Glucose-responsive materials are of importance for the development of insulin regulatory systems that can be used in hyperglycemic therapies for diabetics. Prasanta Kumar Das and colleagues, Indian Association for the Cultivation of Science, Kolkata, India, have been looking into the use of low-molecular-weight gels (LMWGs) for such an application.

Their approach allows the fluorimetric sensing of minute amounts of glucose at physiological pH. The team uses a combination of diol-sensitive phenylboronic acid (PBA), a known saccharide receptor, and pyrene in a hydrogelator. The addition of glucose induces swelling in the hydrogel, which in turn causes insulin to be released from the gel.

The insulin-loaded hydrogel showed thixotropic properties (becoming fluid when stirred or shaken), which meant that is can be used as an injectable soft composite. First cell viability tests of the gelator with HeLa cells showed that the gel was compatible.

• Phenylboronic Acid Appended Pyrene-Based Low-Molecular-Weight Injectable Hydrogel: Glucose-Stimulated Insulin Release,
  Deep Mandal, Subhra Kanti Mandal, Moumita Ghosh, Prasanta Kumar Das,
  Chem. Eur. J. 2015.
  DOI: 10.1002/chem.201501170