Injectable sponge delivers controlled release of drugs

The sponge is said to expand and contract in response to blood sugar levels to release insulin as needed. The technique could also be used for targeted drug delivery to cancer cells.

‘We wanted to mimic the function of health beta-cells, which produce insulin and control its release in a healthy body,’ said Dr Zhen Gu, lead author of a paper describing the work and an assistant professor in the joint biomedical engineering program at North Carolina State University and the University of North Carolina at Chapel Hill. ‘But what we’ve found also holds promise for smart drug delivery targeting cancer or other diseases.’

The research team includes Daniel Anderson, the senior author and an associate professor of chemical engineering and member of the Koch Institute for Integrative Cancer Research at MIT, and researchers from the Department of Anaesthesiology at Boston Children’s Hospital.

The researchers created a spherical, sponge-like matrix out of chitosan, a material found in shrimp and crab shells. Scattered throughout this matrix are smaller nanocapsules made of a porous polymer that contain glucose oxidase or catalase enzymes. The sponge-like matrix surrounds a reservoir that contains insulin. The entire matrix sphere is approximately 250 micrometers in diameter and can be injected into a patient.