Time: Thursday & Friday, November 8th & 9th, 2:00 p.m.
Location: Aggarwal Lecture Hall, Room 130
Polymer Engineering Academic Center
250 South Forge Street, Akron, OH 44325-0301
Lectures Are Free And Open To The Public
The needs for repair and replacement of damaged and diseased tissues and organs are pressing and imperative. Synthetic biomaterials and medical devices have attempted to address these needs. The use of synthetic materials for medical devices and implants has a modern history extending back some 60 years. The materials used have largely been derived from commercial/commodity materials modified to demonstrate acceptable toxicology. Such materials (examples: silicone elastomers, fluoropolymers, polyurethanes and Dacron) have advantages of desirable mechanical properties and biodurability, though generally their biological performance is sub-optimal. Particular problems are chronic (low level) inflammation, fibrosis, thrombosis, calcification and infection. The response of the body to such materials implanted in most tissue spaces is a fibrotic, avascular capsule walling the material from the body. Furthermore, this response is characteristic of chronic inflammatory reaction with activated macrophages, even years after implantation.
More recently, biomaterials design has asked questions about normal biological healing and how surfaces and materials might mimic or attenuate the normal biological processes. Proteins and biomolecules on surfaces and in scaffolds have been explored in biomaterials, tissue engineering and regenerative medicine to induce healing and reconstruction. However, most often, these proteins have been non-specifically immobilized or incorporated into materials with no concern for their orientation or conformational stability. Here we discuss the positive outcomes that come from using engineered surfaces to specifically control protein orientation and conformation with the goal to deliver desired signals to cells. In addition, the use of polymer architecture (precision porosity) to control cells will also be discussed and in vivo healing data presented. These methods offer the potential for much improved healing and integration of prostheses and also directly contribute to tissue engineering.
This talk will present results from two University of Washington tissue engineering projects focused on heart muscle and esophagus. There are foundation technologies and concepts that underlie the engineering of these two very different tissues (and, in fact, all tissues). These foundations are: angiogenesis, innervation, surgical integration, appropriate biomechanics, inflammation/healing, cell sources and market realities. In the context of heart muscle and esophagus, these necessities will be discussed. In particular, the use of instructive scaffolds and biological surface signals to achieve many of these goals will be presented. Two types of scaffolds will be demonstrated. One is made by sphere-templating and has pores that are uniform in size. The other is made by decellularization of esophagus. Other technologies used in conjunction with the scaffolds to achieve the objectives will be presented. Finally, a discussion of the commercialization aspects of tissue engineering will be made, for unless an appropriate business model is arrived at, there will be little or no clinical application of tissue engineering.