Antimicrobial applications of nanoliposome encapsulated silver nanoparticles: a potential strategy to overcome bacterial resistance

: Bacterial infections result in hundreds of million cases of severe illness annually worldwide. Rapidly increasing drug resistance of pathogens further aggravates this threat to human health and warrants the search for effective broadspectrum antibacterial agents. Silver metal has a long history of application in human medicine and healthcare. In ancient times, silver was employed as a disinfectant for water purification and storage while it is still being used as an antimicrobial ingredient in some nanotechnology-based products. Encapsulation of antimicrobial substances such as silver nanoparticles in nanoliposomes could provide protection and targeting for the encapsulated or entrapped material. Nanoliposomes are biocompatible and biodegradable drug delivery systems with the ability to encapsulate both lipidsoluble and water-soluble compounds, as well as metal ions. Furthermore, nanoliposomes have been shown to be able to deliver encapsulated agents to target bacteria in vitro as well as in vivo. In this review, we present the use of nanoliposome-encapsulated silver nanoparticles as an efficient system for antibacterial applications.

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A Review of the Combination Therapy of Low Frequency Ultrasound with Antibiotics

BioMed Research International ◽

10.1155/2017/2317846 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 13

Author(s):

Yun Cai ◽

Jin Wang ◽

Xu Liu ◽

Rui Wang ◽

Lei Xia

Keyword(s):

Combination Therapy ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Low Frequency ◽

Bactericidal Effect ◽

Low Frequency Ultrasound ◽

Biofilm Bacteria ◽

Frequency Ultrasound

Single antimicrobial therapy has been unable to resist the global spread of bacterial resistance. Literatures of availablein vitroandin vivostudies were reviewed and the results showed that low frequency ultrasound (LFU) has a promising synergistic bactericidal effect with antibiotics against both planktonic and biofilm bacteria. It also can facilitate the release of antibiotics from medical implants. As a noninvasive and targeted therapy, LFU has great potential in treating bacterial infections. However, more in-depth and detailed studies are still needed before LFU is officially applied as a combination therapy in the field of anti-infective treatment.

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In Vitro and In Vivo Antitumor Activity of Silver Nanoparticles on B16 Melanoma

NANO ◽

10.1142/s1793292020501635 ◽

2020 ◽

Vol 15 (12) ◽

pp. 2050163

Author(s):

Hongkun Gao ◽

Ping Fan ◽

Qizhen Xu ◽

Yiting Li ◽

Jianxin Wang ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antitumor Activity ◽

Antimicrobial Agents ◽

Malignant Tumors ◽

Annexin V ◽

In Vitro Study ◽

B16 Melanoma ◽

Potential Strategy

Melanoma, one of the most malignant tumors, is difficult to treat due to its high drug resistance. Silver nanoparticles (AgNPs) are widely used as antimicrobial agents in biomedical fields. In this study, the spherical AgNPs with average sizes of 5[Formula: see text]nm were prepared using a dopamine reduction method. The in vitro study shows that AgNPs with the concentrations of 0.5[Formula: see text][Formula: see text]g/mL and 1[Formula: see text][Formula: see text]g/mL exhibit good biocompatibility to 3T3L1 fibroblast cells. AgNPs with the same concentrations significantly inhibited the growth of B16 melanoma cells. In culture with B16 cells, AgNPs induced intracellular oxidative stress by generating the reactive oxygen species and reducing the superoxide dismutase, which further reduces the mitochondrial membrane potential. Moreover, the damage in mitochondria could activate mitochondrion-mediated cell apoptosis. The B16 cells apoptosis was analyzed by FITC-Annexin V/propidium iodide double staining assay, which confirms that AgNPs caused the abundance of apoptotic cells in different stages. Thus, AgNPs displayed the antitumor activity in vitro. Then, the therapeutic efficacy in vivo was evaluated in mice-bearing B16 melanoma tumors. The obtained results show the antitumor ability of AgNPs and provide a potential strategy for cancer treatment.

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Detection of Quorum-Sensing Molecules for Pathogenic Molecules Using Cell-Based and Cell-Free Biosensors

Antibiotics ◽

10.3390/antibiotics9050259 ◽

2020 ◽

Vol 9 (5) ◽

pp. 259 ◽

Cited By ~ 1

Author(s):

Craig Miller ◽

Jordon Gilmore

Keyword(s):

Quorum Sensing ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Genetic Material ◽

Treatment Strategies ◽

Signaling Molecules ◽

Resistant Bacteria ◽

Acute Infections

Since the discovery and subsequent use of penicillin, antibiotics have been used to treat most bacterial infections in the U.S. Over time, the repeated prescription of many antibiotics has given rise to many antibiotic-resistant microbes. A bacterial strain becomes resistant by horizontal gene transfer, where surviving microbes acquire genetic material or DNA fragments from adjacent bacteria that encode for resistance. In order to avoid significant bacterial resistance, novel and target therapeutics are needed. Further advancement of diagnostic technologies could be used to develop novel treatment strategies. The use of biosensors to detect quorum-sensing signaling molecules has the potential to provide timely diagnostic information toward mitigating the multidrug-resistant bacteria epidemic. Resistance and pathogenesis are controlled by quorum-sensing (QS) circuits. QS systems secrete or passively release signaling molecules when the bacterial concentration reaches a certain threshold. Signaling molecules give an early indication of virulence. Detection of these compounds in vitro or in vivo can be used to identify the onset of infection. Whole-cell and cell-free biosensors have been developed to detect quorum-sensing signaling molecules. This review will give an overview of quorum networks in the most common pathogens found in chronic and acute infections. Additionally, the current state of research surrounding the detection of quorum-sensing molecules will be reviewed. Followed by a discussion of future works toward the advancement of technologies to quantify quorum signaling molecules in chronic and acute infections.

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Multiple Mechanisms of the Synthesized Antimicrobial Peptide TS against Gram-Negative Bacteria for High Efficacy Antibacterial Action In Vivo

Molecules ◽

10.3390/molecules26010060 ◽

2020 ◽

Vol 26 (1) ◽

pp. 60

Author(s):

Rui Zhang ◽

Xiaobo Fan ◽

Xinglu Jiang ◽

Mingyuan Zou ◽

Han Xiao ◽

...

Keyword(s):

Antimicrobial Peptide ◽

Bacterial Infections ◽

Bacterial Resistance ◽

Divalent Cations ◽

Resistant Bacteria ◽

Antibacterial Drug ◽

Gram Negative Bacteria ◽

Gram Negative

The emergence of drug-resistant bacteria emphasizes the urgent need for novel antibiotics. The antimicrobial peptide TS shows extensive antibacterial activity in vitro and in vivo, especially in gram-negative bacteria; however, its antibacterial mechanism is unclear. Here, we find that TS without hemolytic activity disrupts the integrity of the outer bacterial cell membrane by displacing divalent cations and competitively binding lipopolysaccharides. In addition, the antimicrobial peptide TS can inhibit and kill E. coli by disintegrating the bacteria from within by interacting with bacterial DNA. Thus, antimicrobial peptide TS’s multiple antibacterial mechanisms may not easily induce bacterial resistance, suggesting use as an antibacterial drug to be for combating bacterial infections in the future.

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Exploring the Antivirulence Activity of Pulverulentone A, a Phloroglucinol-Derivative from Callistemon citrinus Leaf Extract, against Multi-Drug Resistant Pseudomonas aeruginosa

Antibiotics ◽

10.3390/antibiotics10080907 ◽

2021 ◽

Vol 10 (8) ◽

pp. 907

Author(s):

Maha M. Ismail ◽

Mariam Hassan ◽

Sawsan S. Moawad ◽

Mona M. Okba ◽

Rehab M. Ashour ◽

...

Keyword(s):

In Silico ◽

Bacterial Infections ◽

Leaf Extract ◽

Extracellular Polymeric Substances ◽

Bacterial Resistance ◽

Galleria Mellonella ◽

Major Constituent ◽

In Silico Docking

(1) Background: Bacterial resistance to antibiotics is a global life-threatening issue. Antivirulence therapy is a promising approach to combat bacterial infections as it disarms the bacteria from their virulence factors with reduced selective pressure and a lower chance of resistance. (2) Methods: Callistemon citrinus leaf extract and its major constituent, Pulverulentone A, were tested for their ability to inhibit biofilm, exopolysaccharides, pyocyanin and proteases produced by MDR P. aeruginosa. In addition, a Galleria mellonella larvae model was employed to evaluate the in vivo cytotoxicity of Pulverulentone A and its ability to combat Pseudomonas infection. Docking study was further performed to investigate Pulverulentone A druggability against main quorum sensing (QS) targets expressed by P. aeruginosa; (3) Results: Both C. citrinus extract and the isolated compound could inhibit biofilm formation, extracellular polymeric substances (EPS) and pigment production by the tested isolates. Unexpectedly, no significant inhibition was observed on proteases production. The in silico docking analysis revealed good interactions of Pulverulentone A with all QS targets examined (LasR, MyfR/PqsR, QscR). Pulverulentone A was safe up to 400 µg·mL−1 in Galleria caterpillars. Moreover, pre-treatment of P. aeruginosa with Pulverulentone A slightly enhanced the survival of the infected larvae. (4) Conclusions: The present study proves Pulverulentone A safety with significant in vitro and in silico antivirulence potential against P. aeruginosa.

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Treating Bacterial Infections with Bacteriophage-Based Enzybiotics: In Vitro, In Vivo, and Clinical Application

Antibiotics ◽

10.3390/antibiotics10121497 ◽

2021 ◽

Vol 10 (12) ◽

pp. 1497

Author(s):

Katarzyna M. Danis-Wlodarczyk ◽

Daniel J. Wozniak ◽

Stephen T. Abedon

Keyword(s):

Bacterial Infections ◽

Bacterial Resistance ◽

High Efficiency ◽

Cross Resistance ◽

Resistant Bacteria ◽

Drug Classes ◽

Peptidoglycan Hydrolases ◽

Bacterial Peptidoglycan

Over the past few decades, we have witnessed a surge around the world in the emergence of antibiotic-resistant bacteria. This global health threat arose mainly due to the overuse and misuse of antibiotics as well as a relative lack of new drug classes in development pipelines. Innovative antibacterial therapeutics and strategies are, therefore, in grave need. For the last twenty years, antimicrobial enzymes encoded by bacteriophages, viruses that can lyse and kill bacteria, have gained tremendous interest. There are two classes of these phage-derived enzymes, referred to also as enzybiotics: peptidoglycan hydrolases (lysins), which degrade the bacterial peptidoglycan layer, and polysaccharide depolymerases, which target extracellular or surface polysaccharides, i.e., bacterial capsules, slime layers, biofilm matrix, or lipopolysaccharides. Their features include distinctive modes of action, high efficiency, pathogen specificity, diversity in structure and activity, low possibility of bacterial resistance development, and no observed cross-resistance with currently used antibiotics. Additionally, and unlike antibiotics, enzybiotics can target metabolically inactive persister cells. These phage-derived enzymes have been tested in various animal models to combat both Gram-positive and Gram-negative bacteria, and in recent years peptidoglycan hydrolases have entered clinical trials. Here, we review the testing and clinical use of these enzymes.

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Antibacterial Effect of Silver Nanoparticles Synthesized Using Murraya koenigii (L.) against Multidrug-Resistant Pathogens

Bioinorganic Chemistry and Applications ◽

10.1155/2019/4649506 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 33

Author(s):

Faizan Abul Qais ◽

Anam Shafiq ◽

Haris M. Khan ◽

Fohad M. Husain ◽

Rais A. Khan ◽

...

Keyword(s):

Silver Nanoparticles ◽

Bacterial Infections ◽

Enteric Bacteria ◽

Multidrug Resistant ◽

Murraya Koenigii ◽

E Coli ◽

Vis Spectroscopy ◽

Zones Of Inhibition

Development of multidrug resistance among pathogens has become a global problem for chemotherapy of bacterial infections. Extended-spectrum β-lactamase- (ESβL-) producing enteric bacteria and methicillin-resistant Staphylococcus aureus (MRSA) are the two major groups of problematic MDR bacteria that have evolved rapidly in the recent past. In this study, the aqueous extract of Murraya koenigii leaves was used for synthesis of silver nanoparticles. The synthesized MK-AgNPs were characterized using UV-vis spectroscopy, FTIR, XRD, SEM, and TEM, and their antibacterial potential was evaluated on multiple ESβL-producing enteric bacteria and MRSA. The nanoparticles were predominantly found to be spheroidal with particle size distribution in the range of 5–20 nm. There was 60.86% silver content in MK-AgNPs. Evaluation of antibacterial activity by the disc-diffusion assay revealed that MK-AgNPs effectively inhibited the growth of test pathogens with varying sized zones of inhibition. The MICs of MK-AgNPs against both MRSA and methicillin-sensitive S. aureus (MSSA) strains were 32 μg/ml, while for ESβL-producing E. coli, it ranged from 32 to 64 μg/ml. The control strain of E. coli (ECS) was relatively more sensitive with an MIC of 16 μg/ml. The MBCs were in accordance with the respective MICs. Analysis of growth kinetics revealed that the growth of all tested S. aureus strains was inhibited (∼90%) in presence of 32 μg/ml of MK-AgNPs. The sensitive strain of E. coli (ECS) showed least resistance to MK-AgNPs with >81% inhibition at 16 μg/ml. The present investigation revealed an encouraging result on in vitro efficacy of green synthesized MK-AgNPs and needed further in vivo assessment for its therapeutic efficacy against MDR bacteria.

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Fenofibrate Solid Dispersion for Improving Oral Bioavailability: Preparation, and Characterization and in vivo Evaluation

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2020.13.5.7 ◽

2020 ◽

Vol 13 (5) ◽

pp. 5102-5109

Author(s):

Venu Madhav K ◽

Somnath De ◽

Chandra Shekar Bonagiri ◽

Sridhar Babu Gummadi

Keyword(s):

Oral Bioavailability ◽

Oral Delivery ◽

Solid Dispersions ◽

In Vitro Release ◽

Aqueous Solubility ◽

Water Soluble ◽

Scanning Calorimetry ◽

In Vivo Evaluation

Fenofibrate (FN) is used in the treatment of hypercholesterolemia. It shows poor dissolution and poor oral bioavailability after oral administration due to high liphophilicity and low aqueous solubility. Hence, solid dispersions (SDs) of FN (FN-SDs) were develop that might enhance the dissolution and subsequently oral bioavailability. FN-SDs were prepared by solvent casting method using different carriers (PEG 4000, PEG 6000, β cyclodextrin and HP β cyclodextrin) in different proportions (0.25%, 0.5%, 0.75% and 1% w/v). FN-SDs were evaluated solubility, assay and in vitro release studies for the optimization of SD formulation. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM) analysis was performed for crystalline and morphology analysis, respectively. Further, optimized FN-SD formulation evaluated for pharmacokinetic performance in Wistar rats, in vivo in comparison with FN suspension. From the results, FN-SD3 and FN-SD6 have showed 102.9 ±1.3% and 105.5±3.1% drug release, respectively in 2 h. DSC and PXRD studies revealed that conversion of crystalline to amorphous nature of FN from FT-SD formulation. SEM studies revealed the change in the orientation of FN when incorporated in SDs. The oral bioavailability FN-SD3 and FN-SD6 formulations exhibited 2.5-folds and 3.1-folds improvement when compared to FN suspension as control. Overall, SD of FN could be considered as an alternative dosage form for the enhancement of oral delivery of poorly water-soluble FN.

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Chemosensitizing Activity of Histone Deacetylases Inhibitory Cyclic Hydroxamic Acids for Combination Chemotherapy of Lymphatic Leukemia

Current Cancer Drug Targets ◽

10.2174/1568009617666170623104030 ◽

2018 ◽

Vol 18 (4) ◽

pp. 365-371 ◽

Cited By ~ 2

Author(s):

Denis V. Mishchenko ◽

Margarita E. Neganova ◽

Elena N. Klimanova ◽

Tatyana E. Sashenkova ◽

Sergey G. Klochkov ◽

...

Keyword(s):

Lipid Peroxidation ◽

Acute Toxicity ◽

Histone Deacetylases ◽

Hydroxamic Acids ◽

Water Soluble ◽

Male Rat ◽

Hybrid Male ◽

Cyclic Hydroxamic Acids

Background: Anti-tumor effect of hydroxamic acid derivatives is largely connected with its properties as efficient inhibitors of histone deacetylases, and other metalloenzymes involved in carcinogenesis. Objective: The work was aimed to (i) determine the anti-tumor and chemosensitizing activity of the novel racemic spirocyclic hydroxamic acids using experimental drug sensitive leukemia P388 of mice, and (ii) determine the structure-activity relationships as metal chelating and HDAC inhibitory agents. Method: Outbreed male rat of 200-220 g weights were used in biochemical experiments. In vivo experiments were performed using the BDF1 hybrid male mice of 22-24 g weight. Lipid peroxidation, Fe (II) -chelating activity, HDAC fluorescent activity, anti-tumor and anti-metastatic activity, acute toxicity techniques were used in this study. Results: Chemosensitizing properties of water soluble cyclic hydroxamic acids (CHA) are evaluated using in vitro activities and in vivo methods and found significant results. These compounds possess iron (II) chelating properties, and slightly inhibit lipid peroxidation. CHA prepared from triacetonamine (1a-e) are more effective Fe (II) ions cheaters, as compared to CHA prepared from 1- methylpiperidone (2a-e). The histone deacetylase (HDAC) inhibitory activity, lipophilicity and acute toxicity were influenced by the length amino acids (size) (Glycine < Alanine < Valine < Leucine < Phenylalanine). All compounds bearing spiro-N-methylpiperidine ring (2a-e) are non-toxic up to 1250 mg/kg dose, while compounds bearing spiro-tetramethylpiperidine ring (1a-e) exhibit moderate toxicity which increases with increasing lipophility, but not excite at 400 mg/kg. Conclusion: It was shown that the use of combination of non-toxic doses of cisplatin (cPt) or cyclophosphamide with CHA in most cases result in the appearance of a considerable anti-tumor effect of cytostatics. The highest chemosensitizing activity with respect to leukemia Р388 is demonstrated by the CHA derivatives of Valine 1c or 2c.

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Development, Characterization and In Vivo Pharmacokinetic Assessment of Rectal Suppositories Containing Combination Antiretroviral Drugs for HIV Prevention

Pharmaceutics ◽

10.3390/pharmaceutics13081110 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1110

Author(s):

Kunal Jhunjhunwala ◽

Charles W. Dobard ◽

Sunita Sharma ◽

Natalia Makarova ◽

Angela Holder ◽

...

Keyword(s):

Hiv Prevention ◽

Antiretroviral Drugs ◽

Water Soluble ◽

Fixed Dose ◽

Receptive Anal Intercourse ◽

On Demand ◽

Dose Combination ◽

Rectal Suppositories

Receptive anal intercourse (RAI) contributes significantly to HIV acquisition underscoring the need to develop HIV prevention options for populations engaging in RAI practices. We explored the feasibility of formulating rectal suppositories with potent antiviral drugs for on-demand use. A fixed-dose combination of tenofovir (TFV) and elvitegravir (EVG) (40 mg each) was co-formulated in six different suppository bases (three fat- and three water-soluble). Fat-soluble witepsol H15 and water-soluble polyethylene glycol (PEG) based suppositories demonstrated favorable in vitro release and were advanced to assess in vivo pharmacokinetics following rectal administration in macaques. In vivo drug release profiles were similar for both suppository bases. Median concentrations of TFV and EVG detected in rectal fluids at 2 h were 1- and 2-logs higher than the in vitro IC50, respectively; TFV-diphosphate levels in rectal tissues met or exceeded those associated with high efficacy against rectal simian HIV (SHIV) exposure in macaques. Leveraging on these findings, a PEG-based suppository with a lower dose combination of tenofovir alafenamide (TAF) and EVG (8 mg each) was developed and found to achieve similar rectal drug exposures in macaques. This study establishes the utility of rectal suppositories as a promising on-demand strategy for HIV PrEP and supports their clinical development.

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