Microneedle Patch Prepared from a Hydrogel by a Mild Method for Insulin Delivery

Abstract

Most reported microneedle patches still suffer from a complicated preparation process and insufficient loading capacity for the glucose‐responsive delivery system. Herein, based on the reversibility of the boronate ester bond, a novel gel was formed by mixing phenylboronic acid grafted sodium hyaluronate and polyvinyl alcohol. The insulin‐loaded microneedle patch could be directly obtained by simply blending high‐dose insulin and gel into the mold. The introduction of cellulose nanofiber was also found to be in favor of mechanical strength. The glucose responsibility could be achieved when the boronate ester bond was broken by glucose, leading to the change of crosslinking density and further controlling insulin release. In the hypoglycemic experiment of diabetic rats, the microneedle patches could effectively puncture the skin and maintain normal blood glucose levels for an extended period. The facile preparation process and high loading capacity give this microneedle patch a great chance in mass production.

Glucose‐Responsive Microneedle Patch With Variable Crosslinking Density and Flexible Core–Shell Structure for Insulin Delivery

“…ATR-FTIR, XRD, and DSC Characterization of the GRF: The experimental methods were according to our previous research with some changes. [17,21] The structure was analyzed by ATR-FTIR, and the scan rate was set to 20 min −1 and the resolution was 4 cm −1 . XRD was used to analyze the crystallinity of the GRFs.…”

“…Mechanical Strength of the GCSMP: The experimental methods were according to our previous research with some changes. [17,21] The prepared microneedle patch was trimmed into a 13 × 13 array with a total of 169 needles. The mechanical strength of the microneedle patch was measured by a compression test on a universal material testing machine (Zwick/Roell Z020, Zwick Co. Ltd, Germany).…”

“…In Vivo Studies of the GCSMP for Type 1 Diabetes Treatment: The experimental methods were according to our previous research with some changes. [17,21] The animal study was approved by the Research Ethics Committee of the First Affiliated Hospital, College of Medicine, Zhejiang University (Approval number: 20191106). The diabetic rat model was induced using streptozotocin (STZ) according to the literature.…”

“…MTT Analysis of the Material: The experimental methods were according to our previous research with some changes. [17,21] The cytotoxicity of the material was studied using a colorimetric methyl thiazolyl tetrazolium (MTT) assay on L929 cells. The PVA/PLL-FPBA GRF sample (0.11 g) was soaked in a cell culture medium (11 mL) at 37 °C for 24 h and gradually diluted to prepare serial dilutions.…”

Recent Advances in Polymer Microneedles for Drug Transdermal Delivery: Design Strategies and Applications

“…This method does not cause pain and brings light to the minimally invasive treatment of diabetes. [ 180,181 ] Currently, based on the different glucose‐responsive moieties, various closed‐loop insulin delivery systems have been proposed to effectively regulate the blood glucose level of diabetic patients, which include glucose oxidase (GOx) and phenylboronic acid (PBA)…”