Combined Effects for Improved Tissue Dissociation

DESCRIPTION (provided by applicant): Islet cell transplantation offers the hope of a cure for the more than 1 million Americans who are type I (insulin dependant) diabetics. However, current methods of islet cell recovery from donor pancreata leave much room for improvement. To help improve this procedure, EnteraTech, Inc., in collaboration with The University of Cincinnati, is developing a novel islet cell dissociation system. The overall objective of the Phase I work will be to demonstrate a combination of processing factors which should bring substantial improvement to current methods for dissociating pancreata into viable islets for transplantation. The team proposes to demonstrate this improvement through the combination of three processing approaches: 1. Tissue preprocessing (consistent thin sectioning). Both the surface area available to the collagenase enzyme for digestion, and the distance from the tissue surface to the inner-most cell, are factors affecting the enzyme contribution to the process. Tissue preprocessing should maximize enzyme effectiveness while also minimizing total cell exposure time. 2. Addition of energy. Ultrasound will be used to accelerate the dissociation process. Cavitation from ultrasonic energy will accelerate the dissociation process and potentiate the action of the enzyme by driving local mixing. Both direct-contact application of ultrasound, with a probe, and indirect application, immersing the tissue in an excited bath, will be evaluated. 3. Aeration. Aeration will keep the cells more viable by assuring a better supply of oxygen. Appropriate aeration should also add to the beneficial effects of cavitation by providing seeding bubbles and moderating their speed of collapse. The individual and combined effects of these novel processes will be tested and compared against the current computer controlled implementation of the Edmonton Protocol currently in use at The University of Cincinnati.