Gabriela Grigorescu and David Hunkeler Introduction

One of the most powerful group of chemicals in the body are organic compounds collectively referred to as hormones. The glands responsible for the production and release of hormones comprise the endocrine system. Endocrine activities have been identified in certain organs, such as the heart, kidneys, duodenum, liver and the islets of Langerhans in the pancreas (which contains the insulin gland), which are normally associated with other system functions. There have been numerous attempts to...

Polymer Material Purification Sterilization and Endotoxin Deactivation

Many commercially available polymers contain impurities which exhibit adverse biological activities and thus may contribute to failure of an allo- or xenograftic implant. These impurities are of several kinds, including monomers, catalysts, and initiators, which are present in synthetically derived polymers. They can usually be removed via dialysis due to their small molecular size. Pyrogens represent the second kind of impurities. They belong to a group of natural compounds of certain...

Microencapsulation Technology

The methods used for microcapsule formation have been recently reviewed.77 The most widely used procedure involves the gelation of charged polyelectrolytes around the cell core.78 The popular alginate-L-polylysine microcapsules, for example, are obtained in the following sequence 1. the cells are embedded in alginate droplets with the aid of a droplet generator (air liquid jet or an electrostatic generator) 79 2. the droplets are transformed into rigid beads by inducing cross-linking with...

Case Study Insulin Production Systems

Type I diabetes mellitus is a disorder affecting over 80 million people worldwide. At present exogenous insulin delivery via injection or pumps equipped with glucose sensors cannot provide the minute-to-minute normoglycemia needed to prevent the complication associated with this autoimmune disorder. The sensor pump technology also lacks durability, with device function often limited to only hours. The exacting requirement placed on insulin dosage and timing of administration in diabetic...