Nano-everything has been the rule for several years now, to judge from press releases and poster abstracts. But here's an article in Nature Reviews Drug Discovery that's wondering what, exactly, "nanomedicine" has offered so far:
. . .Indeed, by some quantitative measures, the field is flourishing; over the past decade there has been an explosive growth in associated publications, patents, clinical trials and industry activity. For example, a search of the worldwide patent literature using 'nanoparticle and drug' resulted in over 30,000 hits. . .
New biomedical technologies have often undergone a similar life cycle. Initially, exciting pioneering studies result in a huge surge of enthusiasm in academia and in the commercial arena. Then, some of the problems and limitations inherent in the technology emerge, the initial enthusiasm is deflated, and many players leave the field. A few enthusiasts persist and eventually the technology finds its appropriate place in research as well as in clinical and commercial applications. It seems possible that nanomedicine is now verging on the phase of disillusionment.
That's exactly the cycle, and what's never clear is how steep the peaks and valleys are. Some of those deflationary cycles go so deep as to take out the entire field (which may or may not be rediscovered years later). That's not going to happen with nanoparticle drug delivery, but it's certainly not going to make everyone rich overnight. As the article goes on to detail, these formulations are expensive to make (and have tricky quality control issues), and they're not magic bullets for drug delivery across membranes, either. So far, the record of the ones that have made it to market is mixed:
. . .Addressing these challenges would be strongly justified if major benefits were to accrue to patients. But is this happening? Although we do not know the potential benefits of the nanomedicines currently under development, we can examine the early-generation nanoparticle drugs that entered the clinic in the 1990s and 2000s, such as the liposomal agents Doxil and Ambisome and the protein–drug nanocomplex Abraxane. These agents are far more costly than their parent drugs (doxorubicin, amphotericin B and paclitaxel, respectively). Furthermore, these nanomedicines made their mark in the clinic primarily by reducing toxicity rather than improving efficacy. . .
The big question is whether these toxicity reductions warrant the increased prices, and the answer isn't always obvious. The current generation of nanoformulations are different beasts, in many cases, and it's too early to say how they'll work out in the real world. But if you Google the words "drug nanoparticles revolution", you get page after page of stuff, and clearly not all of it is going to perform as hoped. Funding seems to be cresting (or have crested) for this sort of thing for now, and I think that the whole field will have to prove itself some more before it climbs back up again.