Abstract

Type 2 diabetes is driven by the gradual failure of the beta cells in the pancreas – the cells that produce insulin. These cells sit in small clusters called the islets of Langerhans, scattered throughout the pancreas and richly supplied with blood vessels. Gene therapy could, in principle, restore or protect them. The obstacle is delivery: a treatment given into the bloodstream is safe and simple to administer, yet almost none of it reaches the islets.

The prevailing explanation is that the delivery vehicles are somehow not drawn to the islets. My work suggests a different answer. By comparing tracers of different sizes and tracking where each one travels after entering the circulation, I found that the vessels feeding the islets behave like a fine sieve. Small molecules pass through easily, but anything approaching the size of a gene therapy particle stays trapped inside the vessel and never reaches the surrounding tissue. The problem is not attraction – it is access. I call this the Blood-Islet Barrier.

My research has three goals: to measure precisely how fine this sieve is, to engineer delivery vehicles that are actively carried across the barrier rather than relying on leakage, and to confirm those vehicles still work in the scarred, altered pancreatic tissue of established diabetes.

Together, these steps point toward a gene therapy that can be given by simple injection – one that reaches the failing beta cells directly, slows or reverses their loss, and restores the body’s own control of blood sugar.