Lipid Nanoparticles - How do they work - Structure of LNPs - LNPs in mRNA vaccine Pfizer/Moderna
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- เผยแพร่เมื่อ 10 ก.พ. 2021
- In this video, Dr. Aizaz from Medicovisual describes how Lipid Nanoparticles work and what is their structure.
Previously we have already discussed how mRNA vaccines work. The idea is to transport the mRNA of the spike protein of coronavirus into the cell. The cell will then create spike proteins and will train the immune system to recognize the Sars-CoV-2 from its spike protein.
The problem here is that a naked RNA cannot enter into the cell. And of course, without entry into the cell, the mRNA vaccine will never work. Furthermore, the RNA particles present outside the cell will be quickly degraded by the RNAses present in the extracellular environment.
To solve this problem, Lipid nanoparticles were created. These are incredibly small particles, measured at a nanoscale. [From your secondary school knowledge, you must be knowing that 1 nm = 10-9m]. These tiny lipid nanoparticles are made up of fat/lipids. They can keep the RNA safe from the RNAses and can faithfully transport the RNA inside the cell, into its cytosol.
But the question is why does mRNA, which is a type of RNA by the way, cannot, by itself, cross the cell membrane and enter into the cell? Why does it need external help from either a viral vector or a lipid nanoparticle?
The reason is that RNA [and DNA too] is negatively charged, because of the presence of negatively charged Phosphate ions attached with each of its structural subunits; nucleotides. So, it is the Phosphate ions that impart a net negative charge to the RNA and DNA.
Charged or ionic substances have a hard time crossing the cell membrane made up of lipid bilayer.
When surrounded by the lipid nanoparticle, RNA can cross the lipid-bilayered cell membrane as it becomes a lipophilic substance.
You can imagine it from a simple analogy. Let us suppose you want to a restricted area where only Police is allowed to go. Of course, you will be denied entry at the gate. [Think of the gate as the cell membrane].
You still want to go to that restricted area. You call your friend who is a police officer. You sit in his police van and then easily pass through the security checkpoint.
The same is happening here. Foreign RNA is not allowed to go inside, so it enters into this police van or LNP to cross the cell membrane.
After understanding why there is a need for a lipid nanoparticle. Let us now discuss what is it made up of and then will understand how it works.
Structure and components of LNPs
As discussed earlier, RNA is negatively charged. You must be aware of the fact that opposite charges attract. So, cationic lipids [positively charged ions] will attract and thus bind with the negatively charged [Anionic] RNA.
Cationic lipids contain an amine group head that has a positive charge on it. Along with that, it has legs made up of fatty acid chains, that are non-polar or non-ionic.
When such cationic lipids come across the RNA, they will obviously orient their charged [cationic] amine head towards the RNA and will orient the legs outward.
Permanently cationic [having a permanent positive charge] lipids are toxic and can disrupt the integrity of cell membrane [1]
To mitigate this problem, ionizable cationic lipids are used. These lipids are either neutral or slightly charged [cationic] at physiological pH. But in the lab, they create the vaccine at an acidic pH.[2] On acidic pH, the Proton or H+ ion quickly attaches with the amine head of the lipid causing it to acquire a positive charge. Due to this positive charge, it embraces and encapsulates the negatively charged RNA.
At physiological pH, as these ionizeable cationic lipids will become neutral, they may cease to embrace the RNA. So this particle is further surrounded by one or more additional layers of phospholipids. Thus RNA will still remain packed and protected inside the core of lipid nanoparticle.
They are mostly non-cationic structural lipids with some cationic lipids too embedded in between them, here and there.
Then there are some lipids, conjugated with a special molecule called PEG [Polyethylene glycol], that too are embedded into this outer layer. The outer layer of PEG prevents the aggregation or fusion of LNP particles with each other due to its steric hindrance [3]
Polyethylene glycol offers a steric hindrance and prevents the immediate take-up of these lipid nanoparticles by immune cells followed by their destruction. [3] Thus, it slows down the clearance of these LNPs quickly from the body.
PEGylation is reversible in such a way that LNPs gradually undergo de-PEGylation. PEG is gradually removed and the de-PEGylated LNP is then picked up by the cells gradually.
Cholesterol is also present interspersed in the spaces between the nanoparticles. It maintains the integrity and imparts the structure stability to LNP. Cholesterol, and structural phospholipids, forming the outer layer of LNP, are also called helper lipids
Website: www.medicovisual.com
Email: draizaz@medicovisual.com
Can you please give me reference of journal Or something from which u got this information
References
[1] Lipid-Based Nanocarriers for RNA Delivery. doi.org/10.2174/1381612821666150531164540.
[2] Guimaraes PPG, Zhang R, Spektor R, Tan M, Chung A, Billingsley MM et al. Ionizable lipid nanoparticles encapsulating barcoded mRNA for accelerated in vivo delivery screening. J Control Release 2019;316:404-17. doi.org/10.1016/j.jconrel.2019.10.028.
[3] Mui BL, Tam YK, Jayaraman M, Ansell SM, Du X, Tam YYC et al. Influence of Polyethylene Glycol Lipid Desorption Rates on Pharmacokinetics and Pharmacodynamics of siRNA Lipid Nanoparticles. Mol Ther Nucleic Acids 2013;2:e139. doi.org/10.1038/mtna.2013.66.
[4] Kulkarni JA, Cullis PR, van der Meel R. Lipid Nanoparticles Enabling Gene Therapies: From Concepts to Clinical Utility. Nucleic Acid Ther 2018;28(3):146-57. doi.org/10.1089/nat.2018.0721.
[5] Patel S, Ashwanikumar N, Robinson E, DuRoss A, Sun C, Murphy-Benenato KE et al. Boosting Intracellular Delivery of Lipid Nanoparticle-Encapsulated mRNA. Nano Lett 2017;17(9):5711-8. doi.org/10.1021/acs.nanolett.7b02664.
@@MedicoVisual thank you so much.........
@@MedicoVisual loved your explanation... Thank you...
@@rutujadhaware931 You are most welcome
@@MedicoVisual
Have you read the papers in 2019 by Ying Tam. Cheif Science officer of acuitas. The manufacturer of these LNP being used.
One paper states the PEGylated particles have a C14 "anchor"
I was very troubled to see that
Data is now showing that the lipids travel throughout the body in the days following the injection. Then they accumulate in such areas as the spleen and bone marrow. What is the explanation for this, will these lipids eventually break down or is this cause for concern?
I cant find any pharmacokenetic studies besides that one requested FOI fr japan
If those were not the same composition and size then the properties and pharmacokenetics may be different than the c 19 mrna vax
This is factually correct alex. They use platform approaches with similar lipid layers of gene therapies (siRNA) while not testing the actual product in any capacity.
This allows biodistribution and toxicity studies to be skipped.
Moderna VP of nonclinical studies went over this is a Labroots Webinar that was deleted in early 2020.
I screen recorded it, but nobody cares that every future mrna with an lnp will skip all trials.
@@zachocracyany source for your claims? thanks!
Only video on internet to explain this topic clearly.
Thank you 😊😊
Most welcome 😊
I’m trying to get answers to these questions:
do lipid nanoparticles themselves enter the nucleus and potentially cause harm to dna without being destroyed by the cells first?
How long do lipid nanoparticles take to be destroyed by cell and how do they take to leave the body?
I would also like to know and seems their replies to every other post but this one. 🤨
THIS IS EXACTLY WHAT I NEED TO KNOW...
And what do you know about lipid metabolism in general? 🤔
if you took it, then you ARE ‘the research’ ... for life.
You're great at what you do. Thank you so much for this!
What a great video! Thanks Dr.Azaiz!
Good explanation. I had no idea of LNP and was just trying to understand how RNA gets encapsulated and the chemistry behind it. Thanks
If the used LNP would be targeted, it would have components on its surface that would facilitate entry. There is no such component mentioned in any files from the FDA or the EMA as being part of the formulation. Ergo, unless proven otherwise, we can say those LNPs are untargeted.
Thank you for this very clear and easy to follow explanation. The visuals were very helpful, too.
Glad it was helpful!
I have been trying to work out if the LNPs are specific or non specific too, thank you for your research.
Many antivax stuff gets millions of views, but for some reasons the algorithm didn't favour this minilecture despite it being almost optimal in its content and style.. Sad things happen. Wish you good luck
I just discovered your channel, and I am irked that I hadn't found it sooner! Your videos are fantastic!
Wow, thank you!
@@MedicoVisual of course! I shared this video on my Facebook. Hopefully others will, too. People hear "nanoparticles" and freak out unnecessarily. Science communication is so important for public health!
Thank you for sharing. I concur. I think drug companies and government departments like CDC, FDA, MHRA should have created such inforgraphic content to educate the people about vaccines and COVID, in general. That would have drastically increased the public confidence and trust in public healthcare departments and immunization programs.
Fantastic illustration
I love the analogy of using the cop car to drive the RNA behind the enclosed area.
However, I need to be more clear about who’s or what is driving or controlling that lipid nanoparticle?
little tiny guys, we shrunk em so that we could engorge your balls with lipids
What did you mean by driving, controlling?
Hydrogel????
This is fantastic!! Thank you for your clear explanation.
You're very welcome!
Thanks Dr. Azaiz for the illustration! Very helpful. Were you able to get an update from the vaccine manufacturers in regards to the use of non-specific or ligand-specific LNPs? I’d imagine there would have to be some kind of specificity, otherwise these particles would be everywhere. Pls provide an update if u have one. Thanks!
Of course, no answer.
Pfizer never responded to my query
Dude. This video is incredible
Thank you so much
Excellent video, very informative! Thank you!
Very welcome!
Great lecture! Thank you!
Very clearly explaned lecture.Easily understandable by medical and related personals
Thank you
Thank you for your explanation. Your videos are perfect!
Glad you think so!
Really it was Great explanation sir, thank you so much for this vedio, stay blessed sir
You are most welcome
Very good video Dr Aizaz. Have you done any comparative analysis (Pros and Cons) of use of Liposome vs AAV as mRNA delivery tool.
Hi Dr Aizaz. It is a great video with lot of clarity. I am currently working on a article with this topic and I have a query. Do these lipid nanoparticles release the encapsulated mRNA in a sustained manner or mRNA are released rapidly once they enter the cell? In other words, are the LNPs long-acting systems or short-acting? Thank you.
Wonderfully explained
Thank you so much
Informative video thanks.
So nice of you
Loved your video!
So glad!
Very useful thank you very much!
Thank you very clear , very useful video ... continue
You are welcome
Exellent lecture about vaccine.
Thank you
Excellent
What if it ended up in exosomes? Exosomes are supposed to have immune functions. In that case could it get released and end up payload to other antigen presenting cells? I wonder if the RNA could cause failed recombination of SAR-CoV-2 RNAs since they have pseudouridine. If a variant is mutated a lot and not repairing well would it have to recombine with another RNA when it reaches the spike part on the negative strand. How might it influence recombination if it ended up bumping into a virion?
Have you found some literature about that?
There are so many theoretically possible routes for such particles. I wonder how many of them were studied in detail...
Thank you for the great video. Have you been able to glean details on LNP structures in the Covid-19 vaccines from the Moderna or Pfizer by reading their patents?
Not yet. Patents too do not explain anything about the specificity of LNP. if you or anyone reading this has any information about this, please share.
@@MedicoVisual do you know of any pharmacokenetic studies besines the FOI ones of the rats (im not even sure if those were the same size and composition) and size ect changes properties and i would assume pharmacokenetics
@@MedicoVisualwhat kind of toxic effects were evaluated for these two mRNA vaccines?
I'm more of a molecular biologist (basic research) so not very familiar with clinical trials/studies.
Thanks if you have any suggestions to read (ment for semi-laypeople) about my Q
What happened to charged particles after lipid was destroyed? Are they going to change cells' negatively, or positively charged?
Dr. Frankenstein lives.
Welcome to the future...
first time like this kind of Indian accent
Rationale and Application of PEGylated Lipid-Based System for Advanced Target Delivery of siRNA
Thaku so much for the useful information 👍👍🙏
Most welcome
Don’t buffers play a big part on how lpns function and also on codon optimization? I ask because Pfizer has updated their ingredient list a couple times and what they changed were buffers, they state it dosnt affect the function of vaccine at all, it only helps the shelf life of the vaccine.
I suppose codons are selected in a way not to introduce unwanted secondary structures...
There are many articles that I have seen in twitter and on other social network , About Placebo group, but I m not getting this that in case of virul infection ,placebo drug or injection work?
Sorry, I didn't quite understood your question. Kindly repharse.
@@MedicoVisual Sir I have read in a article ,in which it is written, people who have gotten placebo vaccine for trail are found to be infected of Covid19, so I am not getting is that in case of virul infection placebo vaccine work or not?
@@sktgenerous8838 Placebo means something that is not a drug or vaccine. For example: Plain salt water (Normal saline). It is used for comparison purposes.
Firstly, thank you for the clearly explained lecture. I have a question about the the LNP (specific or non-specific). Did you receive a scientific paper or jut a answer from Pfizer? If it's a paper, can you share it. Thx
Thank you for you appreciation.
I emailed Pfizer, BioNTech and Moderna but only Pfizer replied.
Apparently it isn't a journal article nor a tailored response to my question. It's a document explaining the mechanism of action without explicitly mentioning anything about the tropism [specificity] of the LNP. It maybe the excerpt from product label.
I have uploaded it on my Google Drive. You can read if you want to. drive.google.com/file/d/1g2wRLQ6GxFnVdtXqzv4yQn44uiQoS05F/view
P.S.: If you or anyone reading this come across a good resource answering my question. Please share it here.
@@MedicoVisual Thanks for the great video. So it seems the LNP are accumulating a lot in ovaries of lab rats, based on this study files.catbox.moe/0vwcmj.pdf
Thank you so very much for sharing this document. I will carefully read and analyze it. Can you please share the source of this document?
@@MedicoVisual as you said, they are non-targeted. As it’s an intramuscular injection, it is very likely that the LNPs end up in muscle cells and some other immune cells around the muscular area.
@@aprameyag4941 what if have muscle atrophy issues and not much fat or muscle mass. Can this be of concern and maybe better to have injection in buttox or thigh
How lipid nanoparticles can potentially affect brain functioning and behaviour.
I don't think that it can, but if you have any study that concludes so, please share.
@@MedicoVisual I somewhere read something about it
@@apuntes8883 If you find it again, please do share.
Rationale and Application of PEGylated Lipid-Based System for Advanced Target Delivery of siRNA
Front. Pharmacol., 20 January 2021
Sec. Translational Pharmacology
Volume 11 - 2020
I have a question - if you wanted to lyse this cell in the laboratory how would you go about degrading the LNP to release the mRNA?
Good question. Have you (l)earned an answer to it?
Why did not I hear this analogy when I had to enter Fort Zancudo in GTA
lol
Couldn't there be natural RNA we need that could be recognized as a threat when in fact it is needed for certain functions in the body? It seems there may be a chance these spike protein RNA pieces/codes could exist in other aspects of our cells. The same thoughts occur for the lipid makeup and positive and negative charges.
Why would cells recognize SINGLE STRANDED RNA as threat?
Do Not Get these arm candy's they are meant to remove you
Why do you think we want to share our lives with simple-minded doomsayers 😅?
I wondered how lipid nanoparticles distribution to cells. One cell has a limitation to uptake many RNA chains. When a flood of mRNA vaccine injection to muscle. All mRNA bombarded to muscle cells. Until cell rupture. And inflammation after that.
There is less mRNA in a dose of both mRNA vaccines than in 1-2 grams of most human tissue 😅
But the lipid ends up IN THE OVARIES! no RNA for me.
We are USA we have JandJ. DNA technology. Good for me
Do you think that adenovirus based vaccines are without problems 😅? Dream on...
Did Pfizer get back to you if it was specific or nonspecific
No. They never did.
What do you think about the trace of DNA in the NLP of mRNA vaccines?
I didn't study that. Please share relevant article(s), if you have.
@@MedicoVisual th-cam.com/video/IEWHhrHiiTY/w-d-xo.htmlsi=s7mf1dUvLT7Qz7yI
Welcome to creepy town... 👽it's how we role...
Very interesting. Obviously the covid vaccine was a huge failure and caused a lot of damage. Omicron was natures vaccine which ended the pandemic. Maybe more testing is needed.
Can mRNA vaccine change your NRA code ?
what is NRA?
@@MedicoVisual I mean RNA
@@imthefriend6463 No, body's RNA does not "change". A new piece of mRNA is temporarily added. Kinda like USB Drive.
@@MedicoVisual I tend to believe you, but this temporarily thing, what will make it go away ? its in its code to dissolve ?
@@imthefriend6463 Half-life of mRNA is few minutes only. [elifesciences.org/articles/32536#:~:text=The%20new%20measurements%20with%20our,min%20respectively%20(Figure%201C).]
It's very unstable molecule and is naturally destined to be destroyed very quickly. For the sake of argument, lets assume that it fails to be destroyed, then what happens? Simple! Immune system will destroy the whole cell anyways, thus everything inside the cell including mRNA will be destroyed too. Even if somehow immune system too fail to destoy the cell, the cell will be ultimately lost during regular cellular turnover. Even if it divides before dying, we, humans, don't have any mechanism to make copies of RNA. So, new cells will remain spike protein-RNA-free.
wrong.... this what a regular lipids are....
The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes.
your injected with a man made lipids
lipids are made of ++ fat covered by a plastics to trick the cell and enters the Cytoplasm.
Cytoplasm is the gelatinous liquid that fills the inside of a cell. It is composed of water, salts, and various organic molecules.
Water and fat don't mix .....
Wow. I never knew I was injected "Plastic" in the name of vaccine 🤣
@@MedicoVisual they use spinners and chemicals to replicate a lipids that are injected into cells... Your now genetically modified... read what normal lipids do.... Its how the fat got in or it would be rejected... its part of the polymer family peg.. varnish on your deck boat polymer or in bathroom silicon ... 3 years... - fat and water don't mix but the polymer will degrade ... UV sun react to polymer ... its just a man made lipids not sure how that is going to brake down in water salt .. one big lie...
@@MedicoVisual
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins.... Fat and water don't mix and nothing in the cell to consume it.. it would simple remain as new lipids... cell water is like ocean water sulfur salts where a virus enters and brakes apart as an invaders and the cell self destructs .... lipids run signals
@@julienbrunelle8496please learn some more science (no elementary school biology is not enough): also you can easily look up that peg is already part of decades old drug formulations... There were already hundreds of studies on LNPs even before the pandemic.... Look up those which use PEG and if you find any concern let me know. Thanks and cheers
@@julienbrunelle8496why do you think that your paranoic "understanding" has to do with anything in molecular biology?
Our cells already have mechanisms to take up and metabolize lipids, otherwise they would die.
FFFFFFF!!!!!! why does every scientific medical video have some guy with a terrible Indian accent.....
Why are you being racist?
@@MedicoVisual nothing is racist!!....I love Indians and Indian people.. In fact my commentary was noting the fact that many Indians are very smart and do a large percentage of medical and scientific videos!!! And people can be free to be racist or idiotic!! You gen z millennial think everything is racist... My comment is to keep you practicing English pronunciation.... So more people can enjoy the knowledge contained in yocanur medical video!!btw "Indian" is a nationality and not a "race" ...As a medical doctor you should know that!!! Furthermore, The ethnicity of most Indians is "dravidian". You should say ;:; that i am "rude"... Rude or "mean" are the correct words
@@sarahconner9433 L
@@MedicoVisualI would say after hearing lots of "English" speaking Hindi people, that your language skills are very adequate. And thanks for the video
oh my god - your comments, starting with the fffffffs was ALL KINDS OF RACIST. @@sarahconner9433