blending thermosensitive polymers with ph sensitive polymers for drug delivery

issac newton

i am interested in discussing about the pros and cons of having a vesicle of ph sensitive polymer (with drug to be delivered inside it), inside a vesicle of thermosensitive polymer for drug delivery. This gives us dual control capabilities that is temperature and ph based trigger mechanism.things i need to know about this are

1. is this method a novel approach for drug delivery, for a disease which needs a local site and ph change for drug release.

2. the ph sensitive polymer works based on feedback approach like the release of drug is based on ph change in the system.external triggering is involved for temperature change.

3. what are the difficulties in design of such drug delivery approach.

4. can i use this method specifically for some disease preferably(like some particular cancer demanding temperature and ph conditions) ?

thank you all.

chill_factor

does a pH sensitive polymer even exist that would exhibit physical changes on a useful timescale?

gravenewworld

Oh yes.

Dendrimers:

http://scholar.google.com/scholar?q=...ed=0CDQQgQMwAA


Many other types of nanoparticles are supposed to be designed to degrade or release as they become encapsulated in endosomes, which have a lower pH.


I imagine difficulty of design for something like the OP is talking about is trying to maintain zero order release kinetics, which is always a challenging issue with nanoparticles for drug delivery. Even if that is solved, the next problem is that many nanoparticles have problems with forming aggregates.

gravenewworld

Yes, you could use it for cancer. Cancer cells are more sensitive to heat, so if you had a thermosensitive polymer, you could target cancer cells with heat, and they should only die as opposed to normal cells/tissue. Then you could have release of your anti-cancer drug to kill off any remaining cancer cells. I guess that's what you're thinking about? Another issue is making sure your polymers themselves are not toxic, which is always another big issue.