A Combined Continuous Density/Osmolality Gradient for Supplemental Purification of Human Islets

Area of Science:

• Endocrinology
• Transplantation Biology
• Biotechnology

Background:

• Islet purification is crucial for safe islet transplantation, minimizing risks of portal vein infusion.
• Standard islet purification methods can lead to a significant loss of recovered islets from digested tissue.

Purpose of the Study:

• To evaluate the efficacy of supplemental purification (SP) following regular purification (RP) to improve islet recovery rates.
• To assess the impact of SP on islet viability and function in vitro and in vivo.

Main Methods:

• Developed SP using a combined continuous osmolality/continuous density gradient with tailored low- and high-density solutions.
• Adjusted solution densities (1.075-1.110 g/cm³ / 400-410 mOsm/kg and 1.090-1.125 g/cm³ / 495-505 mOsm/kg) based on RP outcomes.
• Quantified islet recovery percentage and assessed islet viability and function post-SP.

Main Results:

• Regular purification (RP) yielded a 77.3 ± 5.6% islet recovery.
• Supplemental purification (SP) increased islet recovery to 85.3 ± 5.4%.
• In vitro and in vivo assessments confirmed no adverse effects on islet viability and function from SP.

Conclusions:

• Supplemental purification effectively increases islet recovery by approximately 8%.
• The combined continuous density and osmolality gradient for SP is efficient in improving islet equivalents.
• SP offers a viable strategy to enhance islet yield for transplantation without compromising quality.