Three Dimensional Printing for Personalized Medicines

The advent of the industrial revolution brought with it innumerable horrors, alongside great advances; the very thought that humans could be transported in vehicles mobilizing at speeds greater than a horse’s canter was simply terrifying. People would surely die in transit, after all: if not of shock, then in the collisions that would ensue, when these inherently unstable and unsafe vehicles span out of control. Yet fast forward approximately two hundred years, and we now have mass-manufactured road-worthy motors for all.

The reason I mention this was that I was recently asked in an interview, for a junior doctor job, what I thought one of the “great ideas” of the 21st century was, albeit specific to healthcare. Not a question I had prepared for, admittedly, and which caught me off-guard; the first and only thing that sprang to mind, after the serendipitous discovery of penicillin (too cliché), was the advent of 3-dimensional printing, or 3DP. My interviewer—a rusty chap of about 80, wearing what looked to be an old boys’ rugby tie, offset by a pinstriped white and pink blazer—looked perplexed. “And why is that?” he asked. Well, I argued, innumerable reasons really. 3DP is a revolution in itself; a self-descriptive method of printing bespoke objects in three dimensions. In simple terms, you plug into a computer what shape and size of the object that it is you want (a yo-yo, for instance); the computer feeds this information to the printer, and the printer proceeds, as per instructions, using whatever material you have supplied it with (usually heated—and therefore malleable—plastic). The limit is your imagination (and, admittedly, the resolution of the printer). 3DP has its finger in every pie, from construction to computing, healthcare, and even reproducing human organs, for surgical transplantation, using organic tissues as the printing material. I got the job, at any rate; whether my spiel on 3DP was responsible remains another matter.

So where does 3DP fit into in the grand scheme of human pioneering? Well, perhaps where the first gap wasn’t filled in the first place: indeed, a notable limiting factor to mass production of motorized vehicles is customization. By definition of their being generically rolled out, there leaves little room for individuality. That would be expensive; it would require different machinery, parts, and production techniques. Not efficient. Such premise harks back to John Henry Ford, the founder of Ford Motors, who was illustriously quoted with his take on Hobson’s choice: “you can have any colour, as long as it’s black.”

Yet mass production does have its drawbacks, and not least in medicines. All drugs that are generically mass-made are of fixed, standardized doses, in line with regulatory requirements. They have to satisfy standards of safety and efficacy, within a margin of dosing error ranges. Yet where one dose could be effective in one person, it could have no effect (or, worse, a toxic effect) in another, purely down to the way in which an individual processes that drug per se.

One area in which 3DP has fallen behind, ironically, is in medicines, yet has a great deal of potential. Oral medicines—tablets, capsules, liquids— remain the most commonly preferred, and marketed drug formulations worldwide, but are limited by the notion that only around 50 percent of each dose is effective in those people taking them. Whilst my disclaimer here is that no one on regular prescribed medicine should suddenly stop taking their medicines based on the approximation that there is a one in two chance that it’s actually doing them any good; in fact, the reasoning for this is much more complicated. No one person is the same, and hence arguably no one dose should be the same. This is where the premise of personalized medicine comes into play.

So, what is a “personalized” medicine? I tend to use the analogy of Cinderella’s slipper in this case: one size does not fit all, and certainly one dose does not fit all. Take any patient group with the same diagnosis, given the same prescription, and only a small proportion of them will respond in a meaningful way, without experiencing any significant side-effects. Indeed, medics are keen to treat patients homogeneously; we write guidelines for management of specific conditions, even though there may be glaring differences in an individual’s presentation of a disease. By specifically tailoring a dose and a dosage form to best suit a person’s metabolism, physiology, and preference, however, we can minimize side-effects, improve the overall benefit of the drug, and help ensure that the patient does actually want to take the medication that they have been prescribed and will do so regularly.

Medicines can also arguably be made more appealing via 3DP—current researchers in medicine and pharmacy argue that the end-goal would be that patients are able to print their own prescriptions at home, on demand, and tailored specifically to them (shape, size, colour —you name it). A research group that I have worked with has even taken steps to improve medicines—taking in children by 3D printing dinosaur-shaped formulations, suitable for human consumption.

3DP is a rapidly-evolving field, and exciting developments are an almost daily occurrence: the advent of newer printer models, combined with clinical imaging software as well as inkjet printers, that can directly print drugs onto different materials, have been crucial drivers in the field of drugs and devices, and news that Microsoft have just acquired the rights to scan everyday objects for 3DP purposes is a ground-breaking prospect. What remains to be seen is whether 3DP can ultimately inform how to fabricate the most optimal oral medications with which to safely and effectively dose patients on a mass-scale; albeit not something it was intended for initially, but which certainly shows—as with the steam engine—incredible promise.

References:

http://www.dailymail.co.uk/health/article-3125396/Don-t-like-pills-Just-turn-dinosaur-sweets.html