Encapsulation in fusogenic liposomes broadens the spectrum of action of vancomycin against Gram-negative bacteria

Nicolosi, Daria; Scalia, Marina; Nicolosi, V.M.; Pignatello, Rosario

doi:10.1016/j.ijantimicag.2010.01.015

Cited by 119 publications

(117 citation statements)

References 39 publications

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“…Due to their large size and hydrophobicity, glycopeptides are not effective against Gram-negative bacteria. It has been reported that encapsulation in fusogenic liposomes could broaden the spectrum of action of vancomycin against Gram-negative bacteria 18 . The cellpermeabilizing properties of colistin could be exploited to improve the penetration of glycopeptides through the OM of A. baumannii toward their targets in the cell wall 19 .…”

Section: Discussionmentioning

confidence: 99%

Colistin and anti-Gram-positive bacterial agents against Acinetobacter baumannii

Liu

et al. 2014

Rev. Soc. Bras. Med. Trop.

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Introduction:Acinetobacter baumannii has attained an alarming level of resistance to antibacterial drugs. Clinicians are now considering the use of older agents or unorthodox combinations of licensed drugs against multidrug-resistant strains to bridge the current treatment gap. We investigated the in vitro activities of combination treatments that included colistin with vancomycin, norvancomycin or linezolid against multidrug-resistant Acinetobacter baumannii. Methods: The fractional inhibitory concentration index and time-kill assays were used to explore the combined effects of colistin with vancomycin, norvancomycin or linezolid against 40 clinical isolates of multidrug-resistant Acinetobacter baumannii. Transmission electron microscopy was performed to evaluate the interactions in response to the combination of colistin and vancomycin. Results: The minimum inhibitory concentrations (MICs) of vancomycin and norvancomycin for half of the isolates decreased below the susceptibility break point, and the MIC of linezolid for one isolate was decreased to the blood and epithelial lining fl uid concentration using the current dosing regimen. When vancomycin or norvancomycin was combined with subinhibitory doses of colistin, the multidrug-resistant Acinetobacter baumannii test samples were eradicated. Transmission electron microscopy revealed that subinhibitory doses of colistin were able to disrupt the outer membrane, facilitating a disruption of the cell wall and leading to cell lysis. Conclusions: Subinhibitory doses of colistin signifi cantly enhanced the antibacterial activity of vancomycin, norvancomycin, and linezolid against multidrug-resistant Acinetobacter baumannii.

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Section: Discussionmentioning

confidence: 99%

Colistin and anti-Gram-positive bacterial agents against Acinetobacter baumannii

Liu

et al. 2014

Rev. Soc. Bras. Med. Trop.

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“…Liposomes containing a phosphoethanolamine (PE) moiety such as 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) are well-known examples. [24][25][26] The fluidity of liposomes can be tuned by the choice of phospholipids. In general, the shorter the acyl chains of the phospholipids, the lower the phase transition temperature (Tc) of the liposomes will be.…”

Section: Fusogenic Liposomesmentioning

confidence: 99%

“…Electron microscopy images confirmed the interaction and possible fusion of the fusogenic liposomes with the outer membrane of E. coli cells. [25] The fluidity of the liposomal membrane also has an influence on the transport of the liposomal formulation to the site of infection. For example, flexible daptomycin-containing liposomes composed of soy phosphatidylcholine and sodium cholate were found to rapidly distribute in skin tissue, making them suitable for anti-biofilm topical skin therapy.…”

Section: Fusogenic Liposomesmentioning

confidence: 99%

Lipid and polymer nanoparticles for drug delivery to bacterial biofilms

Forier

Raemdonck

Smedt

et al. 2014

Journal of Controlled Release

372

320

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Biofilms are matrix-enclosed communities of bacteria that show increased antibiotic resistance and the capability to evade the immune system. They can cause recalcitrant infections which cannot be cured with classical antibiotic therapy. Drug delivery by lipid or polymer nanoparticles is considered a promising strategy for overcoming biofilm resistance. These particles are able to improve the delivery of antibiotics to the bacterial cells, thereby increasing the efficacy of the treatment. In this review we give an overview of the types of polymer and lipid nanoparticles that have been developed for this purpose. The antimicrobial activity of nanoparticle encapsulated antibiotics compared to the activity of the free antibiotic is discussed in detail. In addition, targeting and triggered drug release strategies to further improve the antimicrobial activity are reviewed. Finally, ample attention is given to advanced microscopy methods that shed light on the behavior of nanoparticles inside biofilms, allowing further optimization of the nanoformulations. Lipid and polymer nanoparticles were found to increase the antimicrobial efficacy in many cases. Strategies such as the use of fusogenic liposomes, targeting of the nanoparticles and triggered release of the antimicrobial agent ensured the delivery of the antimicrobial agent in close proximity of the bacterial cells, maximizing the exposure of the biofilm to the antimicrobial agent. The majority of the discussed papers still present data on the in vitro anti-biofilm activity of nanoformulations, indicating that there is an urgent need for more in vivo studies in this field.

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“…The fluidity of the liposomes can be achieved by lowering the phase transition temperature, by incorporation of components of the inactivated Sendai virus envelope, using lipids which have the phosphatidylethanolamine moiety, lipids with double bonds and/or asymmetry in acyl chain, or by addition of cholesterol [184,[216][217][218][219][220]. Antibiotics enter Gram-negative bacteria by two routes: hydrophobic drugs enter by passive transport via the lipopolysaccharide and proteinrich outer membrane; whereas hydrophilic drugs enter through the outer membrane water-filled porin channels.…”

Section: Non-specific Targetingmentioning

confidence: 99%

A New Era of Pulmonary Delivery of Nano-antimicrobial Therapeutics to Treat Chronic Pulmonary Infections

Merchant

Buckton²,

Taylor³

et al. 2016

CPD

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Pulmonary infections may be fatal especially in immunocompromised patients and patients with underlying pulmonary dysfunction, such as those with cystic fibrosis, chronic obstructive pulmonary disorder, etc. According to the WHO, lower respiratory tract infections ranked first amongst the leading causes of death in 2012, and tuberculosis was included in the top 10 causes of death in low income countries, placing a considerable strain on their economies and healthcare systems. Eradication of lower respiratory infections is arduous, leading to high healthcare costs and requiring higher doses of antibiotics to reach optimal concentrations at the site of pulmonary infection for protracted periods. Hence direct inhalation to the respiratory epithelium has been investigated extensively in the past decade, and seems to be an attractive approach to eradicate and hence overcome this widespread problem. Moreover, engineering inhalation formulations wherein the antibiotics are encapsulated within nanoscale carriers could serve to overcome many of the limitations faced by conventional antibiotics, like difficulty in treating intracellular pathogens such as mycobacteria spp. and salmonella spp., biofilmassociated pathogens like Pseudomonas aeruginosa and Staphylococcus aureus, passage through the sputum associated with disorders like cystic fibrosis and chronic obstructive pulmonary disorder, systemic side effects following oral/parenteral delivery and inadequate concentrations of antibiotic at the site of infection leading to resistance. Encapsulation of antibiotics in nanocarriers may help in providing a protective environment to combat antibiotic degradation, confer controlled-release properties, hence reducing dosing frequency, and may increase uptake via specific and non-specific targeting modalities. Hence nanotechnology combined with direct administration to the airways using commercially available delivery devices, is a highly attractive formulation strategy to eradicate microorganisms from the lower respiratory tract, which might otherwise present opportunities for multi-drug resistance.

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Encapsulation in fusogenic liposomes broadens the spectrum of action of vancomycin against Gram-negative bacteria

Cited by 119 publications

References 39 publications

Colistin and anti-Gram-positive bacterial agents against Acinetobacter baumannii

Colistin and anti-Gram-positive bacterial agents against Acinetobacter baumannii

Lipid and polymer nanoparticles for drug delivery to bacterial biofilms

A New Era of Pulmonary Delivery of Nano-antimicrobial Therapeutics to Treat Chronic Pulmonary Infections

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