The Wide Angle: Nano Swat Teams Kill Cancer

In March 2009, Geoffrey vonMaltzahn, a graduate student and biomedical engineer in the Harvard-MIT Division of Health Sciences and Technology, won the $30,000 Lemelson-MIT Student Prize for two of his inventions in nanomedicine: a new class of cancer therapeutics and a new paradigm for enhancing drug delivery to tumors. Tracy Staedter chats with him about how his therapy works.

imtracynotstacy: Hello Geoffery.
3:10 PM

gvonmalt2007: Hi Tracy

imtracynotstacy: Good to talk to you again.

gvonmalt2007: Thanks for the chance to chat.

imtracynotstacy: We had a phone conversation back in December about your remote-controlled nanoparticles. I'm checking in now to see what you've been up to since.
3:12 PM

gvonmalt2007: I hope you're not expecting any Nobel's since December!
But I can give you an idea of our "progress", sure

imtracynotstacy: Sounds great.
First I want to talk about nano
Nano is tossed around a lot these days
I mean the size
people think of the iPod, sure
but can you talk about nano-sized stuff and how you work with those teeny tiny particles?

gvonmalt2007: Sure, well, as a community and a science, you're right, nanotechnology is growing at an incredible pace.
Sorry if this is slow -- I have 100 programs open on my computer and it's struggling!
But there are a lot of good reasons for the interest -- nanoparticles can do some really cool stuff!

imtracynotstacy: even if they're small?
3:14 PM

gvonmalt2007: You bet -- They have new physics that bridges the physics that we see in stuff our size with atomic physics.
So they can be much brighter than molecules, or they can exhibit superior magnetic properties, or, simply because they are on the same size scale as proteins/lipids/DNA in our bodies, they can "talk" to those biological things in new ways, compared to much larger things

imtracynotstacy: so when you're talking about nanoparticles, you're talking about things about the size of molecules? give or take?
3:17 PM

gvonmalt2007: let's call a molecule ~1-5nm (although polymers can be much larger) and a cell in our body is ~15000 nm
and we're working with things that are much smaller than a cell
and slightly larger than small molecules
our particles are between about 20nm and 150nm, so span between the size of some very large proteins and the size of most viruses

imtracynotstacy: got it. and so you are engineering these particles to do what basic thing? kill some disease?
3:21 PM

gvonmalt2007: Our focus right now is treating and imaging cancer and what I'm working on is making "teams" of multiple nanoparticles that can work together to do that more efficiently

imtracynotstacy: hmmm. teams? what do you mean by that?
3:22 PM

gvonmalt2007: Basically, we're trying to target cancer more quickly and with more specificity. And finding cancer in a patient is an extraordinarily difficult task.
So, it would be kind of like if I took a group of people here in Boston and asked them to find a cake shop that sold purple cupcakes
But they had no cell phones
and so they can't communicate with one another. And although they all know what to look for, it would take them a really really long time before every single one of them found it
But then again, if they did have cell phones, once one of them found it (which may still take a little while), the rest of them would zero in on it in no time
3:25 PM

gvonmalt2007: I'm trying to make nanoparticles that can "communicate" kind of like that-- where once one finds the tumor, they try to make it easier for the others

imtracynotstacy: ok. great analogy
so what's the cell phone? How are you equipping these guys with communication?
3:27 PM

gvonmalt2007: Yea, unfortunately cell phones haven't made it quite that far yet
So we have to think about other ways of communicating
And a great place to look is biology
A wonderful example of a system of "nano"-sized things working together to efficiently target is blood clotting

imtracynotstacy: like when you get a cut?

gvonmalt2007: For most of us, when we fall down, get a cut, a scrape, there is this incredible response that allows proteins and cells in your blood to rapidly sense that and target it, to essentially form a new tissue
If only we could target cancer that well!
But there's a catch to this analogy
and it's that blood clotting is extremely complicated
it involves hundreds of coupled biochemical reactions with small molecules, proteins, cells, etc. and we don't really understand it all that well
Which makes it hard to build something that you don't understand
So, instead of being able to build that whole thing from scratch, we've taken relatively simple lessons from those sorts of examples and are trying to replicate them with nanoparticles

imtracynotstacy: I see
but how did you think to use blood clotting as a model for this cancer targeting scheme? Or is clotting just an example you gave me?
3:34 PM