It is a well documented fact that metallic or metal oxide nanoparticles are used as antimicrobial or antibacterial agents. However, there may be some bacterial (non pathogenic strains) systems which can benefit from the use of non-toxic nanoparticles. So, are there any type of nanoparticles which are non-toxic or non-inhibitory to bacteria, in general?
I am not an expert on nanoparticles.
Any suggestions are welcome.
Dear Shiladitya Ghosh ,
Can you please elaborate exactly what you are trying to do? Yes, There is a pool of decent publications revealing the bio-compatibility of nanoparticles(NPs)/nanomaterials. Most of them are published for cancer therapy, and functionalized with organic polymers, macromolecules, proteins, peptides and some charged and neutral ligands. In our research group, we use small organic molecules to functionalize Fe, Au, Ag, Cu and Ni etc NPs for a variety of applications including chemical, biological and microbial sensing and in the field of energy. In one of our project, we Functionalized Fe NPs with positively charged ligands to speed up their penetration in the bacterial(E.Coli) membrane. So, alternatively you can try negatively charged ligands to stop their penetration. Ligands with Carboxylate (-COO-) functionality at one end will suit you, the other end depends on the type of metal NPs, ideally -SH end for Au, Ag and Cu NPs and -NH2 and -OH end for Fe NPs.
Nanoparticles have variety of modes of action that results in cellular damage, the cheif of which being their ability to penetrate inside the cell due to their extremely small size, resulting in oxidative shock and ultimately leading to death of resulting cell. If the metallic nanoparticles are stable enough, all of them can be toxic to microbes as they all possesses size in nanoscale dimension.
Dear Dr. Hashmi,
Thank you so much for providing the clarification in such an easy way. So, I suppose that all metallic nano-particles at their native state are toxic to the microbes due to their small size and penetration capacity. Are there any modifications (chemical/charge induction) possible that can block their entry into the cells through the membrane pores/channels at the same time retaining their original function intact?
Regards,
Shiladitya
Not that I know of in particular. I am still a student with much to learn. I can help you with how they enter the cells and mechanism of their action but unfortunately I have no Idea about how to prevent that from happening.
In general, nanoparticles posses excessive surface energy and as such induce oxidative stress on the microorganisms. Thus, the idea would be to reduce the surface energy, for example via capping.
Dear Sir Andrei Burnin.
As far as my understanding goes, all the chemical and biological methods of nanoparticle synthesis involves two key steps i.e Reduction of the precursor metal salts and the capping of the resulting metal ions so, as such, capping of nanoparticles is already carried out. Sometimes, even the capping agents may as well be toxic and induce oxidative stress.
Mr. Hashmi explained in much details, not all the particles are cytotoxic for bacteria. Yeah there are ways to prevent them to letting inside the membrane, we can functionalize the surface of nanoparticles with variety of ligands to make them compatable. Mostly bacteria have negative charge on their surface, so by functionalizing negatively charged ligands wo may prevent their penetration to membrane. You may also functionalize the surfaces partially to retain the riginal functionality of the nanoparticles.
Best,
Abbas
Dear Dr. Abbas,
Thank you so much for providing the information. It seems that you have pointed out towards the scientific facts I am looking for. Entry of the nanoparticles inside the cells may be stopped through the surface modifications you mentioned.
Can you kindly share links of some relevant published articles on this field of study involving surface-modified nanoparticles that are biocompatible with some bacteria/microbe?
Regards,
Shiladitya
We manufacture both particles; ones that have Silver attached that will inactivate bacteria and other ,coated magnetite ,in which the metal is blocked from interfering with the bacteria. Our website is www.clemente-associates.com
Dear Shiladitya Ghosh ,
Can you please elaborate exactly what you are trying to do? Yes, There is a pool of decent publications revealing the bio-compatibility of nanoparticles(NPs)/nanomaterials. Most of them are published for cancer therapy, and functionalized with organic polymers, macromolecules, proteins, peptides and some charged and neutral ligands. In our research group, we use small organic molecules to functionalize Fe, Au, Ag, Cu and Ni etc NPs for a variety of applications including chemical, biological and microbial sensing and in the field of energy. In one of our project, we Functionalized Fe NPs with positively charged ligands to speed up their penetration in the bacterial(E.Coli) membrane. So, alternatively you can try negatively charged ligands to stop their penetration. Ligands with Carboxylate (-COO-) functionality at one end will suit you, the other end depends on the type of metal NPs, ideally -SH end for Au, Ag and Cu NPs and -NH2 and -OH end for Fe NPs.
I also acknowledge the answer of Andrei Burnin , Surface caping/functionalizing is the key to make any NPs bio/microbial compatible. ANd there are also some NPs which are not toxic eve without functionalizing, you may have a quick look on the synthesis of NPs by bacteria. https://www.omicsonline.org/open-access/biological-synthesis-of-metallic-nanoparticles-by-bacteria-fungi-and-plants-2157-7439.1000233.php?aid=31363
> http://onlinelibrary.wiley.com/doi/10.1002/anie.201001524/abstract;jsessionid=4DF41DBCA767A695C41436C2A8330878.f01t04
>
Dear Dr. Abbas,
Actually I am working on the development of a conceptual system where the NPs will need to get close to the microbial cells without killing or entering them.
Your suggestions and justifications have been very helpful in this regard.
Thank you for sharing your views.
Regards,
Shiladitya
You may go through the article..link given below. Hope it will help youArticle Sodium alginate and gum acacia hydrogels of zinc oxide nanop...
one main mechanism of antimicrobial action is release of heavy metal ions. The smaller the particles the higher the surface area releasing the ions. Therefore using nanoparticles, which do not release toxic ions like magnetite particles lower the potential for harming cells.
Dear Shiladitya Ghosh ,
Toxicity of nanoparticles depends on concentration of nanoparticle and to what extend its penetrating into bacterial cell wall
Hope it will help you
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructured Materials
- Nanoparticles