request for protocols...

derek27

hello all.
i'm currently working on a number of hydrogels that have potential to be used as oral drug delivery vehicles for delicate biological agents such as insulin, which currently requires parenteral administration.
after spending an entire evening googling to no avail, i'm posting to enquire if anybody can direct me to a site online where i may be able to find protocols for all or any of the following cytotoxicity assays:

MEM elution cytotoxicity assay
Direct contact cytotoxicity assay
Agar diffusion/Agarose overlay assay

and pdf format MSDS's for all or any of the following compounds:

NVP
PVP
PAA
NIPAAm
PNIPAAm
polyethyleneglycol dimethacrylate

any help would be greatly appreciated.
derek

DrIndy

Sounds interesting, do you hope this can be absorbed in the gut? How would it bypass the lytic enzymes of the small intestine?

I hope a biochemist on boards can be of further assistance to you in your specific inquiry.

John

This is the only thing I could find which may or may not be of much help.

Link

Panserborn

Hi Derek

I use a clonogenic cell viability assay if thats of any use to you. I also use Trypan Blue, M.T.T. and X.T.T. cell survival assays. I use all these assays on human immortalised cells to examine the effect of chemotheraputic drugs on human DNA damage responses. If you reckon these would be of any use to you let me know and I'll send you the protocols.

www.sigma.com and www.msds.com are good for MSDS sheets and http://www.scienceboard.net/resources/protocols.asp is pretty good for protocols.

Hope this helps!

John

Panserborn wrote:

and http://www.scienceboard.net/resources/protocols.asp is pretty good for protocols.

That's a nice site, I'll be bookmarking that.

Capt'n Midnight

http://physchem.ox.ac.uk/MSDS/
not in pdf format , but plain text is so much easier to read.

also check up on synonyms of the substrates used


http://physchem.ox.ac.uk/MSDS/PO/polyethylene_glycol_dimethacrylate.html
not very informative - A real question - are you using commercial gels (I'd guess are safe or they will supply MSDS) or are you making them your self (neurotoxins - I knew a postgrad that no feeling in the tips of his fingers ) ?

Panserborn

Capt'n Midnight wrote:

or are you making them your self (neurotoxins - I knew a postgrad that no feeling in the tips of his fingers ) ?

This is true. We use polyacrylamide and after putting her finger into a splash of it (thought it was water) a postgrad in our lab lost feeling in her finger for a few days!

derek27

John2 wrote:

This is the only thing I could find which may or may not be of much help.

Link

thanks mate. that's pretty much all i need to know about that one.

derek27

Capt'n Midnight wrote:

http://physchem.ox.ac.uk/MSDS/
not in pdf format , but plain text is so much easier to read.

also check up on synonyms of the substrates used


http://physchem.ox.ac.uk/MSDS/PO/polyethylene_glycol_dimethacrylate.html
not very informative - A real question - are you using commercial gels (I'd guess are safe or they will supply MSDS) or are you making them your self (neurotoxins - I knew a postgrad that no feeling in the tips of his fingers ) ?

thanks for the links. we are not using commercial gels. they are original, and we know the polymers themselves are non toxic. however, the residual monomers are toxic, but we are working on that. but the most important concerns are the crosslinking agents that are being used in the gels... hence, the elution test is of critical importance.

to answer someone elses question in this thread (about avoiding degradation by lytic enzymes)... the gels are highly pH sensitive and have been configured to undergo a dramatic transformation (swelling... which allows diffusion of the encapsulated agent being delivered) at a specific site in the GIT where no enzymes exist that might inactivate the agent (insulin being the goal of our research). many other companies are approaching this in a similar manner, but our team of polymer engineers have developed one of the most promising hydrogels for this application so far!

John

derek27 wrote:

to answer someone elses question in this thread (about avoiding degradation by lytic enzymes)... the gels are highly pH sensitive and have been configured to undergo a dramatic transformation (swelling... which allows diffusion of the encapsulated agent being delivered) at a specific site in the GIT where no enzymes exist that might inactivate the agent (insulin being the goal of our research). many other companies are approaching this in a similar manner, but our team of polymer engineers have developed one of the most promising hydrogels for this application so far!

That sounds really cool! Good luck with it.