Importance to FDA

Regenerative medicine refers to a general approach to restore, replace, or recreate cells, tissues, or organs to treat or mitigate disease. The types of products that FDA regulates in this category include cell therapy, therapeutic tissue engineering products, any combination products using such therapies or products, some gene therapy products, and human cell and tissue products (except for those regulated solely under section 361 of the Public Health Service Act. Regulation of regenerative medicine therapies pose many challenges, some of which are listed below. FDA conducts research to improve and resolve challenges such as the lack of international consensus standards for regenerative product safety and effectiveness.

Examples

One example of a regenerative medicine therapy is a 3D-printed scaffold made of a new biomaterial with cells derived from allogeneic stem cells in vitro. Scaffolds allow multiple cell types to grow on a single implant to speed up tissue growth. This type of product raises scientific questions that affect regulatory evaluation and require evaluation by FDA researchers:

• The use of allogeneic stem cells may present compatibility issues between the living tissue and the 3D-printed implant or an immune response, such as inflammation.
• Product types cannot be sterilized in their final holding container (terminally sterilized), so it is a challenge to also assess sterility of the final product without compromising their structure and function.
• Methods are needed to predict whether the differentiated cells will revert to stem cells or create tumors.
• After implantation of this type of product, there are questions about whether the cells stay in place or migrate to other parts of the body where they may cause harm.
• Physics-based quantitative modalities are needed to assess the quality of regenerated tissue during and after product remodeling upon implantation.
• If the scaffold is designed to resorb (dissolve) at a rate proportional to cell proliferation, additional questions arise about the impact on scaffold structural integrity, biocompatibility of degradation products, cell survival and proliferation, and both structural and functional integrity of the regenerated tissue.