scholarly journals Ciprofloxacin-Releasing ROS-Sensitive Nanoparticles Composed of Poly(Ethylene Glycol)/Poly(D,L-lactide-co-glycolide) for Antibacterial Treatment

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4125
Author(s):  
Jaeik Song ◽  
Min-Suk Kook ◽  
Byung-Hoon Kim ◽  
Young-IL Jeong ◽  
Kyung-Jin Oh

Since urinary tract infections (UTIs) are closely associated with oxidative stress, we developed ROS-sensitive nanoparticles for ciprofloxacin (CIP) delivery for inhibition of UTI. Poly(D,L-lactide-co-glycolide) (PLGA)- selenocystamine (PLGA-selenocystamine) conjugates were attached to methoxypoly(ethylene glycol) (PEG) tetraacid (TA) (TA-PEG) conjugates to produce a copolymer (abbreviated as LGseseTAPEG). Selenocystamine linkages were introduced between PLGA and TA to endow reactive oxygen species (ROS) sensitivity to nanoparticles. CIP-incorporated nanoparticles of LGseseTAPEG copolymer were fabricated by W/O/W/W emulsion method. CIP-incorporated nanoparticles responded to H2O2 and then their morphologies were disintegrated by incubation with H2O2. Furthermore, particle size distribution of nanoparticles was changed from mono-modal distribution pattern to multi-modal distribution pattern by addition of H2O2. CIP release from nanoparticles of LGseseTAPEG copolymer was faster in the presence of H2O2 than in the absence of it. In antibacterial study using Escherichia coli (E. coli), free CIP and free CIP plus empty nanoparticles showed dose-dependent inhibitory effect against growth of bacteria while CIP-incorporated nanoparticles have less antibacterial activity compared to free CIP. These results were due to that CIP-incorporated nanoparticles have sustained release properties. When free CIP or CIP-incorporated nanoparticles were introduced into dialysis membrane to mimic in vivo situation, CIP-incorporated nanoparticles showed superior antibacterial activity compared to free CIP. At cell viability assay, nanoparticles of LGseseTAPEG copolymer have no acute cytotoxicity against L929 mouse fibroblast cells and CCD986sk human skin fibroblast cells. We suggest LGseseTAPEG nanoparticles are a promising candidate for CIP delivery.

2021 ◽  
Vol 25 (1) ◽  
pp. 43-46
Author(s):  
Taofeeq Garuba ◽  
Nency Katrodiya ◽  
Nikita Patel ◽  
Swetal Patel ◽  
Dhanji. P. Rajani ◽  
...  

Urinary tract infections (UTI) are one of the most common form of bacterial infections but the treatment becomes cumbersome as the etiological bacteria are developing resistance against antibiotics. This present study evaluated the efficacy of antimicrobial   activity of Urena lobata against uropathogens. Six urine samples from UTI patients were collected from Pathological Laboratory, G.B. Vaghani Multispecialty Hospital, Surat. Bacteria were isolated from these samples using Nutrient agar, Mac Conkey agar plate, Blood agar, Mannitol salt agar, Eosin Methylene Blue agar and King’s agar. The bacterial isolates were identified using cultural  characteristics, microscopic features and biochemical characteristics. Leaf extract of Urena lobata was prepared using Soxhlet Extraction Method whereby methanol and distilled water were the extractants used. Herbal extract disc was prepared at  concentrations of 50,75, and100 mg/ml and tested against all the isolates. DMSO and antibiotics (Nitrofurantion, Amikacin, Levofloxacin, Norofloxacin, Ofloxacin and Cephalosporins) were used as negative and positive controls respectively.Staphylococcus aureus, Escherichia coli, Bacillus cereus, Streptococcus pneumoniae, Klebsiella spp. and Brevibacillus panacihumi were isolated from the urine samples. All concentrations of aqueous and methanolic extracts of U. lobata leaf displayed highest zone of inhibition against B. cereus. No inhibitory effect was observed against the growth of Klebsiella except at the highest concentrations. Further study is encouraged on the in-vivo study of efficacy of U. lobata on etiological agent of UTI.


2020 ◽  
Author(s):  
Shijun Su ◽  
Mei Chen ◽  
Xuemei Tang ◽  
Feng Peng ◽  
Tingting Liu ◽  
...  

Abstract A series of pyrimidine-containing 4H-chromen-4-one derivatives were designed and synthesized by combining bioactive substructures. All compounds were characterized using 1H NMR, 13C NMR, 19F NMR and HRMS. Preliminary biological activity results showed that most of title compounds displayed significant inhibitory activity against Xanthomonas axonopodis pv. Citri (Xac), Xanthomonas oryzae pv. oryzae (Xoo) and Ralstonia solanacearum (Rs). In particular, compound 4c demonstrated a good inhibitory effect against Xac and Xoo, with half-maximal effective concentration(EC50) values of 15.5 and 14.9 μg/mL respectively, and that of compound 4h showed the best antibacterial activity against Rs with an EC50 value of 14.7 μg/mL, These results were better than both bismerthiazol (BT, 51.7, 70.1 and 52.7 μg/mL, respectively) and thiodiazole copper (TC, 77.9, 95.8 and 72.1 μg/mL respectively). In vivo antibacterial activity results indicated that compound 4c displayed better curative(42.4%) and protective (49.2%) activities for reducing rice bacterial leaf blight than both BT (35.2, 39.1%) and TC (30.8, 27.3%). The mechanism of compound 4c against Xoo was analysed through scanning electron microscopy (SEM). Results showed that the compound destroied the bacterial cell membrane structure. These results indicated that pyrimidine-containing 4H-chromen-4-one derivatives are valuable in the research of new agrochemicals.


Author(s):  
N. Ramalakshmi ◽  
S.R. Chitra ◽  
P. Manimegalai ◽  
S. Arunkumar

Background: Hospital acquired (HA) infections are caused due to E. coliwhich is resistant to multiple drugs particularly to fluroquinolone class of drugs. Urinary tract infections (UTI) affects people in the community and in hospitals. 150 million people per annum are suffering from UTI worldwide. Methods: In this present study we designed 36 novel coumarin derivatives, also we predicted pharmacokinetic and toxicity parameters. Docking studies were also carriedand all the compounds were evaluated for antibacterial activity againstresistant quinolone E. coli strain ATCC 25922. It was interesting to note thatthe introduction of electron withdrawing group on the aromatic ringresulted in compounds with increased antibacterial activity which is observed in compound 6 (with4-nitro substitution), compound 23(chloro) and compound 30(chloro, nitro). Results: From the MIC results, was observed that compounds 6, 23 and 30 showed higher activity with 0.5µg/ml, 0. 12 µg/ml, 0.5 µg/mlrespectively. Docking studies were performed with the activesite of DNA gyrase (PDB ID: 4CKK ).The maximum binding energy was found to be -10.7Kcal/mol. Conclusion: From the study it was found that 3 compounds were potentially active against quinolone resistant E. coli strains. This study can be further extended for in vivo evaluation.


Author(s):  
Vahideh Hasabi ◽  
Hossein Askari ◽  
Seyed Mehdi Alavi ◽  
Masood Soltani Najafabadi

Asiatic citrus canker caused by Xanthomonas citri subsp. citri is becoming a disease of high economic impact, affecting all types of important citrus crops. In this study, the potential antibacterial activity of ten organic and inorganic salts on X. citri subsp. citri and on citrus canker disease development was evaluated. Among the salt compounds, copper, iron and zinc inorganic salts particularly zinc (with the highest diameter of inhibition, the lowest MIC and MBC values and the highest bacterial growth inhibitory effect) had direct antibacterial activity and strongly reduced the development of canker disease and bacterial population of lime plants.


Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1185
Author(s):  
Sang-Hun Oh ◽  
Young-Rok Kim ◽  
Hee-Soo Park ◽  
Kyu-Man Oh ◽  
Young-Lag Cho ◽  
...  

Klebsiella pneumoniae is one of the important clinical organisms that causes various infectious diseases, including urinary tract infections, necrotizing pneumonia, and surgical wound infections. The increase in the incidence of multidrug-resistance K. pneumoniae is a major problem in public healthcare. Therefore, a novel antibacterial agent is needed to treat this pathogen. Here, we studied the in vitro and in vivo activities of a novel antibiotic LCB10-0200, a siderophore-conjugated cephalosporin, against clinical isolates of K. pneumoniae. In vitro susceptibility study found that LCB10-0200 showed potent antibacterial activity against K. pneumoniae, including the beta-lactamase producing strains. The in vivo efficacy of LCB10-0200 was examined in three different mouse infection models, including systemic, thigh, and urinary tract infections. LCB10-0200 showed more potent in vivo activity than ceftazidime in the three in vivo models against the drug-susceptible and drug-resistant K. pneumoniae strains. Taken together, these results show that LCB10-0200 is a potential antibacterial agent to treat infection caused by K. pneumoniae.


Author(s):  
Amal Talib Al-Sa'ady

200 different clinical samples were collected from patients with Burns infections, wound infections, urinary Tract Infections & diarrhea for a period from March to August, 2017. Total of 403 bacterial isolates were identified, the gram negative bacteria E.coli represented329 (48.9%). The percentages of E.coliisolatesare different depending on isolation sources, urinary Tract Infections have the highest rate of isolation (72.2%). Bacterial sensitivity against10different antibiotics were tested, all isolates showed full resistance againstPenicillins & Cephalosporins while they have high sensitivity for Nitrofurantion. The other antibiotics have different effects depending on the isolation sources. Natural Honey has high antibacterial activity for E.coliwithout any influence withisolation sources with MIC,15%. Antibacterial activity ofthe EthanolicExtracts (95%) for four plants: Allium sativum,Paganum harmala,Nigella sativum & Myrtus communs. All of this have high inhibitory effect onE.coliisolates without any influence of the isolation sources, but Allium sativum extract has the highest effect with inhibition zone diameters (20.1-32.0) mm.


2019 ◽  
Vol 33 (10) ◽  
pp. 1415-1426
Author(s):  
Rashed Almouse ◽  
Xin Wen ◽  
Sungsoo Na ◽  
Gregory Anderson ◽  
Dong Xie

This study reports synthesis and attachment of a novel antibacterial and hydrophilic polymer onto a polyvinylchloride surface via a simple and mild surface coating technique. The compound 3,4-dichloro-5-hydroxy-2(5H)-furanone was derivatized and copolymerized with N-vinylpyrrolidone. The copolymer was then covalently coated onto polyvinylchloride surface. 3T3 mouse fibroblast cells and bacterium Pseudomonas aeruginosa were used to evaluate surface adhesion and antibacterial activity. Results showed that the polymer-modified polyvinylchloride surface not only exhibited significantly decreased 3T3 fibroblast cell adhesion with a 64–84% reduction but also demonstrated significantly decreased P. aeruginosa adhesion with a 65–84% reduction, as compared to unmodified polyvinylchloride. Furthermore, the modified polyvinylchloride surfaces exhibited significant antibacterial functions by inhibiting P. aeruginosa growth with a 58–80% reduction and killing bacteria, as compared to unmodified polyvinylchloride. These results demonstrate that covalent polymer attachment conferred cell/bacterial adhesion-resistant and antibacterial properties to the polyvinylchloride surface.


Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1488
Author(s):  
Lei Wang ◽  
Xia Zhou ◽  
Hui Lu ◽  
Xianfu Mu ◽  
Linhong Jin

In order to discover new lead compounds with high antibacterial activity, a series of new derivatives were designed and synthesized by introducing a sulfonate or carboxylate moiety into the 1,3,4-oxadiazole structure. Antibacterial activity against two phytopathogens, Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas axonopodis pv. citri (Xac), was assayed in vitro. The preliminary results indicated that ten compounds including 4a-1-4a-4 and 4a-11-4a-16 had good antibacterial activity against Xoo, with EC50 values ranging from 50.1-112.5 µM, which was better than those of Bismerthiazol (253.5 µM) and Thiodiazole copper (467.4 µM). Meanwhile, 4a-1, 4a-2, 4a-3 and 4a-4 demonstrated good inhibitory effect against Xanthomonas axonopodis pv. citri with EC50 values around 95.8-155.2 µM which were better than those of bismerthiazol (274.3 µM) and thiodiazole copper (406.3 µM). In addition, in vivo protection activity of compound 4a-2 and 4a-3 against rice bacterial leaf blight was 68.6% and 62.3%, respectively, which were better than bismerthiazol (49.6%) and thiodiazole copper (42.2%). Curative activity of compound 4a-2 and 4a-3 against rice bacterial leaf blight was 62.3% and 56.0%, which were better than bismerthiazol (42.9%) and thiodiazole copper (36.1%). Through scanning electron microscopy (SEM) analysis, it was observed that compound 4a-2 caused the cell membrane of Xanthomonas oryzae pv. oryzae ruptured or deformed. The present results indicated novel derivatives of 5-phenyl sulfonate methyl 1,3,4-oxadiazole might be potential antibacterial agents.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 417-431 ◽  
Author(s):  
A. du P Heyns ◽  
D. J van den Berg ◽  
G. M Potgieter ◽  
F. P Retief

SummaryThe platelet aggregating activity of extracts of different layers of the arterial wall was compared to that of Achilles tendon. Arterial media and tendon extracts, adjusted to equivalent protein content as an index of concentration, aggregated platelets to the same extent but an arterial intima extract did not aggregate platelets. Platelet aggregation induced by collagen could be inhibited by mixing with intima extract, but only to a maximum of about 80%. Pre-mixing adenosine diphosphate (ADP) with intima extracts diminished the platelet aggregation activity of the ADP. Depending on the relationship between ADP and intima extract concentrations aggregating activity could either be completely inhibited or inhibition abolished. Incubation of ADP with intima extract and subsequent separation of degradation products by paper chromatography, demonstrated a time-dependent breakdown of ADP with AMP, adenosine, inosine and hypoxanthine as metabolic products; ADP removal was complete. Collagen, thrombin and adrenaline aggregate platelets mainly by endogenous ADP of the release reaction. Results of experiments comparing inhibition of aggregation caused by premixing aggregating agent with intima extract, before exposure to platelets, and the sequential addition of first the intima extract and then aggregating agent to platelets, suggest that the inhibitory effect of intima extract results from ADP breakdown. It is suggested that this ADP degradation by intima extract may play a protective role in vivo by limiting the size of platelet aggregates forming at the site of minimal “wear and tear” vascular trauma.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 704-713 ◽  
Author(s):  
F. N McKenzie ◽  
K.-E Arfors ◽  
N. A Matheson

SummaryA study has been made of the biochemical factors underlying the platelet response to laser-induced microvascular injury. A platelet aggregating substance is produced at sites of laser-induced injury which markedly stimulates platelet activity at a site of injury inflicted a short distance downstream. Distal sites of injury are not similarly influenced if the distance between the injuries is increased or if the proximal site no longer shows platelet-stimulating activity. The stimulating effect of an adjacent proximal injury on platelet activity at a distal site is inhibited by local intra-arterial infusion of adenosine. Measurements of arterial blood pressure and microvascular blood flow velocity during adenosine infusion showed that its inhibitory effect on platelet activity is largely independent of its vasodilator properties. The effect of infusion of different adenosine phosphates (AMP, ADP, ATP) was also studied. Very small amounts of ADP markedly stimulated platelet activity and the emboli formed were similar to those normally produced at sites of laser injury. At high concentration AMP inhibited while ATP stimulated platelet activity in vivo. The results emphasise the fundamental role of ADP as a mediator of the platelet response at sites of laser- induced microvascular injury.


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