Device Insertion Versus Material: Drivers of Inflammation in Diabetes Device Interfaces

Area of Science:

• Biomaterials Science
• Immunology
• Medical Device Engineering

Background:

• Automated insulin delivery (AID) systems are hindered by short insulin infusion set (IIS) wear times (2-3 days), contrasting with longer continuous glucose monitoring (CGM) sensor lifespans (14 days).
• Infusion set failure compromises AID reliability and patient adherence.
• Understanding the inflammatory responses to IIS implantation is crucial for improving AID system performance.

Purpose of the Study:

• To investigate the roles of insertion trauma and biomaterial composition in acute inflammatory responses to insulin infusion sets.
• To compare the biocompatibility of different infusion set materials and CGM sensors.
• To identify strategies for prolonging the wear time of devices used in AID systems.

Main Methods:

• Evaluated three commercial CGM sensors and two Teflon-based IIS catheters in swine and mouse models.
• Assessed neutrophil extracellular trap (NET) formation in swine tissue one day post-implantation.
• Analyzed immune cell infiltration and cytokine expression in murine air pouch models at 1 and 3 days post-implantation.

Main Results:

• Neutrophil extracellular traps (NETs) were present at all insertion sites, indicating insertion trauma as the primary trigger for early NET formation.
• Teflon catheters induced a prolonged inflammatory response, including increased macrophages, mast cells, and TNF-α and KC/GRO levels.
• Polyurethane-based sensors demonstrated minimal immune activation, suggesting superior biocompatibility compared to Teflon.

Conclusions:

• Minimizing insertion trauma is critical for reducing acute inflammatory responses.
• Selecting biocompatible materials, such as polyurethane, can enhance device-tissue integration and prolong wear time.
• Optimizing material selection and insertion techniques can significantly improve AID system reliability and patient outcomes.