Tufts Silk Portfolio

Biomedical engineers David Kaplan and Fiorenzo Omenetto took a material that’s been around for thousands of years — silk — and created hundreds of distinct, high-technology products and applications that could transform healthcare.

David Kaplan, chair of biomedical engineering at Tufts University, has worked on medical applications of silk for over twenty years.  In 2006 he began collaborating with Fiorenzo Omenetto, a specialist in optics, in creating silk-based nanoelectronics.

Discoveries proliferating from the Kaplan and Omenetto labs have launched four start-up companies and brought millions of dollars in industry sponsored research funding to the university.  Tufts silk innovations have been featured on the front page of the New York Times Science Section, at TED 2011, on NPR, and in The Economist. The possibilities for new applications seem limitless.

Fiber that punches above its weight

Silk fibers are outstanding material systems with a toughness that is superior to any synthetic high-performance fiber now available, including Kevlar.  The high strength and extensibility of natural silk result from the way the proteins are organized. They are folded in complex ways that give silk its unique combination of attributes and enable performance that is unobtainable from other materials.

Kaplan and Omenetto transform regenerated silk solutions into biomaterials such as hydrogels, fibers, sponges, and films — modifying their mechanical properties according to the way the silk is processed.  One advantage with silk biomaterials is that their mode of manufacture is “green”: The process is water based and takes place at ambient temperatures, advantages that allow easy incorporation of drugs or other compounds into the silk.

The amazing applications for silk span the consumer-goods, pharmaceutical, medical, high-tech-optical, and electronics markets. This game-changing material could be used in applications ranging from biological stabilization to refrigeration-less vaccine storage and vascular tissue engineering to cosmetic/reconstructive surgery. Not surprisingly, there has been a flood of commercial interest in the silk portfolio.

Silk spin-outs

Martin Son is an associate director at Tufts Tech Transfer and has been instrumental in negotiating licensing agreements that establish silk-based start-up companies. Son has coached David Kaplan and Fiorenzo Omenetto during the various phases of protecting and commercializing the silk portfolio. Son’s goals are to ensure that silk innovations are transformed for public use and benefit and made widely available. “It’s very rewarding to be able to interact with world-class faculty members who are working on ideas that could transform patient care” he says. “My underlying goal is to help Tufts innovators fulfill their intellectual and commercial potential.”

Start-up ventures based on silk innovations have the potential to revolutionize healthcare. Serica Technologies was formed in 1998 to develop tissue engineering products based on native silk fibers from silkworms. The company received FDA approval for its first product, a long-term bioresorbable surgical mesh designed for the support and repair of weakened or damaged connective tissue. Allergan recognized the possibilities of the native fiber–based silk platform and acquired Serica in 2010. Allergan continues to develop Serica’s biodegradable silk-based scaffolds from a state-of-the-art office, R&D, and manufacturing facility in Medford, Massachusetts.

In October 2009 Tufts entered into an exclusive license agreement and multi-year sponsored research collaboration with Ekteino Laboratories. Ekteino is developing a sustained-release drug delivery system for medications that are taken chronically. The aim is to extend the interval of time between drug doses, thus improving patient compliance and clinical outcome. Advantages of sustained-release technology based on silk polymers include excellent biocompatibility, controlled biodegradation, degradation by-products that are aqueous and do not provoke inflammation, and processing at ambient temperatures. Expected benefits, when compared with conventional sustained-release systems, such as PLGA [co-polymer poly(lactic-co-glycolic acid)], include a minimal inflammatory response, all-aqueous processing to avoid loss of bioactivity to peptide and protein drugs,  and a longer-term retention of drug activity.

The most recent silk start-up, Vaxess Technologies, is exploring silk-based solutions for vaccine thermostabilization and storage. The company aims to create vaccines that can be stored and shipped around the world without refrigeration. Upon delivery to the health care provider, the silk-stabilized vaccine would be reconstituted and administered to the patient in the traditional manner.

Platform for the future

What are the future possibilities for this revolutionary biomaterial platform? When you start to bring together therapeutic, optical, and protein elements, the prospective innovations are boundless.

David Kaplan and Fiorenzo Omenetto’s recent innovations include edible optical sensors that could make food safer, high-strength scaffolds to improve bone repair, and biocompatible electronic devices that could dissolve harmlessly in the body or into their surroundings.

Martin Son intends to continue catalyzing productive relationships between Tufts and industry to commercialize promising silk innovations. “The silk portfolio has tremendous potential and I look forward to future ventures that make products derived from this disruptive platform available for public benefit.”