Cellular Polymers for Medical Use: The Vital Role of Porosity and Permeability

Cellular polymers have played a significant role in the development of a base of knowledge for the safe and efficacious use of surgically implantable biomaterials. Inherent compatibility and properties of porosity and permeability are vital attributes for the ingrowth of soft and rigid tissues into select indwelling devices. Such characteristics are necessary for long-term physiological acceptability of vascular grafts and for permanent bone attachment of dental and orthopedic appliances, and for controlled drug release implants. Early experience with sponges of polyvinyl alcohol denatured gelatin collagen and silicone rubber has aided in the establishment of criteria for pore size which have carried over to more recently used foams of polyurethane, polytetrafluoroethylene and polyethylene. Cellular polymers and their composites promise to play an even larger role in health care delivery of the future.