Encountering the Survival Strategies Using Various Nano Assemblages

2021 ◽  
pp. 159-187
Author(s):  
Lakshmipathy Muthukrishnan
Keyword(s):  
Antimicrobial Resistance ◽  
Chemical Properties ◽  
Fine Tuning ◽  
Survival Strategies ◽  
Natural Phenomenon ◽  
Physico Chemical ◽  
Life Threatening ◽  
Medicinal Properties ◽  
Micro Organisms ◽  
Microbial Systems

The technological advancements have not only made humans more civilized but have also caused the micro-organisms to develop several survival strategies via antimicrobial resistance to keep pace. Such highly developed microbial systems have been classified as superbugs, exhibiting Trojan-horse mechanism. This uncertain behaviour in microbes has challenged humans to scour around novel moiety to shield themselves from the detrimental effects. One such natural phenomenon that has drawn the attention of researchers is the metal-microbe interaction where microbes were found to be controlled during their interaction with metals. Fine tuning could bestow them with enhanced physico-chemical properties capable of controlling life-threatening micro-organisms. Nano forms of metals (nanoparticles, quantum dots, polymeric nanostructures) exhibiting medicinal properties have been implied toward biomedical theranostics. This chapter highlights the mechanistic antimicrobial resistance and the containment strategy using various nano assemblage highlighting its fabrication and bio-molecular interaction.

Physical Chemistry of the Interface between Attached Micro-Organisms and Their Support

1990 ◽  
Vol 22 (1-2) ◽  
pp. 1-16 ◽  
Author(s):  
P. G. Rouxhet ◽  
N. Mozes
Keyword(s):  
Photoelectron Spectroscopy ◽  
Bacterial Adhesion ◽  
Surface Composition ◽  
Chemical Properties ◽  
Dlvo Theory ◽  
Support Surface ◽  
X Ray ◽  
Polymer Molecules ◽  
Physico Chemical ◽  
Micro Organisms

The thermodynamic approach of adhesion and DLVO theory are complementary to predict initial bacterial adhesion; the interplay between short- and long-range forces, respectively, may be due to surface roughness. Due to the influence of electrical double layer interactions, adhesion can be promoted by treatments leading to modification of the cell or support surface properties. Adhesion is influenced by cell-cell interactions, by the cpresence of polymer molecules on the surface and by the composition of the medium. X-ray photoelectron spectroscopy can be applied to determine the elemental composition of the surface of microorganisms; some information on the chemical functions can also be obtained. The surface composition is related to physico-chemical properties which play a determining role in adhesion and flocculation, in particular the hydrophobicity and the zeta potential.

scholarly journals Lactoperoxidase: physico-chemical properties, occurrence, mechanism of action and applications

2000 ◽  
Vol 84 (S1) ◽  
pp. 19-25 ◽  
Author(s):  
Klaas D. Kussendrager ◽  
A. C. M. van Hooijdonk
Keyword(s):  
Mammalian Cells ◽  
Bovine Milk ◽  
Chemical Properties ◽  
Mechanisms Of Action ◽  
Industrial Processes ◽  
Physico Chemical ◽  
Lactoperoxidase System ◽  
Wide Range ◽  
Occurrence Mechanism ◽  
Micro Organisms

Lactoperoxidase (LP) is one of the most prominent enzymes in bovine milk and catalyses the inactivation of a wide range of micro-organisms in the lactoperoxidase system (LP-s). LP-systems are also identified as natural antimicrobial systems in human secretions such as saliva, tear-fluid and milk and are found to be harmless to mammalian cells. The detailed molecular structure of LP is identified and the major products generated by the LP-s and their antimicrobial action have been elucidated for the greater part. In this paper several aspects of bovine LP and LP-s are discussed, including physico-chemical properties, occurrence in milk and colostrum and mechanisms of action. Since the introduction of industrial processes for the isolation of LP from milk and whey the interest in this enzyme has increased considerably and attention will be paid to potential and actual applications of LP-systems as biopreservatives in food and other products.

scholarly journals Revisiting of the physico-chemical properties of polyelectrolyte multilayers for a fine tuning of the immobilization of bacteria or nanoparticles

2020 ◽  
Vol 713 ◽  
pp. 138345
Author(s):  
I. Gammoudi ◽  
M. Mathelié-Guinlet ◽  
Z. Benabdallah ◽  
F. Moroté ◽  
H. Kahli ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Polyelectrolyte Multilayers ◽  
Fine Tuning ◽  
Physico Chemical

scholarly journals Bis(trifluoromethylsulfonyl)imide Ionic Liquids Applied for Fine-Tuning the Cure Characteristics and Performance of Natural Rubber Composites

2021 ◽  
Vol 22 (7) ◽  
pp. 3678
Author(s):  
Anna Sowińska ◽  
Magdalena Maciejewska ◽  
Anna Grajewska
Keyword(s):  
Ionic Liquids ◽  
Natural Rubber ◽  
Crosslink Density ◽  
Chemical Properties ◽  
Fine Tuning ◽  
Crosslinking Degree ◽  
Cure Characteristics ◽  
Physico Chemical ◽  
Elastomer Composites ◽  
And Performance

The goal of this work was to apply ionic liquids (ILs) with bis(trifluoromethylsulfonyl)imide anion (TFSI) for fine-tuning the cure characteristics and physico-chemical properties of elastomer composites based on a biodegradable natural rubber (NR) matrix. ILs with TFSI anion and different cations, such as alkylpyrrolidinium, alkylammonium, and alkylsulfonium cations, were applied to increase the efficiency of sulfur vulcanization and to improve the performance of NR composites. Thus, the influence of ILs on the vulcanization of NR compounds, as well as crosslink density and physical properties of NR vulcanizates, including tensile properties, thermal stability, and resistance to thermo-oxidative aging was explored. The activity of ILs seems to be strongly dependent on their cation. Pyrrolidinium and ammonium ILs effectively supported the vulcanization, reducing the optimal vulcanization time and temperature of NR compounds and increasing the crosslink density of the vulcanizates. Consequently, vulcanizates with these ILs exhibited higher tensile strength than the benchmark without IL. On the other hand, sulfonium ILs reduced the torque increment owing to the lower crosslinking degree of elastomer but significantly improved the resistance of NR composites to thermo-oxidation. Thus, TFSI ILs can be used to align the curing behavior and performance of NR composites for particular applications.

Effect of biofilm on colloid attachment in saturated porous media

2014 ◽  
Vol 70 (2) ◽  
pp. 241-248 ◽  
Author(s):  
Udayan Majumdar ◽  
Thrisha Alexander ◽  
Morris Waskar ◽  
Manoj V. Dagaonkar
Keyword(s):  
Porous Media ◽  
Extracellular Polymeric Substances ◽  
Colloidal Particles ◽  
Early Stage ◽  
Critical Role ◽  
Chemical Properties ◽  
Extended Aging ◽  
Physico Chemical ◽  
Aging Study ◽  
Micro Organisms

Biofilm plays an important role in controlling the transport of colloids in a porous media. Biofilms are formed when micro-organisms come in contact with substrates, and are able to attach and grow with availability of nutrients. The microorganisms get embedded in a matrix of the substrate and extracellular polymeric substances which are responsible for the morphology, physico-chemical properties, structure and coherence of the biofilm. In this study, the effect of biofilm and its aging on colloid removal was studied on a glass bead column. Oocysts, polystyrene microspheres and inorganic colloids were used as colloidal particles. Pseudomonas aeruginosa was used as a model biofilm-forming microorganism. Presence of biofilm significantly enhanced colloid removal in the column. After 3 weeks, almost complete colloid removal was observed. The formation of biofilm was confirmed by various physical characterization techniques. During the extended aging study, biofilm sloughed off under shear stress. The loss of biofilm was higher during the early stage of its growth, and subsequently slowed down probably due to the formation of a more rigid biofilm. This research indicates that biofilm formation, maturation and sloughing-off play a critical role in colloid removal through porous media.

scholarly journals Bottom-Up Design Approach for OBOC Peptide Libraries

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3316 ◽  
Author(s):  
Daniela Kalafatovic ◽  
Goran Mauša ◽  
Dina Rešetar Maslov ◽  
Ernest Giralt
Keyword(s):  
Chemical Space ◽  
Chemical Properties ◽  
Peptide Libraries ◽  
Fine Tuning ◽  
Design Approach ◽  
Bottom Up ◽  
Active Peptides ◽  
Physico Chemical ◽  
Library Complexity

One-bead-one-compound peptide libraries, developed following the top-down experimental approach, have attracted great interest in the identification of potential ligands or active peptides. By exploiting a reverse experimental design approach based on the bottom-up strategy, we aimed to develop simplified, maximally diverse peptide libraries that resulted in the successful characterization of mixture components. We show that libraries of 32 and 48 components can be successfully detected in a single run using chromatography coupled to mass spectrometry (UPLC-MS). The proposed libraries were further theoretically evaluated in terms of their composition and physico-chemical properties. By combining the knowledge obtained on single libraries we can cover larger sequence spaces and provide a controlled exploration of the peptide chemical space both theoretically and experimentally. Designing libraries by using the bottom-up approach opens up the possibility of rationally fine-tuning the library complexity based on the available analytical methods.

Green synthesized Silver Nanoparticles as Silver Lining in Antimicrobial Resistance: A Review

2021 ◽  
Vol 18 ◽  
Author(s):  
Sonia Parashar ◽  
Manish Kumar Sharma ◽  
Chanchal Garg ◽  
Munish Garg
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Resistance ◽  
Green Synthesis ◽  
Chemical Properties ◽  
Positive Role ◽  
Physico Chemical ◽  
Green Synthesized Silver Nanoparticles ◽  
Insight Into ◽  
Silver Lining

: Unprincipled use of antibiotics has led to the antimicrobial resistance (AMR) against mostly available compounds and now become a major cause of concern for the scientific community. However, in the past decade, green synthesized silver nanoparticles (AgNPs) have received greater attention for the development of newer therapies as antimicrobials by virtue of their unique physico-chemical properties. Unlike traditional antibiotics, AgNPs exert their action by acting on multiple mechanisms which make them potential candidates against AMR. Green synthesis of AgNPs using various medicinal plants has demonstrated broader spectrum of action against several microbes in a number of attempts. The present paper provides an insight into the scientific studies that have elucidated the positive role of plant extracts/phytochemicals during green synthesis of AgNPs and their future perspectives. The studies conducted so far seem promising still, a few factors like, the precise mechanism of action of AgNPs, their synergistic interaction with biomolecules, and industrial scalability need to be explored further till effective drug development using green synthesized AgNPs in healthcare systems against AMR is established.

scholarly journals Influence of Drug Incorporation on the Physico-Chemical Properties of Poly(l-Lactide) Implant Coating Matrices—A Systematic Study

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 292
Author(s):  
Daniela Arbeiter ◽  
Thomas Reske ◽  
Michael Teske ◽  
Dalibor Bajer ◽  
Volkmar Senz ◽  
...  
Keyword(s):  
Cyclosporine A ◽  
Chemical Properties ◽  
Tensile Tests ◽  
Local Drug Delivery ◽  
Physico Chemical ◽  
Thermal Measurements ◽  
Implant Coating ◽  
Life Threatening ◽  
And Performance ◽  
Drug Incorporation

Local drug delivery has become indispensable in biomedical engineering with stents being ideal carrier platforms. While local drug release is superior to systemic administration in many fields, the incorporation of drugs into polymers may influence the physico-chemical properties of said matrix. This is of particular relevance as minimally invasive implantation is frequently accompanied by mechanical stresses on the implant and coating. Thus, drug incorporation into polymers may result in a susceptibility to potentially life-threatening implant failure. We investigated spray-coated poly-l-lactide (PLLA)/drug blends using thermal measurements (DSC) and tensile tests to determine the influence of selected drugs, namely sirolimus, paclitaxel, dexamethasone, and cyclosporine A, on the physico-chemical properties of the polymer. For all drugs and PLLA/drug ratios, an increase in tensile strength was observed. As for sirolimus and dexamethasone, PLLA/drug mixed phase systems were identified by shifted drug melting peaks at 200 °C and 240 °C, respectively, whereas paclitaxel and dexamethasone led to cold crystallization. Cyclosporine A did not affect matrix thermal properties. Altogether, our data provide a contribution towards an understanding of the complex interaction between PLLA and different drugs. Our results hold implications regarding the necessity of target-oriented thermal treatment to ensure the shelf life and performance of stent coatings.

scholarly journals Influence of different excipients on the properties of hard gelatin capsules with metamizole sodium

2016 ◽  
Vol 29 (3) ◽  
pp. 114-117
Author(s):  
Magdalena Rogowska ◽  
Karol Iwaniak ◽  
Andrzej Polski ◽  
Karolina Slawinska ◽  
Karolina Sobotka-Polska ◽  
...  
Keyword(s):  
Microcrystalline Cellulose ◽  
Opioid Analgesic ◽  
Chemical Properties ◽  
Blood Disorders ◽  
Disintegration Time ◽  
Gelatin Capsules ◽  
Physico Chemical ◽  
Life Threatening ◽  
Metamizole Sodium ◽  
Hard Gelatin Capsules

Abstract Metamizole is an effective non-opioid analgesic drug used in the treatment of acute and chronic pain. Due to induced potentially life-threatening blood disorders, metamizole was withdrawn from market in many parts of the world, however, it is one of the most popular analgesics in Poland that is available as an over the counter drug. Patients tend to prefer capsules over tablets, as they are easier to swallow and taste better. The powder-filled capsules also have greater bioavailability and require less excipients, as compared to tablets. Polymic excipients are mainly used in capsule filling, and have influence upon the physico-chemical properties of the hard gelatin capsules and the powder formulation. The aim of the study was to determine whether various combinations of polymers impact the disintegration time and pharmaceutical availability of hard gelatin capsules with metamizole sodium. The results of our work demonstrated that the 80% of all active substance was released in all tested formulations within 15 minutes. Herein, the capsule containing lactose monohydrate had the longest release (4% after 2 min.), while capsules containing mannitol had the fastest release (81.2% after 2 min.). Moreover, the addition of HPMC to capsules with lactose brought about a slight increase in the metamizole release rate, while the addition of PVP 30 to capsules with microcrystalline cellulose slightly accelerated release. This data suggests that the use of different polymers in capsules formulation brings about changes in the physical properties of powders and modifies the release profile of metamizole. In our study, the most preferred formulation was one containing microcrystalline cellulose (good powder properties and fairly fast release).

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