# A Bioartificial Device for the Encapsulation of Pancreatic β-Cells Using a Semipermeable Biocompatible Porous Membrane

## TL;DR

This paper introduces a new device to encapsulate pancreatic β-cells using a semipermeable membrane, aiming to treat Type 1 diabetes without immunosuppression.

## Contribution

A novel spiral tubular encapsulation device using PES membrane and resin scaffold is developed for high-density β-cell encapsulation.

## Key findings

- The device maintained high viability and insulin secretion of islet-like spheroids for 48 hours.
- The device can encapsulate up to 356,000 islet equivalents in a single capillary fiber.
- The PES membrane provided mechanical stability and biocompatibility without hindering nutrient and oxygen exchange.

## Abstract

Background/Objectives: Type 1 diabetes (T1D) is a chronic autoimmune condition characterized by the destruction of pancreatic β-cells, leading to insulin deficiency. Current therapies, such as islet transplantation, face significant challenges, including limited donor availability and the need for lifelong immunosuppression. Encapsulation technologies offer a promising alternative, providing immune protection and maintaining β-cell viability. In this study, we propose an encapsulation device featuring a spiral tubular semipermeable polyethersulfone (PES) membrane reinforced with a rigid biocompatible resin scaffold. Methods: The PES membrane was engineered with a tailored porosity of 0.5 µm, enabling efficient nutrient and oxygen exchange while preventing immune cell infiltration. Using INS-1E insulin-secreting cells aggregated into size-controlled islet-like spheroids (ILSs), we evaluated the device’s performance. Results: The device achieved high ILS viability and insulin secretion over 48 h at therapeutic densities, maintaining functionality comparable to free-floating ILSs (control). The PES membrane, with its mechanical stability and biocompatibility, ensured durability without compromising diffusion dynamics, overcoming a critical limitation of other encapsulation approaches. Importantly, the device geometry allowed for the encapsulation of up to 356,000 islet equivalents (IEQs) in a single capillary fiber, reaching therapeutic thresholds for T1D patients. Conclusions: this device, with its innovative design, enables high-density encapsulation while preserving ILS functionality and scalability, making it a potential platform for clinical application. This work highlights the potential of PES-based encapsulation devices to overcome key barriers in T1D treatment, paving the way for personalized, long-term solutions to restore insulin independence.