Lyophilized insulin micelles for long-term storage and regulation of blood glucose for preventing hypoglycemia

• Insulin micelles ( P 1 M 10 @INS ) possess a high loading efficiency (91.5%) and loading content (18.6%). • Long-term glucose modulation by P 1 M 10 @INS is superior to the commercial insulin glargine. • P 1 M 10 @INS is stable at room temperature and can be lyophilized for solid formulation. • Protein therapeutics without cold-chain requirements is a breakthrough in developing countries. The administration of exogenous insulin is an important treatment for improving diabetic patients’ health but involves multiple daily subcutaneous injections. The development of insulin formulations for long-acting effects has been hampered by short pharmacokinetics and reduced bioactivity due to long-term storage. To solve this, we developed a formulation with a high insulin loading efficiency achieved via the self-assembly of an amphiphilic polymer (P 1 M 10 ) and insulin. In a type 1 diabetic rat model, P 1 M 10 @insulin micelles quickly and continuously controlled the blood glucose level without risk of hypoglycemia, showing a better therapeutic index than the commercial long-acting insulin glargine. In addition, the P 1 M 10 polymer could protect insulin in solution at room temperature in the long term. Owing to this protection, P 1 M 10 @insulin micelles could be lyophilized and reconstituted without any loss of insulin bioactivity, allowing for convenient transportation and storage of therapeutic proteins under normal conditions, which would greatly expand their application scenarios.