Earticle

Transplantation of pancreatic islet is one of therapeutic method of Diabetes Mellitus treatment. Islets, however, lose their ECM (extracellular matrix) during isolation process, and these bare islets clusters are vulnerable not only to attack by immune system but also to physical damage. Alginate capsule can solve these problems by making semipermeable physical barrier. Microencapsulation of islet using alginate was performed through air-driven system. However, this method always produces empty capsules, which cause enlargement of transplantation volume. Previous researchers have done the selection of encapsulated islet by hand-picking. In this research, density-gradient method was applied to separate the encapsulated islets and empty capsules. First, density difference of islets and alginate capsules were confirmed. By adjusting concentration of Percoll®, centrifugation speed and time, optimal conditions for gathering encapsulated islets were set up. Final yield of microencapsulated neonatal porcine islet cell clusters (NPCCs) after process was more than 90%.

As an alternative treatment of Diabetes Melitus, xeno-transplantation of insulin-secreting pancreatic islets has been emerged. Microencapsulation of islets is essential in order to prevent islets from attack of host immune system. However, large amount of empty capsule after microencapsulation process using alginate as a biocompatible material is produced under air-driven system, which causes enlargement of transplantation volume. In this research, empty alginate capsules and encapsulated islets were separated of viability using density-gradient solution. Also, its function and viability were confirmed to check toxicity of density-gradient solution and harmness of separation process.