Futuristic tissue engineering

New smart microfibres target emerging drug therapies for deadly disease

When University of Victoria biomedical engineer Mohsen Akbari gets talking about the futuristic microfibres being created in his lab to solve medical mysteries, it sounds just about as far away from nature as you can get.

But in fact, nature is both inspiration and blueprint for the work of the Laboratory for Innovation in Microengineering (LiME). Researchers at the multi-discipline lab study what nature already does brilliantly, then work to recreate that in the lab to improve how to treat disease and administer drugs.

Akbari’s team studied how spiders secrete multiple proteins that together create a marvelous web-spinning fibre. From that came “smart microfibres” for weaving into gauze-like fabric to treat burns and other wounds using “smart bandages.” The fibres are engineered to detect the earliest sign of infection and deliver drug therapies without a bandage ever having to be removed—a process that can be monitored by a smartphone signal.

LiME scientists study the characteristics and interactions of body systems, and then reverse-engineer them in the lab. They’ve now created microfibres that mimic skeletal muscle, the spinal cord and peripheral nerves so emerging drug therapies can be tested with much more accurate results.

Microfibres can also be woven into “smart mesh” engineered to manage drug delivery to a diseased organ. The work LiME is doing on glioblastoma is an example.

Only one drug treats the aggressive brain cancer, but it’s so toxic to other organs that just five per cent of patients treated are helped. Akbari says that using this mesh, surgeons could remove a tumour, print the mesh on the spot using a 3D printer, and line the tumour cavity with it. The drug would then be placed inside the mesh directly in the brain and slowly released, avoiding harm to other organs and allowing for higher doses.

“If we could even see 10 per cent of people helped by this, it would be a huge improvement,” says Akbari.

Improving drug therapies is a major focus of Akbari’s work. But developing new drug therapies is still a hit-and-miss process with a huge failure rate, says Akbari. Among the various reasons for that are two practices in drug-testing that nobody has been able to get around so far: culturing new compounds in Petri dishes; and testing them on lab animals such as mice.

Neither are good stand-ins for the detailed systems and highly specific DNA of the human body, says Akbari. “The body is pretty complex.”

But through the work of LiME, emerging drugs can be tested on microfibres that mimic human tissue. Drug developers can hone in sooner on effective therapies, and see how they work on fibres specifically engineered to replicate the part of the body to be treated. Smart microcapsules built from new materials will soon carry drug payloads directly to a diseased organ, avoiding toxic side-effects on other body systems.

Might a day be coming when whole new organs will be woven from these microfibres and materials? That’s still a dream, says Akbari.

“Nobody has figured out how to vascularize organs, to replicate all those blood vessels,” he says. “Nature still wins. That’s why we look to nature for answers.”

Edgewise

Only 10 per cent of new drug therapies make it to market, and less than a third of those that do are as effective as hoped. Much of that is due to how the body distributes drugs, and challenges in administering drugs so that treatment is concentrated in the diseased parts of the body without affecting healthy organs. The loss of hair among people undergoing chemotherapy is an example of drugs causing unintended side effects.

Microfibres being engineered in LiME take their inspiration from nature and are put together using classic textile techniques, including braiding, weaving and embroidery.

A single “smart bandage” can be woven from a variety of microfibres with different properties, including some that can deliver drugs and others that conduct elec tricity to create heat for triggering the release of drugs. Other microfibres are engineered to mimic bone marrow, muscle, or the grooved interior of the spinal column, creating a more realistic “human” platform for testing new drug therapies.

Much of LiME’s innovative bioengineering research is being led by Akbari’s graduate students, including Bahram Mirani in multi-functional microfibres and 3D-printed mesh; Hossein Dibiri and Lucas Karperien in smart microfibres; and Brent Godau in tissue printing.

Akbari’s research is funded by government and the private sector, including the Natural Sciences and Engineering Research Council of Canada, Canadian Institutes of Health Research, Rheolution Inc., 4M BioTech, RepliCel, and the BC Cancer Foundation.