Joris van Dongen

334 Chapter 14 potential both in vivo as well as in vitro , such as embryonic stem cells, induced pluripotent stem cells as well as satellite cells, neuronal stem cells and intestinal stem cells. 35-38 Second, stem cells have the ability of multipotent cell differentiation. 37 In contrast, stromal cells have a limited lifespan, with a limited proliferation potential and at higher passages ASCs undergo senescence. Thus, the term mesenchymal stem cells is in fact incorrect; it should be named mesenchymal stromal cells. Nevertheless ASCs, irrespective of proliferation, are able to differentiate (be constructive), secrete growth factors and cytokines (be instructive), and can remodel the extracellular matrix (be reconstructive). 39 Although, recently, in literature the word “stem” cell has been replaced by “stromal” cell, clinicians still use the word “adipose stem cell” in their communication with their patients. Reason for this continuing use of the word “stem cells” probably is because people have more confidence in the word “stem” cells rather than “stromal” cells. Moreover, stem cells are associated with the beginning of life and therefore a rather “magical” meaning is attributed to this word. Basically, we all start as a single totipotent stem cell i.e. the fertilized oocyte, which develops towards a human being. Actually, embryonic stem cells are a culture artefact because these are derived from the inner cell mass of a blastocyst, which normally develops to form the three embryonic germ layers (mesoderm, endoderm and ectoderm). 40 In this process of development, all cell types in the body arise from stem cells that comprise the inner cell mass. Because stem cells play a key role in the development of early life, it is easy to believe that so called “stem cells” ( i.e. actually stromal cells) are also able to extent life by regeneration of damaged tissue (damage of pathological nature like osteoarthritis or dermal scarring and damage of physiological nature such as aging of the skin). Patients as well as clinicians and researchers might magically think and hope that ASCs are the solution to every medical problem and hopefully extent life. However, clinicians and researchers should understand and realize (based upon their access to the knowledge) that if the application of ASCs or lipofilling is indeed beneficial, it is merely based upon thoughts and believe. In contrast, patients do not have access to such knowledge and are not well-grounded and therefore fully rely on their clinicians.