Magnetosome medicine: Using magnet-sensing bacteria to treat disease

in #steemstem6 years ago (edited)

Though I love the Steemit platform, one gripe I have with it is that good articles get buried just as fast as bad ones. @SteemSTEM has done some amazing efforts in getting quality science posts recognized, but even with their efforts the best posts will fall into obscurity after a week. I’ve mostly ignored this issue, but while I was doing some background research into this article’s topic (Magnetotactic bacteria!), I found a few articles on the subject had already been posted. Both articles were well written and relatively recent. I thought it would be a shame to either ignore or just passively cite them so I thought I’d try to springboard my post off of them. Rather than give a lengthy introduction on the topic, I’m going to give a brief overview and highlight the quality work done by past Steemians. This will give me more time to focus on exciting developments in the field and might encourage you dear readers to give a second look to some forgotten Steemit posts.

Magnetotactic Bacteria

This post is inspired by a fascinating type of microbe that moves along magnetic fields. These organisms are called magnetotactic bacteria and use the earth’s magnetic field to facilitate navigation (1). A March 2018 post titled Microbial World #8 Bacteria Synthesizes Nano-Sized Compasses to Navigate using Earth's Geometric Field from @vinamra gives a great overview of just how and why these unusual creatures function.

A magnetotactic bacteria with several magnetosomes aligned along a magnetic field. (2)
In brief, magnetotactic bacteria gather environmental iron and use it to create small magnetic particles called magnetosomes. These magnetosomes function as tiny compasses, orienting along magnetic fields, and allow bacteria to orient themselves as well. The formation of the magnetosome has been the subject of intense study.

@micro24 has covered some of this work and comprehensively shows that they form within internal compartments in his article Compartmentalization gives the property of sensing Magnetic Field in Bacterial Cell (helps in movement). Please give that a read if you want more info.

I’m always interested in the benefits basic research can give us, so after reading the articles from @vinamra and @micro24, I was curious as to whether investigations into these unusual organisms have yielded useful applications. @micro24 mentioned some water purity applications in his post, but the references he cited were a bit outdated so I looked through the modern work in the field. It didn’t take long for papers describing magnetosome-based medicine to catch my eye.

Treating disease with magnetosomes

It turns out that magnetosomes have a lot of applications for human health. A few of the most prominent are specialized MRI imaging, delivering drugs to a specific location, and Magnetic Hyperthermia (using magnets to apply intense heat) (2):

MRI Imaging:

Magnetic resonance imaging, more commonly known as MRI, is a common technique doctors use to look inside the body (3). In brief, organs and tissue are subject to high magnetic fields and hydrogen atoms within the body absorb and emit tiny amounts energy from these fields that can be visualized as an image.


Magnetosome labeled Cardiomycetes visualized by MRI (4).
Magnetosomes, being actual magnets, show up very strongly on an MRI image. They’re also non-toxic because they’re made through an entirely natural process without using harsh chemicals. For these reasons, magnetosomes are very effective at tracking specialized cells within the body. In one recent study, scientists were injecting cardiomycetes, heart repairing cells, into mice with heart disease.

They wanted to track the cells they were injecting into the body so they added magnetosomes to the cardiomycetes prior to injection (4). When they viewed the mice under an MRI, they werw able to see the magnetosomes had clustered around the heart indicating that the cardiomycetes were functioning as expected. This application is already quite far along as companies offering magnetosome labeling products have already popped up (5).

Drug Delivery:

The idea behind magnetosome-based drug delivery is to focus treatment at a specific site in the body to maximize effectiveness and eliminate side effects. This is especially useful for cancers where the disease might be localized to a specific organ, but simply injecting an anti-tumor drug will spread that drug throughout the whole body. Magnetosomes have proven to be a useful way to solve this problem. Anti-tumor Drugs are attached to magentosomes and injected into the body. Strong magnets are then placed near the tumor and the majority of injected magnetosomes will aggregate near the magnet.

Overview of using magnetosomes as a drug delivery system. Adapted from (8).
The image on the left gives a succinct overview of this process. It’s an attractive method of treatment because it is both non-invasive and doesn’t require any specialized equipment beyond some powerful magnets. Creating sufficient quantities of magnetosome-linked drugs efficiently is probably the biggest obstacle in fully implementing this.

Although multiple studies have shown promise on developing this into an actual treatment for patients (6, 7), I haven’t seen many clinical trials suggesting that this kind of treatment is still a few years off at best.

Magnetic Hyperthermia:

This is by far my favorite use of magnetosomes as medicine because it’s the perfect trifecta of being really cool, fairly easy to explain, and super fucking cool. This type of treatment is based on the idea that cancerous cells can often be killed with heat, which is referred to as hyperthermia therapy (9. Different types of this therapy have been around for some time, but its always been limited by the fact that heat will kill non-cancerous cells too. Researchers have been looking for an effective way to localize the heat to minimize side effects and magnetosomes might just be the answer. Not only can magnetosomes be concentrated on a tumor with magnets, but they can also be heated by applying an alternating magnetic current. The alternating current switches at a very high frequency which vibrates the magnetic particles fast enough to generate heat. Not only does this technique ensure that only the tumor is heated, but it also allows for exquisite control over how hot the region can get. Many studies focus on maintaining the temperature at 42 oC which isn’t strong enough to directly damage cells, but often generates a heat shock response that results in apoptosis of cancer cells. The diagram below explains how this can work in a mouse model.



Using magnetic hyperthermia to treat cancer in mice (2).

Magnetic hyperthermia is particularly attractive for treating glioblastoma, an aggressive and common form of brain cancer with no known cure (10). Preliminary studies show it to be quite effective in mouse models, and clinical trials are underway.

One thing to point out with these applications is that magnetosomes are simply used as a small magnet. In theory, researchers should be able to use any magnetic nanoparticle for this function. However, magnetosomes show clear advantages in practice because they are 100% naturally created. They don’t require toxic organic chemicals for synthesis and can be easily accumulated by growing magnetotactic bacteria. Many studies are devoted to finding the best way to cultivate these types of bacteria to maximize magnetosome production (11). I wouldn’t be too surprised if we start seeing magnetosome-based treatment sometime in the next decade, but I expect some strong pushback from overzealous Insane Clown Posse fans.



Moving magnetosomes forward

The above applications cover the major uses for magnetosomes in medicine, but they have plenty of applications in other fields. If anyone is particularly interested in this topic, feel free to continue this work. You could talk about using them for bioremediation, making really tiny compasses, or proving flat earthers wrong. You’d definitely get an upvote and a resteem from me for the effort. Again I’d like to give a big thanks for the introductory posts on this topic by @vinamra and @micro24. They’ve been very helpful in allowing me to focus on modern magnetosome medicine rather than rehash work that’s already on the platform.

References

(1) https://en.wikipedia.org/wiki/Magnetosome
(2) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4126476/
(3) https://en.wikipedia.org/wiki/Magnetic_resonance_imaging
(4) https://www.nature.com/articles/srep26960
(5) http://www.bellbiosystems.com/Products/Magnelle-Powering-
(6) https://www.cancerletters.info/article/S0304-3835(07)00407-7/abstract)
(7) http://www.mdpi.com/1996-1944/6/9/3755/htm
(8) https://link.springer.com/article/10.1007/s13204-013-0216-y
(9) https://en.wikipedia.org/wiki/Hyperthermia_therapy
(10) https://www.tandfonline.com/doi/abs/10.1080/02656736.2018.1430867
(11) https://www.sciencedirect.com/science/article/pii/S0928493115304926

Images

All images were taken either directly from the publication referenced or labeled for reuse on Google Images. If any image owner has an issue with this article, please contact me and I will address the issue.

Sort:  

They’re also non-toxic because they’re made through an entirely natural process.

Green mamba venom is made through an entirely natural process as well. ;-P

Jokes beside: Great article. I like the idea of taking up previous posts and expanding their scope.
Do you have any idea when there'll be human data on magnetosome therapy around? The animal studies were published ~5-10 years ago, from what I saw.

Its hard to say. Some clinical trials have been completed (http://www.journalrcr.org/article.asp?issn=0973-0168;year=2016;volume=7;issue=1;spage=13;epage=17;aulast=Shetake), but I'd guess that its still a few years off as these trials are few and far between.

It was a pleasure reading this well-written article. I really liked the idea how this technique can be used to kill off cancer cells while leaving the surrounding tissue intact. It is obvious that once properly developed, the technology will significantly increase the average lifespan of humans and to be honest, this is only good news for long-term cryptocurrency investors xD

That's great to hear!

First of all, when I think about writing an article I do a prior search to see if it was covered before and how well. If only the basics were covered then I expand on it, citing the initial author and putting the link in context.

Second of all this is how engagement works, prior author wrote something he is passionate about and you can bring his attention to your own work, verifying and approving it.

Everyone should learn from you. And I want to see more people commenting and bringing their attentions to the subject being discussed, especially if they have something to say about it :P

As for your article, the subject is very interesting and covers something that I had little to no experience about. Now I know a little and I will wait for more details and results :D

Thanks! Based on the positive response, I'm definitely going to continue referencing past Steemit articles. Glad I can help with engagement in some way as I know its an ongoing issue with SteemSTEM.

Really an interesting one,
Yeah, these magnetosomes are pretty interesting as the small particles present in these microbes proposes a wide applicability in the biological world. Sometime back I got an idea also related to these magnetosomes to write a project in the course work, may be I will write a project on it in future but still a lot to work on that, as it was just an idea.
Definitely, you may be seeing these in a very near future being used is diagnosis treatment and all.
and thanks for mentioning my article :)

Let me know if you do write a project on it and thanks for writing the original article! It helped me bypass the intro stuff and focus on current literature.

I’m always interested in the benefits basic research can give us

Just last night I was watching this ... you'll like the part from 3:41 to 4:34


Fascinating and promising stuff in your article!

Thanks for sharing. Sometimes it feels like 1000 guy's discoveries leads to 10 inventions that leads to one machine, but it goes to show that basic research has a purpose.

A science article which did not glaze my eyes - well done and thanks!

I love learning about new discoveries and you set it out in a way that even I could understand.

Thanks! Glad you liked it.

I do remember reading the previous article by @micro24 about magnetotactic bacteria and thinking it was pretty cool. Love your example of Magnetic Hyperthermia. The unusual nature of cancer seems to require a lot of different and creative ways of dealing with it, heating up a lot of tiny little magnets is the best I have heard yet.

Magnetic Hyperthermia is that rare idea that manages to be fairly simple and really creative at the same time. I hope it becomes a useful treatment.

This is pure science in action....waoooooo
I must say i am really overwhelmed with this

It definitely combines a lot of scientific disciplines and a unique niche in nature to advance the field. Thanks for the comment!

Congratulations @tking77798! You have received a personal award!

1 Year on Steemit
Click on the badge to view your Board of Honor.

Do not miss the last post from @steemitboard!


Participate in the SteemitBoard World Cup Contest!
Collect World Cup badges and win free SBD
Support the Gold Sponsors of the contest: @good-karma and @lukestokes


Do you like SteemitBoard's project? Then Vote for its witness and get one more award!

Hi @tking77798!

Your post was upvoted by utopian.io in cooperation with steemstem - supporting knowledge, innovation and technological advancement on the Steem Blockchain.

Contribute to Open Source with utopian.io

Learn how to contribute on our website and join the new open source economy.

Want to chat? Join the Utopian Community on Discord https://discord.gg/h52nFrV

Coin Marketplace

STEEM 0.19
TRX 0.14
JST 0.030
BTC 64535.04
ETH 3462.08
USDT 1.00
SBD 2.49