Elucidating pharmacodynamic interaction of silver nanoparticle - topical deliverable antibiotics

Novel silver nanoparticle-antibiotic combinations as promising antibacterial and anti-biofilm candidates against multiple-antibiotic resistant ESKAPE microorganisms

HYPOTHESIS

The emergence of Multiple Antibiotic Resistance (MAR) in ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens is a global challenge to public health. The inherent antimicrobial nature of silver nanoparticles (AgNPs) makes them promising antimicrobial candidates against antibiotic-resistant pathogens. This study explores the combination of AgNPs with antibiotics (SACs) to create new antimicrobial agents effective against MAR ESKAPE microorganisms.

METHODS

AgNPs were synthesized using Streptococcus pneumoniae ATCC 49619 and characterized for structure and surface properties. The SACs were tested against ESKAPE microorganisms using growth kinetics and time-kill curve methods. The effect of SACs on bacterial biofilms and the disruption of cell membranes was determined. The in-vitro cytotoxicity effect of the AgNPs was also studied.

FINDINGS

The synthesized AgNPs (spherical, 7.37±4.55 nm diameter) were antimicrobial against MAR ESKAPE microorganisms. The SACs showed synergy with multiple conventional antibiotics, reducing their antibacterial concentrations up to 32-fold. Growth kinetics and time-kill studies confirmed the growth retardation effect and bactericidal activity of SACs. Mechanistic studies suggested that these biofilm-eradicating SACs probably resulted in the loss of bacterial cell membrane integrity, leading to leakage of the cytoplasmic content. The AgNPs were highly cytotoxic against skin melanoma cells but non-cytotoxic to normal Vero cells.

Investigation of Antibiofilm and Antibacterial Properties of Green Synthesized Silver Nanoparticles from Aqueous Extract of Rumex sp

The decrease in the effectiveness of conventional drugs as a result of the growth of resistance to antibiotics has increased the need for innovative tools to control the infections. At this point, metallic nanoparticles, in particular silver nanoparticles, have appeared as a promising method. In the current study, the extract of Rumex sp. (Labada, dock) leaves was used as a reducing agent for the formation of silver nanoparticles. Unlike similar studies, in this study the synthesis conditions were optimized by changing the extract ratio and silver nitrate concentration. Morphological investigations of synthesized silver nanoparticles showed that spherical homogeneous particles at size under 100 nm had been produced. SEM/EDS and FTIR analyses showed that plant components are involved in the synthesis of nanoparticles. It was also determined that higher extract ratio reduced nanoparticle size. The antimicrobial effects of the synthesized nanoparticles against Gram-positive and Gram-negative bacteria were tested, and it was determined that all nanoparticles exhibited activity against both groups. Rumex sp. silver nanoparticles (NPs) were revealed to exhibit antibiofilm activity against three different isolates with moderate and strong biofilm-forming ability. The NPs reduced the biofilm-forming capacity of Acinetobacter baumannii and Klebsiella pneumonaie by 2.66-fold and 3.25-fold, whereas they decreased the Escherichia coli biofilm-forming capacity by 1.25-fold. The investigation of microbial biofilm could play an important role in developing new strategies for treatment options. Our results suggest that Rumex sp. silver NPs may have a high potential for use in the treatment of pathogenic strains.

Nanoparticles and Their Antibacterial Application in Endodontics

Root canal treatment represents a significant challenge as current cleaning and disinfection methodologies fail to remove persistent bacterial biofilms within the intricate anatomical structures. Recently, the field of nanotechnology has emerged as a promising frontier with numerous biomedical applications. Among the most notable contributions of nanotechnology are nanoparticles, which possess antimicrobial, antifungal, and antiviral properties. Nanoparticles cause the destructuring of bacterial walls, increasing the permeability of the cell membrane, stimulating the generation of reactive oxygen species, and interrupting the replication of deoxyribonucleic acid through the controlled release of ions. Thus, they could revolutionize endodontics, obtaining superior results and guaranteeing a promising short- and long-term prognosis. Therefore, chitosan, silver, graphene, poly(lactic) co-glycolic acid, bioactive glass, mesoporous calcium silicate, hydroxyapatite, zirconia, glucose oxidase magnetic, copper, and zinc oxide nanoparticles in endodontic therapy have been investigated in the present review. The diversified antimicrobial mechanisms of action, the numerous applications, and the high degree of clinical safety could encourage the scientific community to adopt nanoparticles as potential drugs for the treatment of endodontic diseases, overcoming the limitations related to antibiotic resistance and eradication of the biofilm.

Nanosilver: An Old Antibacterial Agent with Great Promise in the Fight against Antibiotic Resistance

Antibiotic resistance in bacteria is a major problem worldwide that costs 55 billion USD annually for extended hospitalization, resource utilization, and additional treatment expenditures in the United States. This review examines the roles and forms of silver (e.g., bulk Ag, silver salts (AgNO3), and colloidal Ag) from antiquity to the present, and its eventual incorporation as silver nanoparticles (AgNPs) in numerous antibacterial consumer products and biomedical applications. The AgNP fabrication methods, physicochemical properties, and antibacterial mechanisms in Gram-positive and Gram-negative bacterial models are covered. The emphasis is on the problematic ESKAPE pathogens and the antibiotic-resistant pathogens of the greatest human health concern according to the World Health Organization. This review delineates the differences between each bacterial model, the role of the physicochemical properties of AgNPs in the interaction with pathogens, and the subsequent damage of AgNPs and Ag+ released by AgNPs on structural cellular components. In closing, the processes of antibiotic resistance attainment and how novel AgNP-antibiotic conjugates may synergistically reduce the growth of antibiotic-resistant pathogens are presented in light of promising examples, where antibiotic efficacy alone is decreased.

Antibacterial Activity of Silver Nanoparticles Synthesized by Aspergillus flavus and its Synergistic Effect with Antibiotics

Microbial antibiotic resistance is rapidly increasing as a result of overuse or misuse of antibiotics, as well as a lack of new, effective antibiotics. Alternative antimicrobial treatments, such as nanoparticles, and their potential for stronger synergetic effect when paired with other active chemicals, could be a viable option. This study is prepared to estimate the antibacterial activity of silver nanoparticles (AgNPs) that have been synthesized using the biomass-free filtrate of Aspergillus flavus. The formation of AgNPs was reported by color changed to a dark brownish-black after 72 hours of incubation. The AgNPs surface plasmon resonance peak was indicated in the UV–Vis spectrum at 427 nm. The synthesis of AgNPs with a nanoparticle size of 10 to 35 nm was validated using transmission electron microscopy. The increase in folding area was calculated to detect the synergistic potential of the combined AgNPs with a broad range of conventional antibiotics. AgNPs have broad-spectrum activity against all strains tested. The most sensitive strain was Escherichia coli (11 mm), whereas the most resistant strain was Pseudomonas aeruginosa, as indicated by the lowest inhibition zone (7 mm). The lowest Minimum Inhibitory Concentration indicated was against K. pneumonia and Enterobacter cloacae (0.025 mg/mL, each), followed by Staphylococcus epidermidis (0.05 mg/mL), E. coli and Shigella sp. (0.075 mg/mL, each), and then S. aureus (0.1 mg/mL). Notable synergy was reported between AgNPs and either ampicillin, erythromycin, ceftriaxone, vancomycin, azlocillin, or amoxicillin against S. aureus in the range between 29.3-fold to 8-fold. In addition, synergy was seen between AgNPs and either vancomycin, clindamycin, or erythromycin against P. aeruginosa (31.1-8.0-fold). Also, a maximum increase in IFA when erythromycin and vancomycin were synergized with AgNPs against E. cloacae was reported (IFA of 10.0 and 9.0, respectively). Similarly, AgNPs with either aztreonam or azlocillin against E. coli and amoxicillin, ciprofloxacin, or ceftriaxone against Shigella sp. caused an increase in the fold area of inhibition of between 5.3-3.7-fold. This result may have an advantage in encouraging the use of combined AgNPS with conventional antibiotics in treating infectious diseases caused by antibiotic-resistant bacteria.

Meropenem-Loaded Nanostructured Lipid Carriers For Skin and Soft Tissue Infection Caused by Staphylococcus aureus: Formulation, Design, and Evaluation

AIM

Meropenem hydrochloride (MpM)-loaded nanostructured lipid carriers were designed for the effective management of skin infection caused by Staphylococcus aureus via topical route. The solvent evaporation tactic was preferred to develop nanostructured lipid carriers (NLCs). Stearic acid was used as a solid fatty acid; oleic acid was used as liquid fatty acid and Tween 80 as a surfactant. The Staphylococcus aureus burden was analyzed by pharmacodynamic studies. The skin retention was analyzed by fluorescence microscopy. Spherical shape of NLCs was confirmed by TEM. The optimum particle size of the MpM-NLCs was ~ 126.5 ± 0.9 nm with 79.1 ± 2.3% entrapment (EE) and 0.967 mV zeta potential. The in vitro release studies revealed 81.5 ± 3.1% release of drug in 48 h, while the pure drug was almost completely released (98.4 ± 1.4%) within 24 h confirming the potential of NLCs for sustained topical drug delivery. Skin permeation study also revealed better permeation of drug from NLCs than of plain drug. The prepared MpM-NLCs when stored at 4 ± 2°C for 90 days were found to be more stable when the formulation was stored at 28 ± 2°C. The S. aureus burden was analyzed by evaluating the zone of inhibition (ZOI). The ZOI of MpM alone and MpM-NLC gel was measured and compared with that of the control group. The MpM was found significantly effective when its gel was prepared with NLCs because of its enhanced adhesion property occlusion and ability to sustain release. In overall, the study's outcomes validated the relevance of NLC's composition as a vehicle for topical MpM administration in skin diseases caused by Staphylococcus aureus.

Nanoparticles in Endodontics Disinfection: State of the Art

Endodontic-related diseases constitute the fourth most expensive pathologies in industrialized countries. Specifically, endodontics is the part of dentistry focused on treating disorders of the dental pulp and its consequences. In order to treat these problems, especially endodontic infections, dental barriers and complex root canal anatomy should be overcome. This constitutes an unmet medical need since the rate of successful disinfection with the currently marketed drugs is around 85%. Therefore, nanoparticles constitute a suitable alternative in order to deliver active compounds effectively to the target site, increasing their therapeutic efficacy. Therefore, in the present review, an overview of dental anatomy and the barriers that should be overcome for effective disinfection will be summarized. In addition, the versatility of nanoparticles for drug delivery and their specific uses in dentistry are comprehensively discussed. Finally, the latest findings, potential applications and state of the art nanoparticles with special emphasis on biodegradable nanoparticles used for endodontic disinfection are also reviewed.

Combining antibiotics with silver nanoparticles: A potential treatment strategy against antimicrobial resistance

Growing resistance to currently approved antibiotics is posing serious concern worldwide. The multidrug-resistant organisms are a major cause of mortality and morbidity around the globe. The limited options to treat infections caused by resistant organism requires alternative strategies to increase the effectiveness of antibiotic for better clinical outcomes. Recent advances in nanotechnology have enabled the drugs to be used in nanoscale to increase the effectiveness of antibiotics. The use of nanoparticles to treat infectious diseases has a long history in the pharmaceutical market, and the versatility of these particles to incorporate various materials as carriers make it an attractive option to combat the current crisis of emerging antibacterial resistance. Silver, a metal with many medical applications, has inherent antimicrobial properties. Therefore, silver NPs are appearing as one of the best options to be used in combination with antibiotics to increase effectiveness against resistant bacteria. Here, we discuss the applications and mechanisms of silver NPs to treat microbial resistance in light of recent research.

Silver nanoparticles as a bioadjuvant of antibiotics against biofilm-mediated infections with methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in chronic rhinosinusitis patients

Infectious diseases caused by antibiotic-resistant bacteria in planktonic and biofilm form are difficult to treat with conventional antibiotics. Silver nanoparticles (Ag NPs) can be used as alternatives to antibiotics and can alter the susceptibility of bacteria to antibiotics. Here, the antibacterial properties of 16 different antibiotics and Ag NPs, alone and in combination, were tested against clinical isolates of Pseudomonas aeruginosa (n=3), Staphylococcus aureus (n=3) and methicillin-resistant Staphylococcus aureus (MRSA) (n=2) isolated from chronic rhinosinusitis (CRS) patients. The microdilution method and resazurin assay were used to determine the minimum inhibitory concentration and minimum biofilm eradication concentration for planktonic and biofilm forms, respectively. Results showed that Ag NPs and gentamicin combinations had synergistic antibacterial activity against P. aeruginosa planktonic and biofilm forms and MRSA biofilms. Furthermore, additive effects against biofilms were seen for combinations of Ag NPs with tobramycin or ciprofloxacin against P. aeruginosa; with mupirocin against MRSA; and with augmentin, doxycycline, azithromycin and clindamycin against S. aureus. Moreover, additive effects against planktonic forms were observed for combinations of Ag NPs with tobramycin, ciprofloxacin, imipenem, ceftazidime and aztreonam against P. aeruginosa; with gentamicin or linezolid against MRSA; and with doxycycline or clindamycin against S. aureus. In conclusion, Ag NP-antibiotic combinations can result in enhanced antimicrobial action against P. aeruginosa, MRSA and S. aureus clinical isolates in planktonic and biofilm forms and can be used in the context of CRS with confirmed infection.

Recent developments in biomolecule-based nanoencapsulation systems for antimicrobial delivery and biofilm disruption

Biomolecules are very attractive nanomaterial components, generally, due to their biocompatibility, biodegradability, abundance, renewability, and sustainability, as compared to other resources for nanoparticle-based delivery systems. Biomolecule-based nanoencapsulation and nanodelivery systems can be designed and engineered for antimicrobial cargos in order to surmount classical and current challenges, including the emergence of multi-drug resistant strains of microorganisms, the low effectiveness and limitations in the applicability of the present antimicrobials, and biofilm formation. This feature article highlights the recent applications and capabilities of biomacromolecule-based nanomaterials for the delivery and activity enhancement of antimicrobials, and disruption of biofilms. Unique properties of some nanomaterials, arising from specific biomacromolecules, were also emphasized. We expect that this review will be helpful to researchers in engineering new types of antimicrobial nanocarriers, hybrid particles and colloidal systems with tailored properties.

Utilizing of (Zinc Oxide Nano-Spray) for Disinfection against “SARS-CoV-2” and Testing Its Biological Effectiveness on Some Biochemical Parameters during (COVID-19 Pandemic)—”ZnO Nanoparticles Have Antiviral Activity against (SARS-CoV-2)”

A newly synthesized zinc (II) oxide nanoparticle (ZnO-NPs) has been used as a disinfectant Nano-spray for the emerging corona virus (SARS-CoV-2). The synthesized obtained nanomaterial of (ZnO) was fully chemically characterized by using different spectroscopic analysis (FT-IR, UV and XRD) and surface analysis techniques. ZnO-Nps surface morphology and chemical purity has been investigated by transmission electron microscope (TEM), high resolution transmission electron microscope (HR-TEM), scanning electron microscopy (SEM) as well as energy dispersive X-ray analysis (EDX), Additionally Zeta potential and Zeta size distribution were measured and evaluated to confirm its nano-range scale. The synthesized Zno-NPs have been tested using 10% DMSO and ddH2O for estimation of antiviral activity against (SARS-CoV-2) by using cytotoxicity assay (CC50) and inhibitory concentration (IC50). The results revealed that (Zno-NPs) has high anti-SARS-CoV-2 activity at cytotoxic concentrations in vitro with non-significant selectivity index (CC50/IC50 ≤ 1). The current study results demonstrated the (ZnO-NPs) has potent antiviral activity at low concentration (IC50 = 526 ng/mL) but with some cytotoxic effect to the cell host by (CC50 = 292.2 ng/mL). We recommend using of (ZnO-NPs) as potent disinfectant against (SARS-Cov-2), but there are slight side effects on the cellular host, so we recommend more prospective studies on complexation of other compounds with (ZnO-NPs) in different concentrations to reduce its cellular toxicity and elevate its antiviral activity against SARS-CoV-2 activities.

Recent advances in Staphylococcus aureus infection: focus on vaccine development

Staphylococcus aureus normally colonizes the nasal cavity and pharynx. After breaching the normal habitat, the organism is able to cause a number of infections at any site of the body. The development of antibiotic resistance has created a global challenge for treating infections. Therefore, protection by vaccines may provide valuable measures. Currently, several vaccine candidates have been prepared which are either in preclinical phase or in early clinical phase, whereas several candidates have failed to show a protective efficacy in human subjects. Approaches have also been made in the development of monoclonal or polyclonal antibodies for passive immunization to protect from S. aureus infections. Therefore, in this review we have summarized the findings of recently published scientific literature to make a concise report.

Evaluation of antibacterial efficacy of sulfur nanoparticles alone and in combination with antibiotics against multidrug-resistant uropathogenic bacteria

Urinary tract infections (UTIs) have been frequently reported from different parts of the world. The current knowledge on distribution of causative agents of urinary infections and antibiotics susceptibility pattern is essentially required. In the present study, total 351 uropathogenic bacteria were isolated; among them most prevalent were Escherichia coli (75%), followed by Pseudomonas aeruginosa (8%), Proteus mirabilis (6%), Klebsiella pneumoniae (4%), Staphylococcus aureus (4%) and Enterococcus faecalis (3%). Most isolates of uropathogenic bacteria showed resistance to amoxicillin and trimethoprim, followed by chloramphenicol and kanamycin. Biosynthesis of sulfur nanoparticles (SNPs) was performed by co-precipitation method using sodium thiosulfate in presence of Catharanthus roseus leaf extract. The characterization data showed that SNPs were polydispersed, spherical in shape with size range of 20-86 nm and having negative zeta potential of -9.24 mV. The potential antibacterial activity was observed for SNPs alone and in combination with antibiotics particularly amoxicillin and trimethoprim against majority of the uropathogens. The synergistic effect yielded increase in fold area with high activity index against tested uropathogens. Based on overall results, it can be recommended to use SNPs for the management of UTI alone and also in combination with antibiotics.

Augmented antibacterial activity of ampicillin with silver nanoparticles against methicillin-resistant Staphylococcus aureus (MRSA)

At present, including failed attempts, it takes about 15 years and costs totaling up to $2.6 billion to take a promising new compound from laboratory to the market. Increasing drug resistance among microbial pathogens has led to a growing interest in exploring novel methods to enhance the efficacy of existing drugs. Combination therapies involving two or more known antimicrobial methods, particularly those involving nanoparticles for combating the clinical problems associated with antibiotic resistance, have been garnering interest. In the current study, we determined whether a combination therapy involving silver nanoparticles, which are known for their antimicrobial activity, and the widely used antibiotic ampicillin can be effective against methicillin-resistant Staphylococcus aureus (MRSA). In the presence of sub-lethal dose of silver nanoparticles, ampicillin was found to be effective against MRSA. Indeed, the results show that silver nanoparticles and ampicillin act synergistically, with the effect being more pronounced when a lower concentration of ampicillin is present. When present at a higher concentration, ampicillin coats the silver nanoparticle, preventing the direct interaction of nanoparticles and bacteria. This study discusses the possible applications of combination antimicrobial therapies involving silver nanoparticles for therapeutic treatments.

Silver nanoparticles as antimicrobial therapeutics: current perspectives and future challenges

Utility of silver metal in antimicrobial therapy is an accepted practice since ages that faded with time because of the identification of a few silver resistant strains in the contemporary era. A successive development of antibiotics soon followed. However, due to an indiscriminate and unregulated use coupled with poor legal control measures and a dearth of expertise in handling the critical episodes, the antibiotics era has already seen a steep decline in the past decades due to the evolution of multi-drug resistant 'superbugs' which pose a sizeable challenge to manage with. Due to limited options in the pipeline and no clear strategy in the forefront, the aspirations for novel, MDR focused drug discovery to target the 'superbugs' arose which once again led to the rise of AgNPs in antimicrobial research. In this review, we have focused on the green routes for the synthesis of AgNPs, the mode of microbial inhibition by AgNPs, synergistic effect of AgNPs with antibiotics and future challenges for the development of nano-silver-based therapeutics.

Zirconyl Clindamycinphosphate Antibiotic Nanocarriers for Targeting Intracellular Persisting Staphylococcus aureus

[ZrO]²⁺[CLP]^2- (CLP: clindamycinphosphate) inorganic-organic hybrid nanoparticles (IOH-NPs) represent a novel strategy to treat persisting, recurrent infections with multiresistant Staphylococcus aureus. [ZrO]²⁺[CLP]^2- is prepared in water and contains the approved antibiotic with unprecedented high load (82 wt % CLP per nanoparticle). The IOH-NPs result in 70-150-times higher antibiotic concentrations at difficult-to-reach infection sites, offering new options for improved drug delivery for chronic and difficult-to-treat infections.

Enhancing the antimicrobial and antibiofilm effectiveness of silver nanoparticles prepared by green synthesis

Water soluble catechin oligomers produce small (8.5 nm) silver nanoparticles with high antimicrobial and antibiofilm efficacy.

Temperature/pH-Sensitive Nanoantibiotics and Their Sequential Assembly for Optimal Collaborations between Antibacterial and Immunoregulation

Treatment of bacterial infections due to the fast emergence of drug-resistant bacteria is a significant challenge faced in modern medicine. Here the authors report a drug-induced self-assembly nanoantibiotic for treating bacterial infection, with temperature/pH-sensitivity, synergistic antibacterial effect of silver and antibiotics, and immunoregulatory effect. In this nanoantibiotic, smart polymer p(N-isopropylacrylamide-b-acrylic acid) triblock polymer (PNA) utilized to encapsulate the drugs provides convenience in preparing this structure simply through drug-induced self-assembly and controllable release profile by changing the sequence of addition of different drugs. The polymer also allows the nanoantibiotic to be responsive to multiple external stimuli such as pH, temperature, and ionic strength. The silver and antibiotics codelivered in this nanoantibiotic can exert a synergistic antibacterial effect due to the different antibacterial mechanisms. More importantly, macrophages can be activated into an M2 phenotype to promote tissue repair by this nanoantibiotic for the negative surface charge and the antibiotics contained. The self-assembly nanoantibiotic exhibited great promise to be applied in the treatment of bacterial infection and provide favorable utility for inflammation treatment, tissue engineering, and targeted therapy.

Metal-Based Nanoparticles for the Treatment of Infectious Diseases

Infectious diseases can be transmitted and they cause a significant burden on public health globally. They are the greatest world killers and it is estimated that they are responsible for the demise of over 17 million people annually. The impact of these diseases is greater in the developing countries. People with compromised immune systems and children are the most affected. Infectious diseases may be caused by bacteria, viruses, and protozoa. The treatment of infectious diseases is hampered by simultaneous resistance to multiple drugs, indicating that there is a serious and pressing need to develop new therapeutics that can overcome drug resistance. This review will focus on the recent reports of metal-based nanoparticles that are potential therapeutics for the treatment of infectious diseases and their biological efficacy (in vitro and in vivo).