Dr. David Kaplan on Silk and Temp Controlled Vaccine Supply Chain

Dr. David Kaplan, Stern Family Professor of Engineering, Professor and Chair, Department of Biomedical Engineering at Tufts University, speaks to Cold Chain IQ, about stabilisation of vaccines and antibiotics in silk and eliminating the cold chain.

Cold Chain IQ: You have published some really interesting research lately. Could you just give our members a brief overview?

D Kaplan: The basic concept that we’ve been working on is to develop biomaterial matrices or protein matrices, if you will, that can entrap and stabilise various therapeutics that are otherwise very unstable at room temperatures or higher temperatures. So, the goal is to develop systems that will allow the use of these therapeutics without the need for refrigeration.

Cold Chain IQ: And how do you think healthcare delivery could benefit directly from this research?

D Kaplan: I think in a number of ways this could be very useful. As your audience, I’m sure, knows, many key therapeutics, whether they’re vaccines, antibiotics, enzymes etc. tend to be very unstable unless they’re kept at refrigeration or even colder temperatures that lose bioactivity fairly rapidly and so what we’ve been working on is ways to entrap/stabilise such otherwise labile compounds so that you can avoid this kind of refrigeration.

And if you can do that successfully, then you open up windows of opportunity where you can, number one, distribute therapeutics worldwide without the so-called cold chain and not run the risk of loss of bioactivity. You can think about new ways for personalised medicine where therapeutics can be carried in your pocket, if you will, and used on demand when needed and then you can also think about new ways to functionalise medical devices with therapeutics that would otherwise be difficult to do as long as they’re stabilised, for example, as proteins. Cold Chain IQ: What potential impact do you think this research will have on the biopharmaceutical community?

D Kaplan: We hope a big impact but that remains to be seen over time. Our goal is to obviously work with industry to transition our research into their hands as things move forward and hopefully have them find the best matches for this technology to enhance what they’re able to generate for the medical community. So, we look forward to seeing those next steps.

Cold Chain IQ: And what was the reasoning behind selecting a silk protein for further investigation?

D Kaplan: Actually our lab has studied these proteins, these silk proteins, for over 20 years, I think, so it’s been a long time of very basic study the first ten, 12 years where we were just trying to understand this very unique protein material and how it’s able to form such incredibly robust materials in many formats and that led us to further study the biological interactions, the genetics, the biochemistry etc. and, as we continue to understand the mechanisms of how this protein self-assembles the material properties, it became clear that it had broader potential in the medical device arena than just sutures which has historically been basically the only use for silk and that led us down a path of exploring many different biomedical applications from tissue engineering to just basic biomaterials and that’s continued to grow in recent years.

Cold Chain IQ: And what procedures did you follow for stability testing?

D Kaplan: Generally in the simplest terms we take the silk protein that we sort of deconvolute into a solution, aqueous solution, state, so you just have water and silk protein. We then add whatever therapeutic we’re going to study into that solution and then rapidly form a self-standing stable material. It could be a film, could be a fibre, could be a gel, really any material format. And once we have that material, then we take those materials and we entrap the therapeutic and we place it in different storage stability environments. So, in the case of the recent paper with vaccines and antibiotics, we put these at different temperatures over time and in these studies they went out to about six months. And then we periodically sampled the materials, recover the therapeutic and assess bioactivity to determine how well we’re doing. Cold Chain IQ: There’s certainly a degree of buzz about this at the moment in the community, but how soon do you think it will be before we see this tested in the field?

D Kaplan: We hope as soon as possible because we feel the technology clearly has potential based on the data we’ve presented in the paper but, again, it’s going to depend on our partnerships with industry and how quickly we can kind of mobilise with them to get the samples to sort of the next level of field study. So, we’re hopeful quite soon for some of them. Obviously for others that are in direct contact with humans it’s going to take regulatory approval and that’ll take a little longer.

Cold Chain IQ: And what are your next steps in this investigation? D Kaplan: The goal is, number one, as mentioned already, to develop appropriate partnerships with industry to move the technology into their hands and those discussions are underway, and the other is to continue the research side to demonstrate the breadth of utility of the technology with different therapeutics and we’re making good progress there. And the second area of fundamental work is to continue to fully understand the mechanisms that allow this pretty remarkable stabilisation to occur so that we can, again, continue to improve what we’ve learnt already.

Cold Chain IQ: What other research are you personally very interested in and what do you think could potentially be a game-changer for the way the pharmaceutical landscape is as a whole?

D Kaplan: Being a little self-centred about it from our own studies, we published also this past year on developing silk-based micro needle and micro needle technology’s been around for a while now with some good successes but some of the limitations for the technology we’ve demonstrated with silk you can essentially overcome them.

So, you can imagine or envision, or at least we can, developing small micro needle band aids of pure silk with pre-incorporated therapeutics. So, if they’re already stabilised you could essentially distribute these anywhere in the world with retention of bioactivity for months, if not years, and when you’re ready to use this, whether it’s because you’re out camping or you get exposed to something, you just open up the package, the band aid strip, you put it on your skin and the bioactive molecule is delivered through the silk matrices that poke through the outside layer of your skin. When you’re done, it’s pure protein that’s left. You peel it off and you can recycle it or do what you want, degrade it and on you go.

So, we would love to see this integrated stream of, you know, pharmaceutical manufacturing/processing/device application all in one process going forward which would make things at least streamlined in many respects.

Cold Chain IQ: Do you think this is the end of the cold chain as we know it?

D Kaplan: I don’t think so. I think this new technology hopefully will have a lot of applications and utility. My guess is there’ll still be certain needs for a cold chain and I don’t think we’re ready to unplug all our freezers and refrigerators but I do hope there’s a major impact here and we’re very optimistic about it.

Interview conducted by Andrea Charles.

Have a question about this research? Rich Ellinger, Principal, Temperature Assurance Group, puts your questions Dr. David Kaplan http://www.coldchainiq.com/supply-chain-security/columns/nih-funded-silk-study-questions/