Washington: Say goodbye to good old needles, as a team of scientists has come up with an alternative for the diabetics in the form of seaweed capsules.
Pancreatic islet transplantation is an effective treatment for type 1 diabetes that can dramatically reduce daily doses or even eliminate dependence on external insulin. Cryopreservation, or deep freezing, is the method commonly used for the islet preservation and transportation. But it is not completely safe.
A group of scientists from the Okinawa Institute of Technology and Science Graduate University (OIST) in collaboration with the University of Washington and Wuhan University of Technology led by Prof. Amy Shen developed a novel cryopreservation method that not only helps to protect pancreatic islets from ice damage, but also facilitates real-time assessments of cell viability. Moreover, this method may reduce transplant rejection and, in turn, decrease use of immunosuppressant drugs, which can be harmful to patient health.
The novel technique employs a droplet microfluidic device to encapsulate pancreatic islets in hydrogel made of alginate, a natural polymer extracted from seaweed. These capsules have a unique microstructure: a porous network and considerable amount of non-freezable water.
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 minimise or prevent freezing damage and can be toxic in high concentrations.
Another innovation, proposed by the group, is the use of a fluorescent oxygen-sensitive dye in hydrogel capsules. The porous structure of the capsules does not impede oxygen flow to the cells. And this dye functions as a real-time single-islet oxygen sensor. Fluorescence indicates whether cells are consuming oxygen and, therefore, are alive and healthy. It is a simple, time-efficient, and cheap method of assessing viability, both of individual islets or populations thereof.
The microencapsulation method can help to overcome some major challenges in pancreatic islet transplantation, including the scarcity of available islets and the lack of simple and reliable control methods, especially for individual islet assessment. It offers hope to patients suffering from type 1 diabetes to return to a ‘normal’ life, free of insulin injections.
The study appears in Advanced Healthcare Materials.