Using Dextran-encapsulated gold nanoparticles as insulin carriers to prolong insulin activity

Abstract

Aim: Diabetes mellitus is commonly treated with painful insulin injections. We aim to explore drug carriers that can prolong insulin activity. Materials & methods: Dextran-encapsulated gold NPs (AuNPs@Dextran) that can bind with insulin are used as insulin carriers. The affinity (Kd = similar to 42pM) between insulin and insulin receptors on the cells is much higher than that (Kd = similar to 4.02 mu M) of insulin and AuNPs@ Dextran. Thus, insulin released from the AuNP@Dextran- insulin conjugates to maintain kinetic equilibrium and prefers to bind to the insulin receptor. The slow release of insulin from the AuNP@ Dextran-insulin conjugates facilitates the lasting of insulin activity. Results & discussion: AuNP@ Dextran-insulin conjugates can prolong insulin activity to 12 h, whereas free form insulin loses activity after 4 h in adipocyte cells. Conclusion: AuNPs@ Dextran are suitable carriers that can prolong insulin activity.