Encapsulated islets for diabetes therapy: history, current progress, and critical issues requiring solution.

Area of Science:

• Biomedical Engineering
• Endocrinology
• Regenerative Medicine

Background:

• Insulin therapy (1921) improved survival for diabetes but not long-term complications.
• Islet transplantation (1989) requires lifelong immunosuppression.
• Encapsulated islet approaches have been explored for decades without a clinically approved product.

Purpose of the Study:

• To review the current status of encapsulated islet transplantation for diabetes.
• To highlight corporate efforts in developing islet encapsulation technologies.
• To identify critical challenges hindering clinical translation.

Main Methods:

• Review of early and current studies on encapsulated islet approaches.
• Analysis of macro-device and micro-capsule strategies.
• Examination of successes and limitations in animal and human trials.

Main Results:

• Macro-devices show long-term success in large animals, but human trials face challenges.
• Micro-capsules (e.g., alginate) have numerous rodent successes but limited translation to larger animals and humans.
• Reduction of encapsulated islet mass for clinical transplantation is ongoing.

Conclusions:

• Significant progress has been made in encapsulated islet research.
• Critical challenges must be addressed for successful clinical diabetes therapy.
• Further innovation is required to bridge the gap between preclinical success and human application.