3.1 The need for standards regarding TEMPs has also prompted a need for definitions. This terminology sets forth definitions of the most commonly used terms and specifies the relationship among the sciences and components applied in tissue engineering to develop TEMPs. Use of these terms and an understanding of these relationships will unify the ASTM TEMPs standards with a common language such that the users of these standards can understand and interpret the standards more precisely. Terms specific to a TEMP standard will also be defined within the respective standard as appropriate.

3.2 Defining Terms-Terms are defined with a broad scope to encompass these new products known as TEMPs. For instance, the definition for somatic cell therapy as stated in the "Guidance for Human Somatic Cell Therapy and Gene Therapy" (1)3 is recognized in this terminology. However, for the purposes of TEMPs that contain cells, we have added the definition of "cell" which is much broader and not limited to the use of living cells.

3.3 Clinical Effects of TEMPs-The users of this terminology should note that terms used regarding the clinical effects of TEMPs, for instance, "modify or modification" of the patient's condition, may also be interpreted to "enhance, augment, transform, alter, improve, or supplement." Similarly, "repair" may also serve to mean "restore."

3.4 The diagram in Fig. 1 shows the relationships of components of TEMPs and of the fields of science (for example, technologies and principles) used in tissue engineering to create TEMPs. Certain TEMPs may be tissue engineered or produced in vitro by using specific components and sciences to create an off-the-shelf TEMP for the users. Other TEMPs may by design require the users to place the components inside the patient, (that is, in vivo) to rely upon the patient's regenerative potential to achieve the product's primary intended purpose. The expectation of a TEMP used for therapeutic clinical applications is to have a therapeutic effect, specifically to repair, modify or regenerate the recipient's cells, tissues, and organs or their structure and function. Such a TEMP may be used for human and non-human applications. In other applications, a TEMP may be used in diagnostic clinical applications, or both, to achieve an investigative outcome of the function of the cells, tissues, and organs.

FIG. 1 Relationships of the Fields of Tissue Engineering to Tissue Engineered Medical Products