Indarchand Gupta

Silver Nanoparticles: Therapeutical Uses, Toxicity, and Safety Issues

The promises of nanotechnology have been realized to deliver the greatest scientific and technological advances in several areas. The biocidal activity of Metal nanoparticles in general and silver nanoparticles (AgNPs) depends on several morphological and physicochemical characteristics of the particles. Many of the interactions of the AgNPs with the human body are still poorly understood; consequently, the most desirable characteristics for the AgNPs are not yet well established. Therefore, the development of nanoparticles with well-controlled morphological and physicochemical features for application in human body is still an active area of interdisciplinary research. Effects of the development of technology of nanostructured compounds seem to be so large and comprehensive that probably it will impact on all fields of science and technology. However, mechanisms of safety control in application, utilization, responsiveness, and disposal accumulation still need to be further studied in-depth to ensure that the advances provided by nanotechnology are real and liable to provide solid and consistent progress. This review aims to discuss AgNPs applied in biomedicine and as promising field for insertion and development of new compounds related to medical and pharmacy technology. The review also addresses drug delivery, toxicity issues, and the safety rules concerning biomedical applications of silver nanoparticles.

Biogenic synthesis of metal nanoparticles from actinomycetes: biomedical applications and cytotoxicity

Biogenic synthesis of metal nanoparticles has been well proved by using bacteria, fungi, algae, actinomycetes, plants, etc. Among the different microorganisms used for the synthesis of metal nanoparticles, actinomycetes are less known. Although, there are reports, which have shown that actinomycetes are efficient candidates for the production of metal nanoparticles both intracellularly and extracellularly. The nanoparticles synthesized by the members of actinomycetes present good polydispersity and stability and possess significant biocidal activities against various pathogens. The present review focuses on biological synthesis of metal nanoparticles and their application in medicine. In addition, the toxicity of these biogenic metal nanoparticles to human beings and environment has also been discussed.

Bioactivity of noble metal nanoparticles decorated with biopolymers and their application in drug delivery

The unique properties of nanomaterials can be applied to solve different problems including new ways of drug delivery. Noble metal nanoparticles are most promising because they have been used for medicinal purposes since ancient time. It is evident from the past studies that the metallic nanoparticles are much more effective against various microorganisms when compared to their conventional counterparts. However, decoration of such nanoparticles with biomaterials add more advantages to their antimicrobial activity. Decoration of metal nanoparticles with biopolymers is a quite new area of research. Studies performed hitherto shown that nanoparticles of noble metals like silver, gold and platinum demonstrated better antibacterial, antifungal and antiviral activities when conjugated with biopolymers. The development of such technology has potential to develop materials that are more effective in the field of health science. Considering the importance and uniqueness of this concept, the present review aims to discuss the use of biopolymer-decorated metal nanoparticles for combating various diseases caused by microbial pathogens. Moreover, the nanotoxicity aspect has also been discussed.

Metal nanoparticles: The protective nanoshield against virus infection.

Abstract Re-emergence of resistance in different pathogens including viruses are the major cause of human disease and death, which is posing a serious challenge to the medical, pharmaceutical and biotechnological sectors. Though many efforts have been made to develop drug and vaccines against re-emerging viruses, researchers are continuously engaged in the development of novel, cheap and broad-spectrum antiviral agents, not only to fight against viruses but also to act as a protective shield against pathogens attack. Current advancement in nanotechnology provides a novel platform for the development of potential and effective agents by modifying the materials at nanolevel with remarkable physicochemical properties, high surface area to volume ratio and increased reactivity. Among metal nanoparticles, silver nanoparticles have strong antibacterial, antifungal and antiviral potential to boost the host immunity against pathogen attack. Nevertheless, the interaction of silver nanoparticles with viruses is a largely unexplored field. The present review discusses antiviral activity of the metal nanoparticles, especially the mechanism of action of silver nanoparticles, against different viruses such HSV, HIV, HBV, MPV, RSV, etc. It is also focused on how silver nanoparticles can be used in therapeutics by considering their cytotoxic level, to avoid human and environmental risks.

Recent advances in use of silver nanoparticles as antimalarial agents

Malaria is one of the most common infectious diseases, which has become a great public health problem all over the world. Ineffectiveness of available antimalarial treatment is the main reason behind its menace. The failure of current treatment strategies is due to emergence of drug resistance in Plasmodium falciparum and drug toxicity in human beings. Therefore, the development of novel and effective antimalarial drugs is the need of the hour. Considering the huge biomedical applications of nanotechnology, it can be potentially used for the malarial treatment. Silver nanoparticles (AgNPs) have demonstrated significant activity against malarial parasite (P. falciparum) and vector (female Anopheles mosquito). It is believed that AgNPs will be a solution for the control of malaria. This review emphasizes the pros- and cons of existing antimalarial treatments and in depth discussion on application of AgNPs for treatment of malaria. The role of nanoparticles for site specific drug delivery and toxicological issues have also been discussed.

Nano-Silver Toxicity: Emerging Concerns and Consequences in Human Health

Silver nanoparticles are used in diverse applications due to their unique properties, and thus are rapidly becoming part of our daily life. Silver nano-based products like wound dressings, cosmetics and antimicrobial coatings are now available in the market. However, little is known about their biodistribution and toxicity. The present chapter focuses on the risk associated with the use of silver nanoparticles, route of exposure, and different toxic effects of silver nanoparticles on different systems like nervous system, immunological, respiratory and reproductive systems. Developmental defects, genotoxic effects and toxicity at the microbial level have been reviewed and discussed.

Nanosilver: an inorganic nanoparticle with myriad potential applications

Abstract Bionanotechnology is the field dealing with the synthesis and application of different nanomaterials. Nanoparticles usually form the core of nanobiomaterials. For the past decade, a variety of inorganic nanoparticles have been newly created to provide superior material properties. Nowadays, synthesis of nanoparticles is the area of interest due to their physical, chemical, optical, electronic properties, and most importantly their larger surface area-to-volume ratio. Synthesis of inorganic nanoparticles is done by various physical and chemical processes, but biological route of synthesis is gaining more importance due to their eco-friendly nature. Bioactivity of nanoparticles broadly involves the wide range of nanoparticles and their biological application. They have been used as new tools not only for investigation of biological processes but also for sensing and treating diseases. In this respect, they are appearing to be novel antimicrobial agents even against drug-resistant microorganisms. On the other side at higher concentration, they show toxicity to the humans and ecosystem. Therefore, in the present review, we have briefly described the synthesis of different metal nanoparticles by different approaches mainly paying attention to their biosynthesis, antimicrobial activity, and cytotoxicity. As silver nanoparticles are finding many applications among all of the inorganic nanoparticles, we paid special attention to them, too.

Potential Role of Biological Systems in Formation of Nanoparticles: Mechanism of Synthesis and Biomedical Applications

Nanotechnology is essentially related with the synthesis of nanoparticles of varying size and shapes. With the search of envi- ronment-friendly protocols for the synthesis of nanoparticles a diverse group of biological agents have been emerged. These biological agents are safe, eco-friendly and lead to green synthesis of nanoparticles. The present review focuses on the role of biological agent(s) towards the development of green nanotechnology, the applications of nanoparticles in different fields of science and technology, and also the toxicological effects of nanoparticles.

Nanotechnology based anti-infectives to fight microbial intrusions.

With the rise in human population across the globe especially in developing countries, the incidence of microbial infections are increasing with greater pace. On the other hand, available medication and therapies are found to be insufficient for the complete cure of such microbial infections due to the development of resistance against various antibiotics. Therefore, to cope up the menace of microbial infections and drug resistance, there is demand for new and compelling technology, which has the ability to impede these problems. Many research groups worldwide are finding a ray of hope in nanomaterials owing to their unique properties. In the present review we have discussed the reasons behind the development of new materials based on nanotechnology. It is mainly focused on pioneering studies on application of nanomaterials like carbon nanotube, fullerene, dendrimers, nanocomposite and metal nanoparticles in combating dreadful pathogens. Moreover, the concerns about their toxicity have also been discussed.

Toxicity of fungal-generated silver nanoparticles to soil-inhabiting Pseudomonas putida KT2440, a rhizospheric bacterium responsible for plant protection and bioremediation.

Silver nanoparticles have attracted considerable attention due to their beneficial properties. But toxicity issues associated with them are also rising. The reports in the past suggested health hazards of silver nanoparticles at the cellular, molecular, or whole organismal level in eukaryotes. Whereas, there is also need to examine the exposure effects of silver nanoparticle to the microbes, which are beneficial to humans as well as environment. The available literature suggests the harmful effects of physically and chemically synthesised silver nanoparticles. The toxicity of biogenically synthesized nanoparticles has been less studied than physically and chemically synthesised nanoparticles. Hence, there is a greater need to study the toxic effects of biologically synthesised silver nanoparticles in general and mycosynthesized nanoparticles in particular. In the present study, attempts have been made to assess the risk associated with the exposure of mycosynthesized silver nanoparticles on a beneficial soil microbe Pseudomonas putida. KT2440. The study demonstrates mycosynthesis of silver nanoparticles and their characterisation by UV-vis spectrophotometry, FTIR, X-ray diffraction, nanosight LM20--a particle size distribution analyzer and TEM. Silver nanoparticles obtained herein were found to exert the hazardous effect at the concentration of 0.4 μg/ml, which warrants further detailed investigations concerning toxicity.