An effective method to release human islets from surrounding acinar cells with agitation in high osmolality solution

Area of Science:

• Endocrinology
• Cell Biology
• Surgical Techniques

Background:

• Islet purification is crucial for transplantation and research.
• Density gradient methods are standard but struggle with embedded islets due to similar densities with exocrine tissue.
• High ratios of embedded islets negatively impact purification efficiency.

Purpose of the Study:

• To assess the relationship between embedded islet ratio and purification efficacy.
• To develop and test a novel method for dissociating embedded islets from surrounding exocrine tissue.

Main Methods:

• Chart review of human islet isolation to correlate embedded islet ratio with purification success.
• Testing a new method involving gentle agitation of embedded islet-enriched fractions in high osmolality University of Wisconsin (UW) solutions (400, 500, 600 mOsm/kg/H2O) at 4°C.
• Assessment of islet yield, percentage of embedded islets, and viability at various time points (15, 30, 60 minutes).

Main Results:

• A high embedded islet ratio significantly reduced purification efficacy.
• High osmolality solutions (500 and 600 mOsm/kg/H2O) effectively reduced the percentage of embedded islets to <20% within 15 minutes.
• Islet viability remained >95% in all tested groups at 30 minutes, with optimal dissociation achieved at 500 mOsm/kg/H2O.

Conclusions:

• Embedded islets present a significant challenge to effective islet purification.
• Gentle agitation in a 500 mOsm/kg/H2O solution for 15 minutes is an effective method to release islets from surrounding exocrine tissue.
• This optimized method improves islet isolation by addressing the issue of embedded islets.