (QUAT’s) antimicrobials containing a variety of chemical anchors R-SO2-NH-(CH2)3-N(CH3)2-(CH2)3-Y (where R = alkyl or aryl and Y = organosilane (Si(OMe)3), organophosphorus (P(O)(OR1)) and benzophenone (-OC6H4-C(O)-C6H5)) were used to immobilize them on different substrates. Sulfonamide organosilane QUAT’s were immobilized on to textiles substrates, whereas benzophenone QUAT’s were used to exclusively coat plastic surfaces (polyethylene (PE), and polyvinylchloride (PVC)), and organophosphorus QUAT’s were prepared for testing on metal surfaces (stainless steel). The covalently attached antimicrobial coatings were found to kill gram +ve and -ve bacteria on contact, hindering their attachment and colonization without any leachate. The partially water soluble sulfonamide QUAT’s presented are readily prepared, easy to apply and are relatively inexpensive. Textile samples were prepared by immersion in a MeOH:H2O (30:70) solution of organosilane QUAT’s followed by curing/drying at room temperature for 2 – 24 hours. Plastic samples were prepared by electrospraying an EtOH:H2O (10:90) solution containing benzophenone QUAT’s followed by UV curing using for 2 – 5 minutes. All samples showed a 100% reduction (107– 106 cells) of viable Arthrobacter, S. aureus, and E.coli after 3 hours of contact time and maintained their activity over 24 hours versus the control (untreated) samples.

scholarly journals Self-Assembling Quaternary Ammonium Sulfonamide Antimicrobials

2021 ◽  
Author(s):  
Kamlesh Mistry
Keyword(s):  
Stainless Steel ◽  
Quaternary Ammonium ◽  
Contact Time ◽  
Metal Surfaces ◽  
Room Temperature ◽  
Uv Curing ◽  
Water Soluble ◽  
Antimicrobial Coatings ◽  
Self Assembling ◽  
Plastic Surfaces

A series of novel sulfonamide based quaternary ammonium (QUAT’s) antimicrobials containing a variety of chemical anchors R-SO2-NH-(CH2)3-N(CH3)2-(CH2)3-Y (where R = alkyl or aryl and Y = organosilane (Si(OMe)3), organophosphorus (P(O)(OR1)) and benzophenone (-OC6H4-C(O)-C6H5)) were used to immobilize them on different substrates. Sulfonamide organosilane QUAT’s were immobilized on to textiles substrates, whereas benzophenone QUAT’s were used to exclusively coat plastic surfaces (polyethylene (PE), and polyvinylchloride (PVC)), and organophosphorus QUAT’s were prepared for testing on metal surfaces (stainless steel). The covalently attached antimicrobial coatings were found to kill gram +ve and -ve bacteria on contact, hindering their attachment and colonization without any leachate. The partially water soluble sulfonamide QUAT’s presented are readily prepared, easy to apply and are relatively inexpensive. Textile samples were prepared by immersion in a MeOH:H2O (30:70) solution of organosilane QUAT’s followed by curing/drying at room temperature for 2 – 24 hours. Plastic samples were prepared by electrospraying an EtOH:H2O (10:90) solution containing benzophenone QUAT’s followed by UV curing using for 2 – 5 minutes. All samples showed a 100% reduction (107– 106 cells) of viable Arthrobacter, S. aureus, and E.coli after 3 hours of contact time and maintained their activity over 24 hours versus the control (untreated) samples.

scholarly journals Detection and antimicrobial activity of immobilized quaternary ammonium antimicrobial monolayers on porous and non-porous surfaces.

2021 ◽  
Author(s):  
Lukasz Porosa
Keyword(s):  
Antimicrobial Activity ◽  
Phosphonic Acid ◽  
Quaternary Ammonium ◽  
Contact Time ◽  
Metal Surfaces ◽  
Noble Metals ◽  
Environmental Safety ◽  
Dip Coating ◽  
Surface Attachment ◽  
Thin Film Coatings

This research describes the development of novel, environmentally-friendly, non-releasing contact-active thin film coatings by immobilizing the quaternary ammonium (QA) antimicrobial group on a multitude of surfaces. Various chemical anchors based on organosilanes (i.e. textiles, silica, oxide surfaces), organosulfur comprising of thiol (noble metals), organophosphorus comprising of phosphonate and phosphonic acid (i.e. stainless steel (SS), titanium (Ti)), and catechol (Ti, SS) monolayers are employed to attach the QA antimicrobial onto metal surfaces, while benzophenone photoactive crosslinkers containing QA groups are used to coat plastic surfaces (C-H surfaces, i.e. polyethylene (PE), silicone (Si), polyvinylchloride (PVC)). Surfaces treated with covalently attached antimicrobial coatings function by killing microbes on contact, preventing surface attachment, colonization and contamination without releasing the chemical into the environment. The advantages of this method of delivery of the antimicrobial include a lower cost of application, decreased antimicrobial resistance, lower toxicity and increased environmental safety. Samples prepared by an overnight immersion in an ethanolic solution of phosphorus containing quats followed by an overnight cure at 100oC showed the highest antimicrobial reduction versus electrospray application and no curing. Short chain phosphonic acid quats and the organosilane quat were inactive on titanium. Antimicrobial activity of long chain phosphonate quats prepared by dip coating and annealing on metal surfaces (Ti, SS, Al) was tested by growth enumeration in the dry state utilizing methods developed in the Wolfaardt lab. All samples showed a 100% reduction (106 cells) of viable Salmonella, Arthrobacter, S.aureus and P.aeroguinosa after 2 hrs of contact time and maintained their activity over 24 hrs versus the uncoated controls. To demonstrate the phosphonate quats were truly immobilized, Ti samples from the first trial were washed in distilled H2O, dried, and re-innoculated with 106 Anthrobacter colonies. No visible colonies of Anthrobacter remained after 2 hrs of contact time with the Ti surfaces indicating a contact killing mechanism at play.

scholarly journals Unusual Enthalpy Driven Self Assembly at Room Temperature with Chitosan Amphiphiles

2019 ◽  
Vol 7 (1) ◽  
pp. 57-71 ◽  
Author(s):  
Uchechukwu Odunze ◽  
Fionn O'Brien ◽  
Lisa Godfrey ◽  
Andreas Schätzlein ◽  
Ijeoma Uchegbu
Keyword(s):  
Molecular Weight ◽  
Negative Correlation ◽  
Quaternary Ammonium ◽  
Self Assembly ◽  
Room Temperature ◽  
Isothermal Calorimetry ◽  
Relative Proportion ◽  
Polymer Molecular Weight ◽  
Self Assembling ◽  
Micellar Aggregates

Background: GCPQ (N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trimethyl- 6-O-glycolchitosan) is a self-assembling polymer being investigated as a pharmaceutical nano-carrier. GCPQ nanoparticles shuttle drugs across biological barriers, improving drug performance. The exact chemistry of GCPQ is varied by the relative proportion of hydrophobic (N-palmitoyl) and hydrophilic (quaternary ammonium) groups and molecular weight. Objective: We hypothesised that the thermodynamics of self-assembly is controlled by the polymer molecular weight and hydrophobicity. Method: The thermodynamics of self-assembly was investigated using isothermal calorimetry. Results: GCPQs (Mw = 8-15 kDa) formed micellar aggregates at critical micellar concentrations of 1-2.4 µM at 25°C and micellisation was unusually enthalpy driven. There was a positive correlation between ΔHmic and mole% quaternary groups (Q): ΔHmic = 3.8 Q- 159 (r2 = 0.93) and a negative correlation between ΔHmic and molecular weight (Mw): ΔHmic = -13.5 Mw-26.3 (r2 = 0.99). Conclusion: These findings provide insights into the positive drivers of stable selfassemblies, namely hydrophobicity and molecular weight, as both hydrophobicity and molecular weight are associated with an increased enthalpy contribution to micellisation.

Bacillus anthracis Spore Decontamination in Food Grease

2013 ◽  
Vol 76 (4) ◽  
pp. 699-701 ◽  
Author(s):  
KINGSLEY K. AMOAKO ◽  
KRISTINA SANTIAGO-MATEO ◽  
MICHAEL J. SHIELDS ◽  
ELIZABETH ROHONCZY
Keyword(s):  
Hydrogen Peroxide ◽  
Stainless Steel ◽  
Bacillus Anthracis ◽  
Sodium Hypochlorite ◽  
Contact Time ◽  
Room Temperature ◽  
Surface Decontamination

Bacillus anthracis Sterne strain spores were analyzed for their resistance against five disinfectants: commercial sodium hypochlorite, Spor-Klenz Ready-to-Use Cold Sterilant, Accelerated Hydrogen Peroxide (AHP), Virkon, and Surface Decontamination Foam (SDF). The aim of this study was to find an effective disinfectant that would reduce the viability of B. anthracis Sterne spores at ≥6 log in the presence of variables such as animal grease and fat, stainless steel, and temperature (room temperature and 4°C). SDF and 10%sodium hypochlorite consistently reduced the growth of viable B. anthracis Sterne spores after 5 min in the presence of stainless steel at room temperature. It took at least 10 min of contact time for AHP to consistently reduce spore growth by ≥6 log, while it took at least 20 min for 5% bleach and Spor-Klenz to consistently inactivate ≥6 log spores in the presence of stainless steel at room temperature. AHP was the only disinfectant that reduced the viability of B. anthracis Sterne spores at ≥6 log in the presence of stainless steel and animal grease, both at room temperature and 4°C after 24 h of contact time.

scholarly journals Detection and antimicrobial activity of immobilized quaternary ammonium antimicrobial monolayers on porous and non-porous surfaces.

2021 ◽  
Author(s):  
Lukasz Porosa
Keyword(s):  
Antimicrobial Activity ◽  
Phosphonic Acid ◽  
Quaternary Ammonium ◽  
Contact Time ◽  
Metal Surfaces ◽  
Noble Metals ◽  
Environmental Safety ◽  
Dip Coating ◽  
Surface Attachment ◽  
Thin Film Coatings

This research describes the development of novel, environmentally-friendly, non-releasing contact-active thin film coatings by immobilizing the quaternary ammonium (QA) antimicrobial group on a multitude of surfaces. Various chemical anchors based on organosilanes (i.e. textiles, silica, oxide surfaces), organosulfur comprising of thiol (noble metals), organophosphorus comprising of phosphonate and phosphonic acid (i.e. stainless steel (SS), titanium (Ti)), and catechol (Ti, SS) monolayers are employed to attach the QA antimicrobial onto metal surfaces, while benzophenone photoactive crosslinkers containing QA groups are used to coat plastic surfaces (C-H surfaces, i.e. polyethylene (PE), silicone (Si), polyvinylchloride (PVC)). Surfaces treated with covalently attached antimicrobial coatings function by killing microbes on contact, preventing surface attachment, colonization and contamination without releasing the chemical into the environment. The advantages of this method of delivery of the antimicrobial include a lower cost of application, decreased antimicrobial resistance, lower toxicity and increased environmental safety. Samples prepared by an overnight immersion in an ethanolic solution of phosphorus containing quats followed by an overnight cure at 100oC showed the highest antimicrobial reduction versus electrospray application and no curing. Short chain phosphonic acid quats and the organosilane quat were inactive on titanium. Antimicrobial activity of long chain phosphonate quats prepared by dip coating and annealing on metal surfaces (Ti, SS, Al) was tested by growth enumeration in the dry state utilizing methods developed in the Wolfaardt lab. All samples showed a 100% reduction (106 cells) of viable Salmonella, Arthrobacter, S.aureus and P.aeroguinosa after 2 hrs of contact time and maintained their activity over 24 hrs versus the uncoated controls. To demonstrate the phosphonate quats were truly immobilized, Ti samples from the first trial were washed in distilled H2O, dried, and re-innoculated with 106 Anthrobacter colonies. No visible colonies of Anthrobacter remained after 2 hrs of contact time with the Ti surfaces indicating a contact killing mechanism at play.

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

Water-Soluble Imine Ligand/Palladium-Catalyzed Suzuki Reaction at Room Temperature

2010 ◽  
Vol 31 (10) ◽  
pp. 1277-1280
Author(s):  
Chun LIU ◽  
Qijian NI ◽  
Pingping HU ◽  
Hao YUAN ◽  
Zilin JIN
Keyword(s):  
Room Temperature ◽  
Suzuki Reaction ◽  
Water Soluble ◽  
Palladium Catalyzed

Dynamics of Anthracene Excimer Formation within a Water-Soluble Nanocavity at Room Temperature

2021 ◽  
Vol 143 (4) ◽  
pp. 2025-2036
Author(s):  
Aritra Das ◽  
Ashwini Danao ◽  
Shubhojit Banerjee ◽  
A. Mohan Raj ◽  
Gaurav Sharma ◽  
...  
Keyword(s):  
Room Temperature ◽  
Water Soluble ◽  
Excimer Formation

Hierarchical nanostructures self-assembled from δ-MnO2 ultrathin nanosheets and Mn3O4 octahedrons for efficient room-temperature HCHO oxidation

2021 ◽  
Author(s):  
Lifang Qi ◽  
Yao Le ◽  
Chao Wang ◽  
Rui Lei ◽  
Tian Wu
Keyword(s):  
Room Temperature ◽  
Hierarchical Nanostructures ◽  
Low Level ◽  
Ultrathin Nanosheets ◽  
Self Assembling ◽  
Formaldehyde Oxidation ◽  
Self Assembled

Self-assembling ultrathin active δ-MnO2 nanosheets and Mn3O4 octahedrons into hierarchical texture enhances room-temperature formaldehyde oxidation at a low-level of Pt.

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