The authors aimed to introduce a medical application for nonwoven fabric as spacers in particle therapy. Particle therapy, exhibiting more focused effects on target tissues, has emerged as a promising treatment modality. However, close proximity of tumor tissue and adjacent organs makes delivery of curative doses to the tumor difficult because severe radiation morbidities might occur. A method using surgically placed GORE-TEX sheets as a spacer has been reported. Although this method provides for separation of adjacent organs, the material is not resorbed. To overcome these anatomical and therapeutic difficulties, and to deliver effective radiation doses to treat upper abdominal tumors, we have developed a nonwoven fabric spacer composed of bioabsorbable suture material. The absorbable polyglycolic acid (PGA) spacer had water-equivalent, biocompatible, and thickness-retaining properties. Although further evaluation is warranted in a clinical setting, the PGA spacer may be effective to block particle beams and to separate normal tissues from the radiation field. These findings suggest that the nonwoven-fabric PGA spacer might become a useful device in particle therapy.
Part of the book: Non-woven Fabrics
Pancreatic islets contain beta cells which produce insulin based on the blood glucose levels resulting in tight control of blood glucose levels. In type 1 diabetic patients, most of the beta cells are destroyed, therefore, pharmaceutical insulin injection is mandatory to avoid diabetes-related illness and death. Even with recent advanced insulin therapy, hypoglycemia is a critical limiting factor to control blood glucose levels. There is no doubt that hypoglycemia can be fatal. Allogeneic islet transplantation can prevent severe hypoglycemia and provide excellent blood glucose control. On the other hand, allograft donor shortage is the major issue. To overcome donor shortage, xenograft has been used and shown safety and efficacy. Recently stem-cell-derived beta cells are clinically applied. In this chapter, the history and current status of allogenic islet transplantation and future scope are described.
Part of the book: Recent Scientific and Therapeutic Advances in Allograft