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Methanol toxicity in cell culture - (Jun/03/2009 )

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jakatta70 on Sep 3 2009, 09:29 AM said:

My project is a nightmare at the minute trying to find a suitable carrier for these drugs. Some drugs are very polar and will onyl dissolve in 3% DMSO. Problem is at this percentage the drug comes out of solution when incubated at 37C which ends up killing my cells as well.


Have you tried either of these?: increase the serum content (or dissolve the compound directly into serum); try one of the cyclodextrin family of carriers (this drastically alters the delivery kinetics but at least you end up delivering something).

-DRT-

DRT on Sep 4 2009, 12:46 AM said:

jakatta70 on Sep 3 2009, 09:29 AM said:

My project is a nightmare at the minute trying to find a suitable carrier for these drugs. Some drugs are very polar and will onyl dissolve in 3% DMSO. Problem is at this percentage the drug comes out of solution when incubated at 37C which ends up killing my cells as well.


Have you tried either of these?: increase the serum content (or dissolve the compound directly into serum); try one of the cyclodextrin family of carriers (this drastically alters the delivery kinetics but at least you end up delivering something).


Hi,

Dissolving the drug into the serum is an interesting idea. I will certainly try that. Could you tell me though why you think this might keep the drug in solution? Also if the polar drugs only dissolve in DMSO would you not expect the drug to be insoluble in serum? It is insoluble in DMEM media.

-jakatta70-

jakatta70 on Sep 5 2009, 01:31 AM said:

Dissolving the drug into the serum is an interesting idea. I will certainly try that. Could you tell me though why you think this might keep the drug in solution?


If it werenít for the carrier proteins in serum, my drugs would never get to where they are needed :blink:

-DRT-

DRT on Sep 8 2009, 12:40 AM said:

jakatta70 on Sep 5 2009, 01:31 AM said:

Dissolving the drug into the serum is an interesting idea. I will certainly try that. Could you tell me though why you think this might keep the drug in solution?


If it werenít for the carrier proteins in serum, my drugs would never get to where they are needed :)


Hi DRT,

I took your advice and tried dissolving some of my highly polar compounds into FCS. Unfortunately none would dissolve even after I applied 50-60C heat and/or vortexing for an hour. So I decided to try a 1:1 ratio of 100% DMSO + FCS. This produced an intense exothermic reaction which precipitated the protein content of FCS and turned the solution a dark cream colour. So I cant use this in my in vitro assays.

So what Im going to do is make a concentrated solution of my drugs in 100% DMSO and add x microlitres to my cell assay so that the final concentration of DMSO the cells are exposed to will be less than or equal to 0.5%. At this percent I havent been finding toxicity when using an LDH assay. Fingers crossed!

-jakatta70-

Good luck, sounds like it should work. I like your 'try it out and see' attitude. Are we allowed to know a bit more detail about your compounds?

-DRT-

DRT on Sep 9 2009, 01:30 AM said:

Good luck, sounds like it should work. I like your 'try it out and see' attitude. Are we allowed to know a bit more detail about your compounds?


Hi,

Im bound by a confidentiality agreement but I can say that they are extremely polar compounds with high molecular weights.

One of my supervisors (I have three unfortunately and two arent even biologists. They are chemists that havent a clue about the assays Im doing!) sent me a graph that a previous student had done with on drug in question. He had told me the drug reduces MMP-9 in vitro. I havent seen that and my n number is 3 while the other previous student only tried this assay once. Well, I get the graph yesterday and there is no MMP-9 reduction over a range of drug concentrations! lol! Maybe I should advise the supervisor to have his eyes (and head) examined!

-jakatta70-
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