Core–Shell Microneedle Gel for Self-Regulated Insulin Delivery

Abstract

A bioinspired glucose-responsive insulin delivery system for self-regulation of blood glucose levels is desirable for improving health and quality of life outcomes for patients with type 1 and advanced type 2 diabetes. Here we describe a painless core–shell microneedle array patch consisting of degradable cross-linked gel for smart insulin delivery with rapid responsiveness and excellent biocompatibility. This gel-based device can partially dissociate and subsequently release insulin when triggered by hydrogen peroxide (H2O2) generated during the oxidation of glucose by a glucose-specific enzyme covalently attached inside the gel. Importantly, the H2O2-responsive microneedles are coated with a thin-layer embedding H2O2-scavenging enzyme, thus mimicking the complementary function of enzymes in peroxisomes to protect normal tissues from injury caused by oxidative stress. Utilizing a chemically induced type 1 diabetic mouse model, we demonstrated that this smart insulin patch with a bioresponsive core and protective shell could effectively regulate the blood glucose levels within a normal range with improved biocompatibility.

Hollow Polypyrrole Nanospindles for Highly Effective Cancer Therapy

“…[1] In particular, hollow structures with excellent biocompatibility have become good candidates for drug delivery carriers, due to their controlled release of drugs, large void space, and tunable pore sizes. [2][3][4][5][6] Over the past years, a large number of hollow structures have been developed as drug delivery carriers including Au hollow nanocages, [7] carbon hollow nanoparticles, [8] hollow silica nanoparticles, [9] hollow polymer nanospheres, [10] and so on. Besides, the therapeutic effect of photothermal therapy (PTT) can be improved by constructing hollow structures because of the increase of light absorption via large surface areas.…”

DNA Extraction from Plant Leaves Using a Microneedle Patch

“…The fabrication process is very simple and inexpensive and it does not involve any special facilities such as cleanrooms. Each MN patch consists of 225 conical MNs and these strong MNs easily penetrate human skin and plant tissues without breaking (Wang et al, 2018;Wang, Ye, Hochu, Sadeghifar, & Gu, 2016;Yu et al, 2015).…”

Advanced hydrogels for treatment of diabetes

“…At physiological pH, the patch displays a fast glucose‐dependent insulin release, which extends for up to 20 hr. In addition, this patch restored euglycaemia once placed on top of the dermis of diabetic mice (J. Wang et al, ).…”

“…In addition, this patch restored euglycaemia once placed on top of the dermis of diabetic mice (J. Wang et al, 2018).…”