Giovanna DELLA PORTA | Tissue Enginnering

Tissue loss due to trauma, disease or congenital abnormalities is a major health care problem worldwide. When this occurs in the craniofacial region, it induces serious physiological and psychological consequences on patients. Reconstruction of the craniofacial area to its aesthetic and functional level is therefore a desire of affected patients.1 This review addresses the concentrated research effort in methods for oro-facial reconstruction from using medical devices and tissue grafts to a more explicit tissue engineering approach. It is an approach that utilises specific biodegradable synthetic or natural scaffolds as well as advanced molecular techniques in order to replace tissue function. The types of scaffold and methodologies used to enable cells to function in an appropriate manner to produce the required extracellular matrix and ultimately a tissue of a desired geometry, size and composition are briefly considered here. There has been a clear and distinct hypothetical shift in regenerative medicine from using medical devices and whole tissue grafts, to a more explicit approach that utilises specific bioactive, biodegradable synthetic or natural scaffolds combined with cells and/or biological molecules, to create a functional replacement tissue in a diseased or damaged site. Every era in medical research over the past 50 years, involving the use of biomaterials in order to replace tissue function, has been distinct and identified by particular developmental successes and materials. For example, in the 1950s, there was a predominant use of metal implants and associated devices with little thought offered to the effects on local tissues, let alone the cells. Throughout the ‘70s and ‘80s, there was a significant increase in the use of polymers and synthetic materials where researchers considered both biological and material properties. More recently, there has been a distinct and concentrated effort in the design and use of both natural and degradable scaffolds and advanced biological consideration of the materials. There has been an evolution from the use of biomaterials to simply replace non-functioning tissue to that of utilising specific materials, which will nurture, in three dimensions, a fully functioning and structurally acceptable regenerated tissue. Thus, the simple needs to accomplish the replacement of a functioning joint using wholly metal prostheses in the ‘60s has been markedly enhanced to concentrate on biological aspects of the damaged or diseased tissue to be replaced by repaired, or better still, totally regenerated tissue. There was a very naı¨ve belief that materials were typically ‘inert’ and it has been rightly suggested that this is a misleading interpretation, as it became clear that materials could indeed change physically and chemically following implantation. Certainly from a biological perspective, no material should be considered (or indeed is) inert.