Conference: 1st International Conference on Epithelial Technologies and Tissue Engineering (ICETTE), 4-6 December 2003, Singapore.
Nan Chen (ATIP Technology Analyst)
Epithelial tissues are membranous and they form the covering of most internal surfaces, organs, and the outer surface of animals. Most cancers involve epithelial tissue. The preponderance of research in tissue engineering has focused on cartilage, bone, and cardiovascular tissues. Epithelial tissues have been studied far less. Engineering of epithelial tissues requires unique cell culturing and design concepts to achieve functional tissue-like substitutes. These substitutes must fulfill several functions and are generally composed of two or more cell types.
ICETTE addressed recent advances and current needs for epithelial-cell tissue engineering. Topics included: skin, cornea, oral, intestine, and esophagus tissue engineering; scaffolds and biomaterials; cell structure, stem cells, and cell regeneration; and experimental and surgical techniques and concerns. There were approximately 60 attendees; many were associated with Singaporean institutions or the University of Washington. Singapore's Agency for Science, Technology and Research (A*STAR) now funds two collaborative projects in biomedical engineering between Nanyang Technological University and the University of Washington and the links between the two schools are strong.
In broad strokes, epithelial tissue engineering involves culturing appropriate cells on a scaffold and transplanting the resultant tissue substitute into a host, with drugs being added to facilitate incorporation into the host. Development of each of the three componentsócells, scaffolds, drugs-presents a series of challenges. The cells are often stem cells, which can differentiate as needed to form the desired tissue. One must be able to identify, harvest, and culture these cells. Scaffolds are now made from a variety of synthetic or natural polymers. They should be compatible with the host, and most preferably degraded within the host over a controllable period. They must provide adequate mechanical strength to allow for transplantation. The drugs must be targeted biochemically and spatially.
Advances to date in epithelial tissue engineering have been spectacular. In general, external-surface engineering has achieved greater success in patients than has internal-surface engineering. The inherent complexity of form and function of, for example, an intestine has impeded successful engineering of a substitute. Intestines serve four primary functions: barrier, absorption, motility, and autonomic nerve. Recently engineered small intestines fulfill the barrier and absorptive functions, but tend to be weak and do not provided adequate motility or nerve function.
Papers on surgical techniques and clinical trials covered many successes and addressed needs of current patients. For tissues such as an esophagus or small intestine, surgical replacements are made now. None is fully effective, however, and tissue engineering offers the best hope for millions of people now suffering from tissue damage or inadequate remedial treatment. The rate of recent progress has been striking and further and more impressive successes are likely. A second ICETTE is being planned and, of course, epithelial tissue engineering is covered along with many other topics in more broadly based conferences and topical meetings.
Conference webpage: http://www.ntu.edu.sg/bmerc/icette.html