Glucose Responsive Rheological Change and Drug Release from a Novel Worm-like Micelle Gel Formed in Cetyltrimethylammonium Bromide/Phenylboronic Acid/Water System.

A novel glucose (Glc)-responsive gel formed by worm-like micelles (WLMs) has the potential to provide a self-regulating insulin delivery system. We have prepared a WLM gel system using 75 mM cetyltrimethylammonium bromide, 75 mM phenylboronic acid, and water. At pH 9.4, this gel-like system was highly viscous and supported its own weight, and dynamic viscoelasticity measurement indicated that it contained long and entangled WLMs. The visual observation of gels prepared to include >6 mM Glc revealed that these adopted a sol-like appearance, whereas those prepared to include a control compound (2-10 mM diethylene glycol) retained their gel-like appearance. The storage modulus ( G') of this system decreased as the Glc concentration increased (2-10 mM), indicating a gradual shortening of the WLMs. In vitro release was evaluated using a test compound (fluorescein isothiocyanate dextran) in a microsized flow system. By 120 min, the release of this compound from the WLM gel was around 27-fold greater in the presence of 100 mM Glc than without Glc or with 100 mM diethylene glycol. This demonstrated the successful preparation of a WLM gel that showed an altered drug release rate, depending on Glc concentration.

Rituximab provided long-term remission in a patient with refractory relapsing thrombotic thrombocytopenic purpura.

We describe a 69-year-old man with refractory relapsing thrombotic thrombocytopenic purpura (TTP) successfully treated with rituximab. The patient had once been successfully treated with plasmapheresis and vincristine, but he had relapsed after a short period. Although plasmapheresis, vincristine, and splenectomy could not achieve a consistent elevation of the platelet count, rituximab administration provided sustained remission for more than 7 months. Rituximab should be considered as a therapeutic alternative for refractory TTP.