Design, fabrication and physical characterization of scaffolds made from biodegradable synthetic polymers in combination with rp systems based on melt extrusion

Abstract

The more recently coined term "Regenerative Medicine" represents a shift in emphasis from current methods to replace tissues with medical devices and artificial organs to more biological approaches which focus on regeneration rather than replacement or repair. Regenerative medicine envelops several biomedical fields; however it can be argued that cell therapy and tissue engineering are on the forefront in the twenty-first century. It can be argued that the beginning of the "scaffold-based tissue engineering concept"-as we know it today-was in the mid-1980s when the pediatric surgeon J. Vacanti of the Children's Hospital approached the chemical engineer R. Langer of MIT with an idea to design scaffolds for cell delivery as opposed to seeding cells onto or mixing cells into available naturally occurring matrices having physical and chemical properties that was difficult to be manipulated, thus resulting in wide variations of the results produced in vitro and in vivo. Today's scaffold-based tissue engineering concepts involve the combination of viable cells, biomolecules and a scaffold to promote the repair and/or regeneration of tissues as depicted schematically in Fig. 12.1. The science behind engineering tissue engineered constructs (TEC) is still under intense investigation and various approaches and strategies are currently developed by a plethora of tissue engineering laboratories and institutes around the globe. However, after studying the scaffold literature it must be concluded is by no means clear what defines an ideal scaffold/cell or scaffold/neo-tissue construct, even for a specific tissue type (Hutmacher et al., 2007). The considerations are complex and scaffolds in tissue engineered constructs will have certain minimum requirements for biochemical as well as chemical and physical properties. These include biocompatibility, angiogenesis, vascularisation and chemotaxis issues, the scaffold must not be an agent for allergic reaction and disease transmission, it must posse's suitable gross architectural qualities able to be produced via a reproducible processing platform. There are also sterilization and administrative issues to contend with.© Springer 2008.