There are many studies on iron NPs but - interestingly- not much about what happens when they are internalized by cells. On one hand, in cell tracking applications, NPs should stay inside the cells long enough to serve for the purpose. On the other hand, it needs to be safely eliminated (or degraded?) at one point. What type of modifications on NPs would be needed to handle these two requirements?
I opened up this discussion to hear about insights of the in vivo process. Please let me know if you can add up.
Hi, Dear Nihan
Actually, it depends on nanoparticle sizes. Nanoparticles which are smaller than 50 nm are excreted through the kidneys. Since, they are useable only for cell death aims (totally called apoptosis), they will finally come out from the cells and enter the body's exhaust ducts.
Good luck
Dear Nihan
Your question is a fundamental one for nanomaterials used in nanotherapeutics and theranostics. In fact, one of the most important reasons why nanomedicines have had only a limited success so far is that there is no reliable and proven strategy to ensure the safe removal (either by catabolism or by excretion) of nanomaterials from the body (blood/cells/organs). Some nanomaterials (eg. liposomes, lipid micels, chitosan, dextran, few polymers like PLGA) can be broken down by enzymes and other catabolic mechanisms. But most others (gold, silver, SPION, MIPs, QDs and several others) cannot be metabolised. If the particles are very small (eg. carbon dots), they will pass through glomeruli and excreted in the urine. But I am not sure if Reza's suggestion that particles up to 50nm can be excreted in the urine is entirely accurate. Immunoglobulins are 10nm in size and they cannot be excreted in the urine. It is likely that larger particles are taken up by reticuloendothelial cells and retained in spleen, liver and lymph nodes.
Best wishes
Siva
In this context in 2016 an interesting work was published by Chiappi and co-workers. DOI:10.1186/s12951-016-0170-4
In this work the authors study SPIONs inside a cancer cell line using different advanced microscopy techniques. This nice work seems to reveal continuous transfer of the internalized SPION from the plasma membrane to a zone close to the cell nucleus.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanoparticle Research