We make polysaccharide nanoparticles for cancer treatment, they are efficiently transported into the cancerous cells even against concentration gradient, but they get stuck in endosomes / lysosomes, how to force them out? Nanoparticle diameter: 20-100 nm, depending on technology. Composition: polysaccharide (biodegradable-biocompatible, safe). Room temperature synthesis in water so we can encapsulate proteins, drug is covalently bound and released slowly. What type of drug shall we choose, we can use multiple drugs with synergetic effect, we can encapsulate proteins, RNA, various drugs that are normaly unable to pass cell membrane. We are open for cooperation.
How about combining your nanoparticles with Photodynamic Therapy? This works well for drugs such as doxorubicin, which also get sequestered into lysosomes. PDT disrupts the cellular membranes and allows these drugs to leak back out into the cell.
I'm also open to collaboration on this.
How about combining your nanoparticles with Photodynamic Therapy? This works well for drugs such as doxorubicin, which also get sequestered into lysosomes. PDT disrupts the cellular membranes and allows these drugs to leak back out into the cell.
I'm also open to collaboration on this.
In cell cultures we find that attaching cell penetrating peptides to our nanoparticles (gold) leads to free particles in the cytosol and even in the nucleus. This may be easy to try for your system, and it may work.
Look at the buffering capacity of your nano ps. cationic lipids will boost the lysosomal exit but it is conditional. There are various proteins involved on this whole process. Please refer to gaurav sahay's paper on nano particles. I hope this would help.
You could use drugs that burst lysosomes, such as GPN (glycylphenylalanine β-napthylamide). Bursting lysosomes can precipitate cell death, so you will have to distinguish between the effects of GPN treatment alone and cells with your particles + GPN treatment. If your particles were preferentially taken up by cancerous cells then anything that compromises the integrity of the lysosomal membrane, or blocks autophagosome formation, would presumably be of great value.
have you considered radiochemicals? no need to egt them out of the lysosomes in the first place. alpha emitting may be most attractive, but for a proof of concept 3H may be the simplest way.
check out fusogenic peptides, if you are using a sugar polymer you may be able to conjugate to surface, EDC coupling or load these short peptides inside your particle. They facilitate endo lyso escape, I know a group who has had good luck with them although the conjugate to surface of particle. But if you encapsulate them, as the particle disolutes in the lyso/endo, these peptides may do the job for you
Good luck!
cyclic RGD on the surface
check this:http://onlinelibrary.wiley.com/doi/10.1002/anie.200800357/full
Many if not most cancer cells have phagocytic properties that assist in obtaining the products needed to sustain themselves and reproduce. I suggest that you add to the system a small amount of plasma membrane or homogenate from a normal counterpart cell and this should be phagocytosed. This should result in the acidification of the phagolysosome and hence, the drop in pH may cause the release of the cytotoxic agent from its encapsulated prison that is if the agent is sufficiently lipophilic and can diffuse from the phagolysosome and reach its intended target. (Suggest the free following article for background, etc:
Engi H, Gyémánt N, Ohkoshi M, Amaral L, Molnár J. Modelling of tumour--host
coexistence In vitro in the presence of serine protease inhibitors. In Vivo. 2009
Sep-Oct;23(5):711-5. PubMed PMID: 19779105.
Just a wild thought!
Classically chloroquine is used to get things out of endolysosomal system. For example plasmid DNA transfections where chloroquine helps to get the DNA out of endolysosomal system to cytoplasm and then to nucleus (Ref: DEAE dextran transfection protocol in the book current protocols series). Hopefully chloroquine could help to solve your problem and may boost your anticancer approach...!!
Photochemical internalization (PCI) could be a good alternative for you. We (Prof. Kristian Berg lab) developed the technology based on photodynamic therapy (PDT, as Jon mentioned). Review: https://www.researchgate.net/publication/45091527_Photochemical_internalization_provides_time-_and_space-controlled_endolysosomal_escape_of_therapeutic_molecules?ev=prf_pub
Use amphiphilic photosensitizers that over night localize to the membranes of endosomes and lysosomes. Light activation of the photosensitizer results in ROS-formation and subsequent lipid peroxidation and rupture of the membranes which leads to endosomal escape of sequestered molecules. This will provide time and space-controlled drug delivery.
Regarding intracellular transport of nanoparticles: Check this review in Nano Today by Tore-Geir Iversen: https://www.researchgate.net/publication/241121237_Endocytosis_and_intracellular_transport_of_nanoparticles_Present_knowledge_and_need_for_future_studies?ev=srch_pub
Article Photochemical internalization provides time- and space-contr...
Article Endocytosis and intracellular transport of nanoparticles: Pr...
Coupling the drugs to hydrazone (pH-sensitve) or for example to a GFLG (Cathepsin sensitive) linker is possible. Those linkers are used in pHPMA drug carriers.
Look to nature for pathogenic peptides that aid endosomal lysis and escape and then add that to your nanoparticle design. If you have a biological NP then you can add it to the plasmid, if synthetic NP then perhaps it can be carried along with your drug.
There is possibility to coat your NPs with PH-sensitive Polymer which increase its biocompatibility and let drugs easily release inside tumor cells.
Rozita I've heard of this type of modification before but wouldn't you think that would cause release into the tumor microenvironment (TME) and not necessarily inside of cells? Granted, drug release into TME is better than systemic delivery of a chemotherapeutic but the original question implied release within cells. Macropinocytosis will only get you so far if you deliver to the TME, these drugs are usually charged and would mostly be bounced by the plasma membrane.
Dear Rosita, Friends, we have almost 5 times higher concentration of nanoparticles in the tumor compared to other organs (mice, cervical cancer), any changes made to NP surface may decrease such perfect targeting.
Are you certain that it's a problem? Meaning, is your drug still bound to the gold particles once they're in the lysosomes? If they have done their job and the drug payload has been delivered, all the better for the cell to get rid of the interloper-- we assume you want to keep the cell alive? First, isolate the lysosomes and see whether drug is present compared to a cytoplasmic lysate.
Few things can remain free in the cytoplasm, and need to be recognized as friendly, so maybe coating the gold with melanin or actin or a recognizable substance that won't be vesicularized is a path. You don't want to "force out" the particles if the pathway has been triggered; you're already dealing with cancer, better to prevent another insult to the cell's metabolism.
It could be informative to study the fine structure at the EM level to understand how the particles are getting in. For example, my former work (Templeman and Wira) showed that investigators thinking that IgA was transported to the nucleus in vesicles had been using horseradish peroxidase as a tag, which created vesicularization. A test in vitro of responding cells could show this-- you might get in, but if it's the wrong door those vesicles are targeted for extinction in the ER and lysosomes, maybe along with your drug. Lysosomes are a result, not a cause.
So, consider: is your bypass of the cell membrane setting off the burglar alarm?
Dear Kristine, Friends, our nanoparticles are biodegradable polysaccharides constructs (60nm dia) tagged with fluorescent molecules and peptides. We want to deliver a deadly payload to the nucleus. Targeting in mice is perfect, NP are not recognized by immunological system, go straight were they are addressed. But You are right, we have to do our homework on cells and investigate it more deeply. What we see are fluorescent dots staying forever inside the cell, but it doesn’t have to be endosome. We have more experience with nanoparticles molecular engineering then with cells… Thanks.
Dear Tomasz, you can use fusogenic lipids such as dioleoylphosphatidylethanolamine, DOPE (as a label to your NP) for an efficient escape from endosome.
Related Ref: Breaking down the barriers: siRNA delivery and endosome escape. Monika Dominska and Derek M. Dykxhoorn. doi: 10.1242/jcs.066399.
A combination of oxidative stress can support cancer cell killing as they rely on glycolytic metabolism and have little peroxisomal and SOD. I have discussed that in several published papers, and especially in 2010 and this year, see Ultrastructural Pathology and other refs through PubMed.
If the lysosomes cannot digest the particles, they shall stay and create death, probably by poisoning the cells anyway.
Dear Friends, we will try fusogenic lipids. The problem is that nanoparticles are highly hydrophilic. They are made mostly of water – about 95%. That’s why they escape immunological system; they are able to circulate even few days looking for cancer cells. But lipophylic part, like fusogenic lipids will probably stay inside. Currently we work on the application of proton sponge. We also work on other methods of drug binding to increase drug release rate. I will talk about our problems with nanodrugdelivery, and hopefully about some succes, on CLINAM this year.
Cap the nano formulation on surface with some capping agent like chotisan etc will probably change the charge at physiological pH so it will not bind.Zeta potential of the polyacrylamide nano will guide you to get perfect tackling of problem
In fact , there are some additional issues with nano delivery in vivo: 1.)Most of the particles end up in liver and spleen, 2) local injections do not uniformly disperse the particles.
Recent advances in stem cell mediated nano-drug delivery looks promising
Tissue Eng Part A. 2013 Feb;19(3-4):508-18. doi: 10.1089/ten.TEA.2012.0244. Epub 2012 Nov 16.
Integration of a novel injectable nano calcium sulfate/alginate scaffold and BMP2 gene-modified mesenchymal stem cells for bone regeneration.
He X1, Dziak R, Mao K, Genco R, Swihart M, Li C, Yang S.
Nano Lett. 2009 Sep;9(9):3308-11. doi: 10.1021/nl901589y.
Targeted intracellular delivery of hydrophobic agents using mesoporous hybrid silica nanoparticles as carrier systems.
Rosenholm JM1, Peuhu E, Eriksson JE, Sahlgren C, Lindén M.
Abstract
Targeted nanoparticle-mediated intracellular delivery is demonstrated using two hydrophobic fluorophores as model drug cargo. The presented hybrid carrier system exhibits both cancer cell-targeting ability and capacity to retain a hydrophobic agent with subsequent specific release into the endosomal compartment. Furthermore, the incorporated agent is shown to be able to escape from the endosomes into the cytoplasm, making the particles promising candidates as carriers for targeted drug delivery for cancer treatment.
Dear Tomasz, I am curious about if you achieved any therapeutic benefit from using your NPs in tumor-bearing animals (if you performed such tests)? Endosomal localization is the usual fate of many NPs after contact with cancer cells. However, not in all cases this leads to worse therapeutic effect. For example, our tests of polycyanoacylate NPs loaded with epirubicin on lung cancer cells showed increased cytotoxicity despite the fact that NPs were localized in endosomes (at least after the first 6 h). However, the endosomal localization of the same NPs in cervical cancer cells (HeLa) resulted in diminished cytotoxicity. Intriguingly, it appears that the cytotoxicity of NPs may depend also on the type of cancer cells.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology