Reconstructing tissues using fat stem cells and the thin line between clinical and cosmetic needs
by Michelle Ly
Reconstructive surgery plays an important role in recovery from disease and injury by attempting to restore function or appearance to the body. While the use of synthetic materials is commonplace, the ability to replace or reconstruct using the same tissues from elsewhere in the body is desirable because it would eliminate many issues that occur with synthetic materials, such as higher infection rates and foreign body reactions.
One new technique being investigated in the field of reconstructive medicine uses an adherent, multipotent population of cells called adipose-derived stem cells (ASCs). ASCs are isolated from subcutaneous body fat by taking minced tissue fragments, digesting it with an enzyme called collagenase, and then spinning out the resultant mixture to separate the stem cell containing layer. As a type of stem cell, ASCs can theoretically differentiate into any of the adipose cell lineages, making them an extremely useful tool in regenerative medicine. However, the extent of differentiation in ASCs has been questioned, especially in comparison to standards set by other stem cell populations.
While the supporting technologies in this emerging field are still undergoing development and refinement, some clinical progress has already been achieved. California-based Cytori Therapeutics reported success with a clinical trial to reconstruct breast tissue following breast cancer surgery using what they call “adipose-derived stem and regenerative cells” (ADRCs). The study was conducted across several European health centers and was led by co-principal investigators Dr. Weiler-Mithoff and Dr. Rosa Pérez Cano at the Hospital Universitario Gregorio Marañón in Madrid, Spain. The procedure takes fat from the patient by liposuction and then harvests and processes the ADRCs for inclusion in “cell enriched fat grafts” which are used to reconstruct the breast.
These early successes have not been achieved without criticism however, and some researchers are urging caution in patients and researchers interested in ASC based therapies. In addition to questions about the level of cell differentiation, a recent review pointed to unresolved issues in large-scale engineering and differences in stem cell purity depending on tissue source. Other researchers warn that some studies do not adequately account for the heterogeneity of the ASC population and how that may affect clinical treatments.
With the growing attention to stem cell procedures in recent years and the accompanying rise of marketed stem cell treatments, both clinical and cosmetic, it is more important than ever for patients and their doctors to focus on well-researched studies and trials. As such, future studies in ASC-based treatments will need to address concerns about isolation, purification and differentiation in order to continue with progress in academia and industry.