Safety evaluation of 3-month effects of microneedle patches prepared from hyaluronic acid in mice

Abstract Dissolving microneedles (MNs) is a promising alternative way to traditional subcutaneous injection delivery of insulin. At present, there are numerous soluble materials have been used to fabricate dissolving MNs for insulin delivery. However, during insulin delivery of dissolving MNs, the effect of the MNs to the skin and the safety of the matrix material remained in the skin should be seriously considered, especially for the diabetes who need frequent and long-term self-administration of insulin. In this work, we investigated the long-term effects of hyaluronic acid (HA) MNs on mice after daily insertion in a period of 3 months. The general conditions, hematology and blood biochemistry of mice were examined at different time. The main organs of the mice administrated by the HA MNs were dissected at 90 days, and the organ coefficients and histological evaluation were measured and recorded. The results showed that there was no erythema and inflammation happened on the skin at the HA MNs insertion sites and no significant histopathological abnormalities were observed in the treated mice compared with the control mice in 90 days.