Beta-O2 ßAir bioartificial pancreas (oxygen-refueled macrocapsule)
Beta-O2 Technologies Ltd.
A macroencapsulation device that addresses encapsulation's classic weakness — oxygen starvation — by building in a refillable oxygen tank that is topped up daily. In a Phase 1 trial, implanted human islets survived for months behind the membrane with no immunosuppression, but insulin output was too low to affect blood sugar, exposing how hard it is to keep enough cells alive in a capsule.
The scorecard
Implantation successfully prevented immunization and rejection of allogeneic islets without any immunosuppressive therapy — the membrane provided real local immune isolation.[1]
Only minute levels of circulating C-peptide were seen, with no impact on metabolic control; the device came nowhere near reducing insulin needs.[1]
Islets survived for several months behind the membrane, but fibrosis with immune cells formed around the capsule and recovered devices showed blunted insulin response and amyloid formation.[1]
The device is retrievable, but it is a bulky surgical implant whose oxygen port must be refilled with gas daily, adding a substantial maintenance burden.[1]
Demonstrated only in a small Phase 1 cohort of adults with long-standing type 1 diabetes; the device footprint and daily oxygen refills would constrain broad use.[2]
A completed Phase 1 study published in a peer-reviewed journal with a follow-on pilot registered, but human function never reached a level that would justify advancing as a therapy.[1]
The full picture
Macroencapsulation — sealing many islets behind one semi-permeable membrane — is conceptually simple but fights a brutal problem: cells packed together quickly run out of oxygen. The Beta-O2 ßAir device tackles this head-on with an engineered solution: islets are embedded in alginate behind a PTFE membrane, and the device carries a built-in, refillable oxygen reservoir that the patient tops up daily to keep the cells alive.
In a Phase 1 study at Uppsala, four adults with type 1 diabetes received one or two ßAir devices, each holding roughly 155,000–180,000 islet equivalents, monitored for three to six months. The encouraging finding was immune isolation: the membrane prevented immunization and rejection of the donor islets with no immunosuppressive drugs at all, and beta cells survived inside. The disappointing finding was function: only minute amounts of C-peptide reached the bloodstream, with no effect on blood-sugar control. Recovered devices showed a blunted insulin response, fibrotic tissue with immune cells around the capsule, and amyloid in the endocrine tissue.
The device is retrievable and proved the membrane could protect cells, but the results crystallize encapsulation's core tension — even with active oxygenation, keeping enough cells alive and freely secreting insulin through a barrier remains unsolved. It stands as an instructive research platform rather than a near-term therapy.
Coming soon
ETA · Phase 1/2 pilot (NCT02064309); device function in humans remained too low for metabolic benefit, so this is a research-stage platform
Sources
- [1]Carlsson PO, Espes D, Sedigh A, et al. Transplantation of macroencapsulated human islets within the bioartificial pancreas βAir to patients with type 1 diabetes mellitus. Am J Transplant. 2018;18(7):1735-1744 (PMID 29288549, via PubMed). · peer-reviewed · 2018-02-02
- [2]Transplantation of Macro-encapsulated Human Islets Within the Bioartificial Pancreas Beta-Air in Patients With Type 1 Diabetes Mellitus · registry · 2026-04-28