#howmatters: ingredients for cancer drug delivery

Last week, Chobani Yogurt came out with a new ad cam­paign intended to pro­mote its “all-​​natural” ingre­di­ents list. A series of witty mes­sages revealed them­selves each time a hungry yogurt eater popped the lid on one of their Chobani100 yogurt cups.

Example: “Nature got us to 100 calo­ries, not sci­en­tists. #howmatters.”

Not sur­pris­ingly, sci­en­tists took issue with this por­trayal. They suc­cess­fully hijacked the hashtag and came out with an awe­some Twitter cam­paign of their own, pro­moting the pret­tier, not-​​so-​​scary side of science:

 

 

 

 

There are lots of things in nature…actually all of the things…that are made out of chem­i­cals but aren’t bad for you. Take spices. Here are a few scary chem­ical for­mulas and their pret­tier, less intim­i­dating versions:

Cap­saicin:

250px-Kapsaicyna.svgAKA, cayenne pepper:

Cayenne-Hero

 Crocin:

1280px-Crocin

 

AKA,  saf­fron:

saffron-160211682

and cur­cumin:

240px-Curcumin.svg

 

AKA, a chem­ical con­tained in turmeric…

SOG-18525-0

 …and a pow­erful anti-​​cancer agent.

And this, folks, is where our story really begins. As early as the 7th cen­tury, A.D., tra­di­tional Chi­nese and Indian med­i­cine was using turmeric (and by default, cur­cumin) as a treat­ment for var­ious con­di­tions including every­thing from the common cold to par­a­sitic worms. Later, lab studies have con­firmed that cur­cumin kills cancer cells grown out­side the body. A few animal studies have shown sim­ilar results, but in those cases there’s been a bit of a problem: cur­cumin is acidic, meaning it spits out hydrogen atoms when it goes into solu­tion. The internal envi­ron­ment of our bodies, on the other hand, is neu­tral, and that dis­con­nect makes it very dif­fi­cult to a) get the com­pound into the body in the first place, and b) once it’s in there, get it to where it needs to go: namely, the cancer cells.

New research from the lab run by pro­fessor Tom Web­ster, chair of the Depart­ment of Chem­ical Engi­neering at North­eastern, pro­vides a handy solu­tion to the cur­cumin conun­drum: a nanopar­ticle delivery system that “opens like a flower” under acidic con­di­tions, and then closes back up again under basic conditions.

The par­ticle was devel­oped by grad­uate stu­dent Run “Kanny” Chang, MS’14, and brings with it a couple of con­ve­nient advan­tages. First off, it’s able to encap­su­late drug com­pounds like cur­cumin in such a way that makes them more com­pat­ible with the internal envi­ron­ment of our bodies (as described above). But, addi­tion­ally, the sur­face of the par­ticle can be dec­o­rated with all sorts of spe­cial tar­geting moi­eties that make it seek and destroy cancer cells specif­i­cally, bypassing healthy cells. Once a par­ticle gloms onto a cancer cell, the cell engulfs it and wel­comes it into its inte­rior death chamber.

This is normal behavior: healthy cells do the same thing, it’s a process called “endo­cy­tosis” and it’s meant to take bad stuff out of the cel­lular envi­ron­ment and break it down into less toxic, biodegrad­able com­po­nents. How does endo­cy­tosis go about doing that con­ver­sion? Easy, it cre­ates a little pocket called a lyso­some, inside of which is a highly acidic vestibule. And what hap­pens to Chang’s nanopar­ti­cles in acidic envi­ron­ments? They open up like little flowers!

Since the nanopar­ti­cles can encap­su­late cur­cumin in their inner hydrophobic cores, they could deliver cur­cumin intra­cel­lu­larly and release drug in endo­somes and lyso­somes,” Chang said. “There­fore, com­pared to the free cur­cumin mol­e­cules, the anti-​​cancer ability of cur­cumin could be increased dramatically.”

In other words, when the cancer cell engulfs one of these nanopar­ti­cles and cre­ates a lyso­some around it, it’s simul­ta­ne­ously unleashing the very thing that will spell its demise!

How’s that for a nat­ural ingre­di­ents list? Yeah, I thought so.