Nanotechnology-based promising strategies for the management of COVID-19: current development and constraints.

INTRODUCTION: COVID-19 pandemic has been declared as a global emergency by the World Health Organization which has mounted global pressure on the healthcare system. The design and development of rapid tests for the precise and early detection of infection are urgently needed to detect the disease and also for bulk screening of infected persons. The traditional drugs moderately control the symptoms, but so far, no specific drug has been discovered. The prime concern is to device novel tools for rapid and precise diagnosis, drug delivery, and effective therapies for coronavirus. In this context, nanotechnology offers novel ways to fight against COVID-19. AREA COVERED: This review includes the use of nanomaterials for the control of COVID-19. The tools for diagnosis of coronavirus, nano-based vaccines, and nanoparticles as a drug delivery system for the treatment of virus infection have been discussed. The toxicity issues related to nanoparticles have also been addressed. EXPERT OPINION: The research on nanotechnology-based diagnosis, drug delivery, and antiviral therapies is at a preliminary stage. The antiviral nanomedicine therapies are cost-effective and with high quality. Nanoparticles are a promising tool for prevention, diagnosis, antiviral drug delivery, and therapeutics, which may open up new avenues in the treatment of COVID-19.

Curcumin and curcumin-loaded nanoparticles: antipathogenic and antiparasitic activities.

Introduction: Curcumin is an important bioactive compound present in Curcuma longa, and is well known for its bioactivities such as anti-inflammatory, anticancer, antimicrobial, antiparasitic and antioxidant activity. The use of curcumin is limited owing to its poor solubility in water, fast degradation, and low bioavailability. This problem can be solved by using nano-curcumin, which is soluble in water and enhances its activity against various microbial pathogens and parasites.Areas covered: We have reviewed curcumin, curcumin-loaded nanoparticles and their activities against various pathogenic microbes (antifungal, antiviral and antiprotozoal) and parasites, as curcumin has already demonstrated broad-spectrum antimicrobial activity. It has also inhibited biofilm formation by various bacteria including Pseudomonas aeruginosa. The antimicrobial activity of curcumin can be increased in the presence of light radiation due to its photo-excitation. Further, it has been found that the activity of curcumin nanoparticles is enhanced when used in combination with antibiotics. Finally, we discussed the toxicity and safety issues of curcumin.Expert opinion: Since many microbial pathogens have developed resistance to antibiotics, the combination of curcumin with different nanoparticles will prove to be a boon for their treatment. Moreover, curcumin and curcumin-loaded nanoparticles can also be used against various parasites.

Association of Silver Nanoparticles and Curcumin Solid Dispersion: Antimicrobial and Antioxidant Properties.

The last century, more precisely after 1945, was marked by major advances in the treatment of infectious diseases which promoted a decrease in mortality and morbidity. Despite these advances, currently the development of antimicrobial resistance has been growing drastically and therefore there is a pressing need to search for new compounds. Silver nanoparticles (AgNps) have been demonstrating good antimicrobial activity against different bacteria, viruses, and fungi. Curcumin (CUR) extracted from rhizomes of Curcuma longa has a variety of applications including antiinflammatory, antioxidant, and antibacterial agent. The association between silver nanoparticles and curcumin in a formulation can be a good alternative to control infectious diseases due the antimicrobial properties of both compounds. The objective of this work was to develop a formulation composed of a thermoresponsive gel-with antimicrobial and antioxidant properties due to the association of AgNps with PVP and PVA polymers. After AgNp synthesis, these were incorporated together with the previously prepared CUR/P407 (1:2) solid dispersion (SD) into a polymer dispersion of 20% P407 (thermosensitive gel). Our results showed that the association between the AgNps with CUR SD demonstrated good antioxidant activity as compared to the standard compound. Measures of MIC showed more efficacy against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) than for Gram-positive bacteria (Staphylococcus aureus). This association enhances antimicrobial activity against E. coli and P aeruginosa and added antioxidant value in formulations.

Broadening the spectrum of small-molecule antibacterials by metallic nanoparticles to overcome microbial resistance.

Now-a-days development of microbial resistancce have become one of the most important global public health concerns. It is estimated that about 2 million people are infected in USA with multidrug resistant bacteria and out of these, about 23,000 die per year. In Europe, the number of deaths associated with infection caused by MDR bacteria is about 25,000 per year, However, the situation in Asia and other devloping countries is more critical. Considering the increasing rate of antibiotic resistance in various pathogens, it is estimated that MDR organisms can kill about 10 million people every year by 2050. The use of antibiotics in excessive and irresponsible manner is the main reason towards its ineffectiveness. However, in this context, promising application of nanotechnology in our everyday life has generated a new avenue for the development of potent antimicrobial materials and compounds (nanoantimicrobials) capable of dealing with microbial resistance. The devlopement and safe incorporation of nanoantimicrobials will bring a new revolution in health sector. In this review, we have critically focused on current worldwide situation of antibiotic resistance. In addition, the role of various nanomaterials in the management of microbial resistance and the possible mechanisms for antibacterial action of nanoparticles alone and nanoparticle-antibiotics conjuagte are also discussed.

Biogenic fabrication of CuNPs, Cu bioconjugates and in vitro assessment of antimicrobial and antioxidant activity.

In the present study, the authors synthesised copper nanoparticles (CuNPs) by using extract of Zingiber officinale (ginger) and later the NPs were bioconjugated with nisin, which shows antimicrobial activity against food spoilage microorganisms. CuNPs and its bioconjugate were characterised by ultraviolet-vis spectroscopy, NP tracking analysis, Zetasizer, transmission electron microscopy analysis, X-ray diffraction and Fourier transform infra-red (FTIR) spectroscopy. Zeta potential of CuNPs and its bioconjugate were found to be very stable. They evaluated in vitro efficacy of CuNPs and its bioconjugate against selected food spoilage bacteria: namely, Staphylococcus aureus, Pseudomonas fluorescens, Listeria monocytogenes and fungi including Fusarium moniliforme and Aspergillus niger. Antimicrobial activity of CuNPs was found to be maximum against F. moniliforme (18 mm) and the least activity was noted against L. monocytogenes (13 mm). Antioxidant activity of CuNPs and ginger extract was performed by various methods such as total antioxidant capacity reducing power assay, 1-1-diphenyl-2-picryl-hydrazyl free radical scavenging assay and hydrogen peroxide assay. Antioxidant activity of CuNPs was higher as compared with ginger extract. Hence, CuNPs and its bioconjugate can be used against food spoilage microorganisms.

Biosynthesis of zinc oxide nanoparticles by petals extract of Rosa indica L., its formulation as nail paint and evaluation of antifungal activity against fungi causing onychomycosis.

Aim: The authors report the biological synthesis of zinc oxide nanoparticles (ZnO-NPs) from the petals extract of Rosa indica L. (rose). Its efficacy was evaluated against two dermatophytes: namely: Trichophyton mentagrophytes and Microsporum canis which cause onychomycosis. The activity of antibiotics against the tested dermatophytes was enhanced, when evaluated in combination with ZnO-NPs. Methods and results: The synthesised ZnO-NPs were preliminary detected by using ultraviolet UV visible spectroscopy, which showed specific absorbance. The ZnO-NPs were further characterised by nanoparticle tracking analysis (NTA), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction and Zetasizer. Moreover, nanoparticles containing nail paint (nanopaint) was formulated and its antifungal activity was also assessed against T. mentagrophytes and M. canis. ZnO-NPs and formulated nanopaint containing ZnO-NPs, both showed significant antifungal activity. The maximum activity was noted against M. canis and lesser against T. mentagrophytes. Minimum inhibitory concentration of ZnO-NPs was also determined against the dermatophytes causing onychomycosis infection. Conclusion: ZnO-NPs can be utilised as a potential antifungal agent for the treatment of onychomycosis after more experimental trials.

Antimicrobial peptides as natural bio-preservative to enhance the shelf-life of food.

Antimicrobial peptides (AMPs) are diverse group of natural proteins present in animals, plants, insects and bacteria. These peptides are responsible for defense of host from pathogenic organisms. Chemical, enzymatic and recombinant techniques are used for the synthesis of antimicrobial peptides. These peptides have been found to be an alternative to the chemical preservatives. Currently, nisin is the only antimicrobial peptide, which is widely utilized in the preservation of food. Antimicrobial peptides can be used alone or in combination with other antimicrobial, essential oils and polymeric nanoparticles to enhance the shelf-life of food. This review presents an overview on different types of antimicrobial peptides, purification techniques, mode of action and application in food preservation.

Curcumin nanoparticles: physico-chemical fabrication and its in vitro efficacy against human pathogens.

Curcumin is one of the polyphenols, which has been known for its medicinal use since long time. Curcumin shows poor solubility and low absorption, and therefore, its use as nanoparticles is beneficial due to their greater solubility and absorption. The main aim of the present study was the formation of curcumin nanoparticles (Nano curcu), evaluation of their antibacterial activity against human pathogenic bacteria and formulation of Nano curcu-based cream. We synthesized Nano curcu by sonication method. The synthesis of Nano curcu was assessed for their solubility in water and by UV-visible spectrophotometry. Further, the nanoparticles were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, nanoparticle tracking and analysis, and zeta potential analysis. In vitro antibacterial activity of Nano curcu was evaluated against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The cream containing Nano curcu was found to be effective against human bacterial pathogens and hence can be used for treatment of bacterial diseases.