SYNTHETICS VS. BIOLOGICS:

The Stone Age didn't end due to a lack of stones.

As better alternatives become available, the limitations of existing technologies become more apparent and less acceptable. Such a revolution is beginning with the choices for surgical biomaterials used to repair diseased or deficient soft tissues. Traditionally, surgical repair of diseased, deficient or absent tissue relied on transposition of autologous tissue or transplantation of allogeneic tissues to achieve a functional outcome. Albative procedures were an alternative to close a defect while accepting the cosmetic and functional consequences of tissue loss. Last, biomaterial implantation has been used to maintain structure at the cost of function and foreign body inflammation. The possibility of reconstituting both structure and function without transplantation or tissue transposition was not an option—until now. It may be possible to harness the patients' own ability to regenerate tissues that more closely recapitulate functional aspects of replaced soft tissue.

THE CRUX OF THE PROBLEM
Man-made synthetics available for medical purposes are not biological. They are mechanical and physical materials that have been found to be biocompatible, at least in the strictest sense, but they are recognized by the patient's cells as foreign. Therefore, materials that are implanted but cannot be truly assimilated into living tissues serve as a source of chronic inflammation, provide an immunologically indefensible location to harbor pathogens, and continue to be a physical mismatch to their surrounding tissues. A surgery with these materials often leads to another surgery or a chronic problem.

Tissue re-growth process that takes place after the natural biomaterial medical product is implanted.

HARNESSING HEALING
"Guided tissue regeneration" has long been a catch-phrase in biology, and it aptly describes a new class of biomaterials that can recapitulate tissues through conductive and inductive mechanisms. Embryological and regenerative medicine studies have clearly shown that the interplay between cells and the extracellular matrix form the basis for tissue and organ development. Cells, scaffolds and signals become the building blocks for creating functional outcomes in the discipline of Tissue Engineering.

NEW BIOMATERIALS EXIST Wishing for a better solution to foreignbody implants is one thing, but making that desire a reality is quite another. Biology is complex, and the creation of a product that can harness biological processes, rather than compete with biological processes, has been the goal of many companies. Fortunately, today a new class of "biological" materials exists based on the extracellular matrix of harvested tissues. Some are made from human tissues, others are made from animal tissues; in every case, they are, at minimum, focused on tissue conduction through a scaffolding mechanism.

Perhaps even more than their synthetic counterparts, biologic implants require the technical prowess of the surgeon and the medical condition of the patient to be congruent with principles of good tissue repair. Some patients may be of such a compromised physical or metabolic condition as to make them incapable of completely repopulating and healing a biologic implant. Similarly, poor attachment or contact with vascular tissues, excessive tissue motion, or placing a biologic graft in a grossly contaminated field may make graft success much more unlikely. Striking this balance between patient, procedure and product ultimately dictates success or failure of surgery, but longterm results indicate that proper use of biologic grafts can lead to much better outcomes for patients.