Japanese scientists have developed a breakthrough hydrogel seaweed capsule that can help diabetes patients lead an injection-free life.
The research team, led by Professor Amy Shen from the Okinawa Institute of Technology and Science Graduate University, has invented a seaweed capsule capable of preserving pancreatic cells that can produce insulin.
Patients with type 1 diabetes need daily insulin injections. The transplantation of a pancreatic islet is an alternative method that can significantly lower daily doses of insulin and even abolish the dependence on external insulin. The procedure involves the transplant of islets taken from a donor pancreas to the diabetes patient.
To date, only human islets can be used in the transplant procedure, thus, the low supply. Cryopreservation or the deep freezing method is often used to preserve and transport the islet for the transplant. However, the usual cryopreservation technique is not absolutely safe since the cells may be exposed to ice damage.
Novel Cryopreservation: The Seaweed Capsule
The breakthrough seaweed capsule can preserve, protect and transport the pancreatic islets. It removes the possibility of ice damage and lowers the need for immunosuppressant medication, which could further harm the patient's health.
The new cryopreservation method makes use of a droplet microfluidic device to compress pancreatic islets in a hydrogel made from alginate, a seaweed extract polymer.
The capsule's microstructure has a porous network and non-freezable water that keeps the cells from ice damage.
"Hydrogel capsules with large amounts of non-freezable bound water protect the cells from the ice damage and reduce the need for cryoprotectants — special substances that minimize or prevent freezing damage and can be toxic in high concentrations," researchers said.
The encapsulation process also lowers the possibility of rejection by the recipient's cells. The novel cryopreservation method is non-invasive, unlike the current method that requires major surgery. Encapsulating the pancreatic islets in the seaweed capsules is also time- and cost-efficient.
The team also proposed the use of fluorescent oxygen-sensitive dye in the seaweed capsules, which have a porous structure that doesn't obstruct the oxygen flow in the cells. Acting as a real-time oxygen sensor for every single islet, the dye could monitor the cells' oxygen consumption, an indicator that they are healthy and alive.
The research was published in Advanced Healthcare Materials. The study was conducted in collaboration with the Wuhan University of Technology in China and the University of Washington in the United States.
