Development of a Measure to Assess Attitudes Towards Nasal versus Autoinjector Glucagon Delivery Devices for Treatment of Severe Hypoglycemia.

Background: For individuals managing diabetes, the administration of glucagon for severe hypoglycemia can be lifesaving, yet, until recently, there were no easy-to-use devices for these stressful emergencies. New products have emerged to meet this need, including nasal glucagon (NG) and auto-injector glucagon (AI). This study evaluated the psychometric properties of a new measure, the Glucagon Device Attitudes Questionnaire (GDAQ), in assessing attitudes toward NG and AI from the perspectives of persons with diabetes on insulin (PWDs), caregivers, and acquaintances. Methods: Developed based on qualitative research, the GDAQ consists of 38 rating items for each device and 16 direct-elicitation of attitudes of device relative to each other. It was administered to participants via a cross-sectional online survey. Twenty-six rating items were included in principal component analysis and confirmatory factor analysis. Items comprising each factor were averaged to form scales. Additionally, 12 direct elicitation items were averaged to form an overall "Attitudes" scale. Reliability and validity analyses were conducted. Descriptive statistics were provided for the rating items not included in the factor analysis. Results: A total of 405 PWDs, 313 caregivers, and 305 acquaintances participated. Three factors were identified: "Prepared and Protected" (7 items), "Hesitation" (12 items), and "Device Perceptions by Others" (7 items); factor loadings ranged from 0.13 to 0.92, 0.50 to 0.89, and 0.16 to 0.92, respectively. Cronbach's alpha for the four scales ranged from 0.76 to 0.96. Correlations of the scales with their global item ranged from 0.30 to 0.90. The items outside of the factor analysis showed good distribution in responses and differentiation between the two devices. Discussion: This study supports the validity and reliability of the GDAQ, which successfully conceptualizes attitudes towards devices for administering glucagon among different respondent groups. Use of the GDAQ can help guide the development and testing of new glucagon drug/device combinations.

"Smart" Composite Microneedle Patch Stabilizes Glucagon and Prevents Nocturnal Hypoglycemia: Experimental Studies and Molecular Dynamics Simulation.

Hypoglycemia is a major complication associated with insulin therapy in people with diabetes that could cause life-threatening conditions if untreated. Glucagon, a counter-acting hormone, is thus administered for rescue of severe hypoglycemia. However, due to the instability of glucagon, only limited medications are available for emergency use, which are unsuitable for patients with hypoglycemia unawareness or with the inability to self-administer, especially during sleep (namely, nocturnal hypoglycemia). To prevent unattended and extended hypoglycemia, we designed a "smart" composite microneedle (cMN) patch capable of stabilizing glucagon, sensing hypoglycemia, and delivering glucagon automatically on demand. In this design, native glucagon was encapsulated in glucose-responsive microgels containing a glucagon-stabilizing component rationally selected by molecular dynamics (MD) simulation. A cMN patch was then prepared by incorporating the glucagon microgels with poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-MAH) and poly(ethylene glycol) (PEG) followed by thermal cross-linking. The rationally designed zwitterionic polymer-based microgels preserved the native structure of glucagon and prevented heat-induced fibrillation evidenced by RP-HPLC, circular dichroism, and transmission electron microscopy. MD simulations suggested that the polymeric microgels stabilized glucagon by inhibition of oligomer formation via peptide-polymer noncovalent interactions. The polymer formed multiple hydrogen bonds with the polar and charged amino acid residues of the glucagon molecule, shielding the peptide surface from aggregation. In vivo efficacy studies using streptozotocin-induced type 1 diabetic (T1D) rats demonstrated that the glucagon-loaded cMN patch could prevent hypoglycemia induced by insulin overdose during a 12 h period. The results suggest that this new glucagon "smart" patch may be a promising system for improving the quality of life of those suffering from nocturnal hypoglycemia and hypoglycemia unawareness.

Dual self-regulated delivery of insulin and glucagon by a hybrid patch.

Reduced ß-cell function and insulin deficiency are hallmarks of diabetes mellitus, which is often accompanied by the malfunction of glucagon-secreting α-cells. While insulin therapy has been developed to treat insulin deficiency, the on-demand supplementation of glucagon for acute hypoglycemia treatment remains inadequate. Here, we describe a transdermal patch that mimics the inherent counterregulatory effects of ß-cells and α-cells for blood glucose management by dynamically releasing insulin or glucagon. The two modules share a copolymerized matrix but comprise different ratios of the key monomers to be "dually responsive" to both hyper- and hypoglycemic conditions. In a type 1 diabetic mouse model, the hybrid patch effectively controls hyperglycemia while minimizing the occurrence of hypoglycemia in the setting of insulin therapy with simulated delayed meal or insulin overdose.

Glucose-Responsive Composite Microneedle Patch for Hypoglycemia-Triggered Delivery of Native Glucagon.

Insulin-dependent patients with diabetes mellitus require multiple daily injections of exogenous insulin to combat hyperglycemia. However, administration of excess insulin can lead to hypoglycemia, a life-threatening condition characterized by abnormally low blood glucose levels (BGLs). To prevent hypoglycemia associated with intensive insulin therapy, a "smart" composite microneedle (cMN) patch is developed, which releases native glucagon at low glucose levels. The cMN patch is composed of a photo-crosslinked methacrylated hyaluronic acid (MeHA) microneedle array with embedded multifunctional microgels. The microgels incorporate zwitterionic moieties that stabilize loaded glucagon and phenylboronic acid moieties that provide glucose-dependent volume change to facilitate glucagon release. Hypoglycemia-triggered release of structurally unchanged glucagon from the cMN patch is demonstrated in vitro and in a rat model of type 1 diabetes (T1D). Transdermal application of the patch prevented insulin-induced hypoglycemia in the diabetic rats. This work is the first demonstration of a glucose-responsive glucagon-delivery MN patch for the prevention of hypoglycemia, which has a tremendous potential to reduce the dangers of intensive insulin therapy and improve the quality of life of patients with diabetes and their caregivers.