scholarly journals Antimicrobial Gold Nanoclusters: Recent Developments and Future Perspectives

2019 ◽  
Vol 20 (12) ◽  
pp. 2924 ◽  
Author(s):  
Sibidou Yougbare ◽  
Ting-Kuang Chang ◽  
Shih-Hua Tan ◽  
Jui-Chi Kuo ◽  
Po-Hsuan Hsu ◽  
...  

Bacterial infections have caused serious threats to public health due to the antimicrobial resistance in bacteria. Recently, gold nanoclusters (AuNCs) have been extensively investigated for biomedical applications because of their superior structural and optical properties. Great efforts have demonstrated that AuNCs conjugated with various surface ligands are promising antimicrobial agents owing to their high biocompatibility, polyvalent effect, easy modification and photothermal stability. In this review, we have highlighted the recent achievements for the utilizations of AuNCs as the antimicrobial agents. We have classified the antimicrobial AuNCs by their surface ligands including small molecules (<900 Daltons) and macromolecules (>900 Daltons). Moreover, the antimicrobial activities and mechanisms of AuNCs have been introduced into two main categories of small molecules and macromolecules, respectively. In accordance with the advancements of antimicrobial AuNCs, we further provided conclusions of current challenges and recommendations of future perspectives of antimicrobial AuNCs for fundamental researches and clinical applications.

2019 ◽  
Vol 20 (6) ◽  
pp. 457-472 ◽  
Author(s):  
Naga Veera Srikanth Vallabani ◽  
Sanjay Singh ◽  
Ajay Singh Karakoti

Background: Biomedical applications of Magnetic Nanoparticles (MNPs) are creating a major impact on disease diagnosis and nanomedicine or a combined platform called theranostics. A significant progress has been made to engineer novel and hybrid MNPs for their multifunctional modalities such as imaging, biosensors, chemotherapeutic or photothermal and antimicrobial agents. MNPs are successfully applied in biomedical applications due to their unique and tunable properties such as superparamagnetism, stability, and biocompatibility. Approval of ferumoxytol (feraheme) for MRI and the fact that several Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are currently undergoing clinical trials have paved a path for future MNPs formulations. Intensive research is being carried out in designing and developing novel nanohybrids for multiple applications in nanomedicine. Objective: The objective of the present review is to summarize recent developments of MNPs in imaging modalities like MRI, CT, PET and PA, biosensors and nanomedicine including their role in targeting and drug delivery. Relevant theory and examples of the use of MNPs in these applications have been cited and discussed to create a thorough understanding of the developments in this field. Conclusion: MNPs have found widespread use as contrast agents in imaging modalities, as tools for bio-sensing, and as therapeutic and theranostics agents. Multiple formulations of MNPs are in clinical testing and may be accepted in clinical settings in near future.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2108
Author(s):  
Yin Wang ◽  
Hui Sun

Bacterial infections have threatened the lives of human beings for thousands of years either as major diseases or complications. The elimination of bacterial infections has always occupied a pivotal position in our history. For a long period of time, people were devoted to finding natural antimicrobial agents such as antimicrobial peptides (AMPs), antibiotics and silver ions or synthetic active antimicrobial substances including antimicrobial peptoids, metal oxides and polymers to combat bacterial infections. However, with the emergence of multidrug resistance (MDR), bacterial infection has become one of the most urgent problems worldwide. The efficient delivery of antimicrobial agents to the site of infection precisely is a promising strategy for reducing bacterial resistance. Polymeric nanomaterials have been widely studied as carriers for constructing antimicrobial agent delivery systems and have shown advantages including high biocompatibility, sustained release, targeting and improved bioavailability. In this review, we will highlight recent advances in highly efficient delivery of antimicrobial agents by polymeric nanomaterials such as micelles, vesicles, dendrimers, nanogels, nanofibers and so forth. The biomedical applications of polymeric nanomaterial-based delivery systems in combating MDR bacteria, anti-biofilms, wound healing, tissue engineering and anticancer are demonstrated. Moreover, conclusions and future perspectives are also proposed.


2020 ◽  
Vol 13 (05) ◽  
pp. 2030012 ◽  
Author(s):  
Zhimei Wei ◽  
Liqun Wang ◽  
Shouyu Zhang ◽  
Tonghai Chen ◽  
Jie Yang ◽  
...  

Bacterial infections are a major cause of chronic infections. Thus, antibacterial material is an urgent need in clinics. Antibacterial nanofibers, with expansive surface area, enable efficient incorporation of antibacterial agents. Meanwhile, structure similar to the extracellular matrix can accelerate cell growth. Electrospinning, the most widely used technique to fabricate nanofiber, is often used in many biomedical applications including drug delivery, regenerative medicine, wound healing and so on. Thus, this review provides an overview of all recently published studies on the development of electrospun antibacterial nanofibers in wound dressings and tissue medicinal fields. This reviewer begins with a brief introduction of electrospinning process and then discusses electrospun fibers by incorporating various types of antimicrobial agents used as in wound dressings and tissue. Finally, we finish with conclusions and further perspectives on electrospun antibacterial nanofibers as 2D biomedicine materials.


2020 ◽  
Vol 16 (2) ◽  
pp. 207-212
Author(s):  
Wissam Zam ◽  
Ali Ali ◽  
Walaa Ibrahim

Background and Objective: With the significant increase in the prevalence of infectious diseases and the development of drug resistance by human pathogenic bacteria, there is a continuous need to discover new antimicrobial compounds from plants. Methods: Four extracts of wild Myrtus communis L. berries (myrtle berries) were prepared with the addition of Cinnamomum verum and Eugenia caryophyllata. The extracts were screened in vitro for their antimicrobial activities using agar-well diffusion method against Escherichia coli, Staphylococcus aureus, Enterobacter cloacae, Listeria monocytogenes, Pseudomonas aeruginosa and Proteus mirabilis cultures. Results: The inhibition zones ranged from 12 to 22 mm. The MICs values of extracts lies between the ranges of 30 to 100 mg/ml. Of the extracts studied, the most active ones were those obtained from the myrtle berries:cloves, myrtle berries:cinnamon:cloves with the highest inhibition zones 22 mm and 17mm against S. aureus and L. monocytogenes at 50 mg/ml and 80 mg/ml, respectively. None of the extracts was active against E. coli and P. mirabilis. Conclusion: The present investigations have exposed that the myrtle berries:cloves, myrtle berries: cinnamon:cloves extracts could be used in traditional medicine as natural antimicrobial agents in treatment the bacterial infections.


Author(s):  
Snežana Radisavljević ◽  
Biljana Petrović

Gold nanoparticles (AuNPs) are widely used in biomedical applications, especially diagnostic and drug delivery. The antibacterial activity of nanoparticles depends on the dimensions of the particles. AuNPs may associate with the surface of the cell membrane and cause disorder such as respiration and permeability. The method of binding of particles for bacteria depends on their surface available for interaction. Smaller particles which have the larger surface area available for interaction will show better bactericidal effect than the larger particles. Useful antibacterial agents should also be toxic to various pathogenic bacteria with the ability to coat different surfaces like biomaterials, devices, textiles, food packaging, and so on. The biological and physiochemical properties of synthesized AuNPs have impact on the use of gold nanoparticles like antimicrobial agents, especially for water purification, as well as other biomedical applications.


Author(s):  
Derya Doğanay ◽  
Sevval M. Özcan ◽  
Ahmet M. Şentürk ◽  
Süreyya Ölgen

Background: Besides the viral infections, bacterial infections can cause serious and life-threatening complications and drug resistance is an important problem to fight bacterial infections. Therefore, it is important to discover novel antimicrobial agents to fight such infections. Objective: Several indole containing antimicrobial drug development studies have been reported in literature that provided strong evidences for good antimicrobial activities against a variety of microorganisms. Taken into consideration from these findings, antimicrobial properties of previously synthesized 16 indole amide derivatives were evaluated by in vitro tests against 14 different microorganisms, and also molecular docking and in silico prediction studies were used to identify structure-activity relationship of compounds. Methods: Antimicrobial activity of compounds was determined by disc diffusion and tube dilution methods. Molecular docking of compounds was studied to determine the relationship between the structure of compounds with DNA gyrase interactions of microorganisms by using the version of Autodock vina 4.2.6. Mol inspiration and Swiss ADME prediction online software programs were also used to identify drug-like properties of compounds. Results: The results showed that some compounds exhibited quite pronounced antibacterial and antifungal activities compared to reference drugs. These results were also supported by molecular docking studies and in silico ADME calculations presented that all tested compounds obey the Lipinski’s Rule of Five and are metabolized by CYP450 enzymes. Conclusion: It can be concluded that these results can be taken as reference in the development of new indole-based antimicrobial agents.


2021 ◽  
Author(s):  
Ahmed El-Sherif ◽  
Abeer A. El-Sisi ◽  
Mohamed Ali ◽  
Sohair F. Ramdan ◽  
Osama AlTaweel ◽  
...  

Abstract Series of thiosemicarbazone compounds ((E)-2-((E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazine-1-carbothioamide (TSC1), (E)-N-ethyl-2-((E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazine-1-carbothioamide (TSC2) and (E)-N-phenyl-2-((E)-1-(2-(p-tolyl)hydrazono)propan-2-ylidene)hydrazine-1-carbothioamide)(TSC3) were synthesized and fully characterized by assistance of diverse physicochemical and spectroscopic tools like X-ray single-crystal, IR, mass, 1HNMR, Uv-Vis,…etc. potentiometric measurements, molecular modeling, as well as biological and antitumor activities screening. We have calculated and discussed the thermodynamics and protonation constants of TSC1 compound as a representative from the novel synthesized thiosemicarbazones. The solution speciation of different species was studied in accordance with pH. Molecular parameters of the optimized structures were calculated and discussed. The X-ray single crystal of TSC2 and TSC3 compounds have been established where TSC2 crystallizes in P21/c, a = 11.2343 (6) Å, b = 11.2575 (7) Å, c =11.8995 (8) Å, α = 90.00°, β = 94.476(7) °, γ = 90.0°, V = 1500.34 (16) Å3, Z = 4, however, TSC3 crystallizes in the space group P21/c, a = 27.958 (12) Å, b= 12.072 (5) Å, c = 9.833 (4) Å, α = 90.0°, β = 93.117(11) °, γ = 90.0°, V = 3486.75 Å3, Z = 7. Considering the antimicrobial activities and correlating structure-activity relationship for the synthesized compounds, TSC1 molecule behaves as a promising candidate as an antifungal agent versus Candida albicans. Consequently, that would be very helpful in the field of medicinal chemistry especially as antimicrobial agents. The results are of vital significance to the chemistry of antimicrobial agents.


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2870
Author(s):  
Md Abdul Wahab ◽  
Li Luming ◽  
Md Abdul Matin ◽  
Mohammad Rezaul Karim ◽  
Mohammad Omer Aijaz ◽  
...  

Silver has become a potent agent that can be effectively applied in nanostructured nanomaterials with various shapes and sizes against antibacterial applications. Silver nanoparticle (Ag NP) based-antimicrobial agents play a major role in different applications, including biomedical applications, as surface treatment and coatings, in chemical and food industries, and for agricultural productivity. Due to advancements in nanoscience and nanotechnology, different methods have been used to prepare Ag NPs with sizes and shapes reducing toxicity for antibacterial applications. Studies have shown that Ag NPs are largely dependent on basic structural parameters, such as size, shape, and chemical composition, which play a significant role in preparing the appropriate formulation for the desired applications. Therefore, this review focuses on the important parameters that affect the surface interaction/state of Ag NPs and their influence on antimicrobial activities, which are essential for designing future applications. The mode of action of Ag NPs as antibacterial agents will also be discussed.


Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.


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