scholarly journals Synthesis, Characterization and Bactericidal Activity of a 4-Ammoniumbuthylstyrene-Based Random Copolymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Silvana Alfei ◽  
Gabriella Piatti ◽  
Debora Caviglia ◽  
Anna Maria Schito
Keyword(s):  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
Random Copolymer ◽  
Water Soluble ◽  
Cationic Polymers ◽  
Severe Infections

The growing resistance of bacteria to current chemotherapy is a global concern that urgently requires new and effective antimicrobial agents, aimed at curing untreatable infection, reducing unacceptable healthcare costs and human mortality. Cationic polymers, that mimic antimicrobial cationic peptides, represent promising broad-spectrum agents, being less susceptible to develop resistance than low molecular weight antibiotics. We, thus, designed, and herein report, the synthesis and physicochemical characterization of a water-soluble cationic copolymer (P5), obtained by copolymerizing the laboratory-made monomer 4-ammoniumbuthylstyrene hydrochloride with di-methyl-acrylamide as uncharged diluent. The antibacterial activity of P5 was assessed against several multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species. Except for strains characterized by modifications of the membrane charge, most of the tested isolates were sensible to the new molecule. P5 showed remarkable antibacterial activity against several isolates of genera Enterococcus, Staphylococcus, Pseudomonas, Klebsiella, and against Escherichia coli, Acinetobacter baumannii and Stenotrophomonas maltophilia, displaying a minimum MIC value of 3.15 µM. In time-killing and turbidimetric studies, P5 displayed a rapid non-lytic bactericidal activity. Due to its water-solubility and wide bactericidal spectrum, P5 could represent a promising novel agent capable of overcoming severe infections sustained by bacteria resistant the presently available antibiotics.

scholarly journals CHARACTERIZATION OF DRUGS ENCAPSULATED INTO MESOPOROUS SILICA

2019 ◽  
pp. 7-11
Author(s):  
ARIF BUDIMAN
Keyword(s):  
Water Solubility ◽  
Drug Loading ◽  
Physicochemical Characterization ◽  
Amorphous State ◽  
Molecular State ◽  
Water Soluble ◽  
Crystal Nucleation ◽  
Formulation Development ◽  
Scanning Calorimetry

Solubility of the drug has a strong influence to achieve higher bioavailability of the drug in systemic circulation. More than 70% NCEs (new chemical entities) are hydrophobic, and practically difficult into solid formulation due to their poor water solubility. Mesoporous silicas (MSP) have been used for drug delivery system, especially for poorly water-soluble drugs. Encapsulation and interaction of drugs in MSP can enhance the delivery and maintain the stability of the drug. However, the characterization of the drug in MSP is necessary to confirm its molecular state. In this review, we present an overview of reports related to the characterization of drug encapsulated into MSP. Encapsulation of drugs in MSP can prevent recrystallization of drugs due to its inhibition of crystal nucleation. A porous material in MSP can maintain the drug in a physically stable amorphous state. The preventing of drug crystallization in MSP can enhance the solubility and the dissolution rate of drug. Therefore, in this work, attempts have been made to understand the molecular state of the drug in MSP. The physicochemical characterization of drug by transmission electron microscopy (TEM), scanning electron microscope (SEM), differential scanning calorimetry (DSC), fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (PXRD) and thermogravimetric analysis (TGA) were discussed. The effect of solvent and methods of drug loading and the effect of the shape of MSP on release profiles are also presented. Overall, this review provides information about the characterization of drug encapsulated into MSP which will be useful in pharmaceutical formulation development.

scholarly journals Preparation and Physicochemical Characterization of Water-Soluble Pyrazole-Based Nanoparticles by Dendrimer Encapsulation of an Insoluble Bioactive Pyrazole Derivative

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2662
Author(s):  
Silvana Alfei ◽  
Chiara Brullo ◽  
Debora Caviglia ◽  
Guendalina Zuccari
Keyword(s):  
Clinical Application ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Biological Activities ◽  
Drug Loading ◽  
Physicochemical Characterization ◽  
Water Soluble ◽  
First Order Kinetics ◽  
Physical Entrapment ◽  
Nano Formulation

2-(4-Bromo-3,5-diphenyl-pyrazol-1-yl)-ethanol (BBB4) was synthetized and successfully evaluated concerning numerous biological activities, except for antimicrobial and cytotoxic effects. Due to the antimicrobial effects possessed by pyrazole nucleus, which have been widely reported, and the worldwide need for new antimicrobial agents, we thought it would be interesting to test BBB4 and to evaluate its possible antibacterial effects. Nevertheless, since it is water-insoluble, the future clinical application of BBB4 will remain utopic unless water-soluble BBB4 formulations are developed. To this end, before implementing biological evaluations, BBB4 was herein re-synthetized and characterized, and a new water-soluble BBB4-based nano-formulation was developed by its physical entrapment in a biodegradable non-cytotoxic cationic dendrimer (G4K), without recovering harmful solvents as DMSO or surfactants. The obtained BBB4 nanoparticles (BBB4-G4K NPs) showed good drug loading (DL%), satisfying encapsulation efficiency (EE%), and a biphasic quantitative release profile governed by first-order kinetics after 24 h. Additionally, BBB4-G4K was characterized by ATR-FTIR spectroscopy, NMR, SEM, dynamic light scattering analysis (DLS), and potentiometric titration experiments. While, before the nanotechnological manipulation, BBB4 was completely water-insoluble, in the form of BBB4-G4K NPs, its water-solubility resulted in being 105-fold higher than that of the pristine form, thus establishing the feasibility of its clinical application.

scholarly journals Broad-Spectrum Bactericidal Activity of a Synthetic Random Copolymer Based on 2-Methoxy-6-(4-Vinylbenzyloxy)-Benzylammonium Hydrochloride

2021 ◽  
Vol 22 (9) ◽  
pp. 5021
Author(s):  
Anna Maria Schito ◽  
Gabriela Piatti ◽  
Debora Caviglia ◽  
Guendalina Zuccari ◽  
Silvana Alfei
Keyword(s):  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Random Copolymer ◽  
Multidrug Resistant ◽  
Water Soluble ◽  
Ammonium Salts ◽  
Gram Negative ◽  
Minimal Inhibitory Concentrations ◽  
Bacterial Membranes ◽  
Different Strains

Low-molecular-weight organic ammonium salts exert excellent antimicrobial effects by interacting lethally with bacterial membranes. Unfortunately, short-term functionality and high toxicity limit their clinical application. On the contrary, the equivalent macromolecular ammonium salts, derived from the polymerization of monomeric ammonium salts, have demonstrated improved antibacterial potency, a lower tendency to develop resistance, higher stability, long-term activity, and reduced toxicity. A water-soluble non-quaternary copolymeric ammonium salt (P7) was herein synthetized by copolymerizing 2-methoxy-6-(4-vinylbenzyloxy)-benzylammonium hydrochloride monomer with N, N-di-methyl-acrylamide. The antibacterial activity of P7 was assessed against several multidrug-resistant (MDR) clinical isolates of both Gram-positive and Gram-negative species. Except for colistin-resistant Pseudomonas aeruginosa, most isolates were susceptible to P7, also including some Gram-negative bacteria with a modified charge in the external membrane. P7 showed remarkable antibacterial activity against isolates of Enterococcus, Staphylococcus, Acinetobacter, and Pseudomonas, and on different strains of Escherichia coli and Stenotrophomonas maltophylia, regardless of their antibiotic resistance. The lowest minimal inhibitory concentrations (MICs) observed were 0.6–1.2 µM and the minimal bactericidal concentrations (MBC) were frequently overlapping with the MICs. In 24-h time–kill and turbidimetric studies, P7 displayed a rapid non-lytic bactericidal activity. P7 could therefore represent a novel and potent tool capable of counteracting infections sustained by several bacteria that are resistant to the presently available antibiotics.

scholarly journals Use of Lemongrass Leaf Ethanol Extract for Developing Alginate Based Antibacterial Edible Films

2020 ◽  
Vol 10 (2) ◽  
pp. 99-107
Keyword(s):  
Antibacterial Activity ◽  
Moisture Content ◽  
Food Packaging ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Brown Seaweed ◽  
Ethanol Extract ◽  
Edible Films ◽  
Edible Film ◽  
Alcohol Extract

Alginates extracted from brown seaweed have a variety of prospective applications such as thickeners, stabilizers, or restructuring agents. Due to its properties as a natural polysaccharide, alginate is very potential to be used as edible films for food packaging purposes. Edible films are developed for food protection being excellent barriers to gases but not to moisture. Incorporation of antimicrobial agents into edible film formulation can extend product shelf life and reduce the risk of pathogenic bacterial growth on food. Therefore, this study was aimed to develop an alginate based antibacterial edible film. Antibacterial agent extracted from lemongrass leaves using ethanol was employed. The study was conducted by varying the addition levels of lemongrass ethanol extract to the alginate based edible films, i.e. 0.5%, 1.0% and 1.5%. Before being added to the alginate based edible films, the lemongrass ethanol extract was investigated for its antibacterial activity. The edible films obtained were analyzed in terms of physical, mechanical and chemical and microbiological parameters, including thickness, water vapor transmission rate (WVTR), brightness, tensile strength, elongation, moisture content, water solubility and antibacterial activity. Results showed that the higher addition levels of lemongrass ethanol extract tended to produce alginate based edible films with lower WVTR and brightness value as well as higher elongation, moisture content and water solubility. Edible film added with lemongrass ethanol extract resulted in this study demonstrated antibacterial activity against Staphylococcus aureus. The addition of lemongrass alcohol extract at 0.5% was considered as a recommended concentration level for producing alginate based antibacterial edible films.

scholarly journals Considerable Improvement of Ursolic Acid Water Solubility by Its Encapsulation in Dendrimer Nanoparticles: Design, Synthesis and Physicochemical Characterization

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2196 ◽  
Author(s):  
Silvana Alfei ◽  
Anna Maria Schito ◽  
Guendalina Zuccari
Keyword(s):  
Ursolic Acid ◽  
Water Solubility ◽  
Drug Loading ◽  
Physicochemical Characterization ◽  
Systemic Toxicity ◽  
Water Soluble ◽  
Design Synthesis ◽  
Pentacyclic Triterpenoid

Ursolic acid (UA) is a pentacyclic triterpenoid found in many medicinal plants and aromas endowed with numerous in vitro pharmacological activities, including antibacterial effects. Unfortunately, UA is poorly administered in vivo, due to its water insolubility, low bioavailability, and residual systemic toxicity, thus making urgent the development of water-soluble UA formulations. Dendrimers are nonpareil macromolecules possessing highly controlled size, shape, and architecture. In dendrimers with cationic surface, the contemporary presence of inner cavities and of hydrophilic peripheral functions, allows to encapsulate hydrophobic non-water-soluble drugs as UA, to enhance their water-solubility and stability, and to promote their protracted release, thus decreasing their systemic toxicity. In this paper, aiming at developing a new UA-based antibacterial agent administrable in vivo, we reported the physical entrapment of UA in a biodegradable not cytotoxic cationic dendrimer (G4K). UA-loaded dendrimer nanoparticles (UA-G4K) were obtained, which showed a drug loading (DL%) much higher than those previously reported, a protracted release profile governed by diffusion mechanisms, and no cytotoxicity. Also, UA-G4K was characterized by principal components analysis (PCA)-processed FTIR spectroscopy, by NMR and elemental analyses, and by dynamic light scattering experiments (DLS). The water solubility of UA-G4K was found to be 1868-fold times higher than that of pristine UA, thus making its clinical application feasible.

scholarly journals Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan

2010 ◽  
Vol 53 (3) ◽  
pp. 623-628 ◽  
Author(s):  
Hortensia Ortega-Ortiz ◽  
Baltazar Gutiérrez-Rodríguez ◽  
Gregorio Cadenas-Pliego ◽  
Luis Ibarra Jimenez
Keyword(s):  
Antibacterial Activity ◽  
Acrylic Acid ◽  
Antimicrobial Agents ◽  
Water Soluble ◽  
Amino Groups ◽  
Molecular Weights ◽  
Carboxylic Acid Groups ◽  
Microbial Inhibition ◽  
Interpolyelectrolyte Complexes ◽  
Poly Acrylic Acid

The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition φ =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid).

scholarly journals Total Phenolic Content and Antibacterial Activity of Nut Grass (Cyperus rotundus L.) Extract

2018 ◽  
Vol 1 (1) ◽  
pp. 28-36
Author(s):  
Masfria ◽  
Yade Metri Permata
Keyword(s):  
Antibacterial Activity ◽  
Ethyl Acetate ◽  
Staphylococcus Epidermidis ◽  
Raw Materials ◽  
Water Soluble ◽  
Cyperus Rotundus ◽  
Shigella Dysenteriae ◽  
Total Polyphenol ◽  
Ethanol Extracts

Abstract. The objectives of this research was to study the macroscopic, the microscopic and phytochemicals characterization of raw materials, total polyphenol content and the antibacterial activity of nut grass extracts (Cyperus rotundus L.) against Shigella dysenteriae, Salmonella typhimurium, Staphylococcus epidermidis, and Pseudomonas aeroginosa.  The macroscopic and the microscopic characterization of raw materials were done with the determination of the water contents, the water soluble contents, the ethanol soluble contents, total ash and acid soluble ash. The extract was prepared by percolation using n-hexane, ethanol, and ethyl acetate as solvents. Phytochemical screening was done on the raw materials as well as n-hexane, ethyl acetate, and ethanol extracts. Total phenol contents were tested with the Folin-Ciocalteu reagent method. The antibacterial activity test was done by measuring the diameter of the inhibition zones using the diffusion agar method.  The results showed that raw material retrieved 7.33% water content, 21.85% water soluble contents, 7.9% ethanol soluble contents, 1.53% total ash, and 0.67% total insoluble-acid ash. The phytochemical study showed that the nut grass contains various secondary metabolites including flavonoids, glycosides, saponins, anthraquinone glycosides, and steroid/triterpenoids. The total polyphenol contents of ethanol extracts were expressed as catechin equivalents 1.1616 mg/g extract.  All of the nut grass extract showed antibacterial activity. Ethyl acetate extract of nut grass indicated the highest antibacterial activity against Shigella dysenteriae, Salmonella typhimurium, and Pseudomonas aeroginosa. Ethanol extract was only effective against Staphylococcus epidermidis.   Keywords: Antibacterial Activity, Bacteria, Cyperus Rotundus L Extracts, Phenolic

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