Plastic and Reconstructive Surgery • February 2015 A Novel and Effective Strategy for the Isolation of Adipose-Derived Stem Cells: Minimally Manipulated Adipose-Derived Stem Cells for More Rapid and Safe Stem Cell Therapy
DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication.
Sir:
W
e applaud the report of Raposio et al.1 of a simple, inexpensive process using vibration and centrifugation to isolate adipose-derived stem cells without a collagenase. Safe and reliable cell isolation methods at the point of care are necessary to bring the benefits of cellular technology to common clinical practice. Contrary to the authors’ conclusions, however, their report confirms previous work showing that mechanical methods are not capable of releasing collagen fibers that tightly bind adipose tissue cells together. Only collagenase efficiently allows isolation of a purified population of pluripotential cells from other cell types and lipoaspirate detritus. The authors report an average yield from three 80-g samples of approximately 6250 cells/g of lipoaspirate, representing approximately 5 percent of the total cells in the isolate without mention of viability. This yield compares to 100,000 viable cells per gram of lipoaspirate isolated with a collagenase-based manual method2 and 250,000 viable cells per gram isolated by the Cytori Celution device (Cytori Therapeutics, Inc., San Diego, Calif.). Furthermore, residual enzyme levels of cell suspensions obtained by automated Celution processing were assayed and found to contain levels of activity far below that initially required to digest tissue, and therefore no safety risk from enzyme use is present before cells are reinjected.3 We agree with Dr. Raposio et al. that collagenase-based methods require more time and expense than mechanical techniques. Most collagenase processes require approximately 90 minutes, and costs range from $400 to $2500 to process 300 to 600 g of lipoaspirate. We commend Dr. Raposio et al. for encouraging the clinical use of adipose-derived stem cells with their interesting article. Mechanical separation techniques may be appropriate for clinical situations that do not require large cell counts or purification of the preparation, but there is a body of cell biology research that demonstrates the effectiveness of collagenase-based isolation processes and substantial clinical research supporting the safety of this approach. Before clinical use, we suggest that similar studies be performed for cells obtained by this mechanical method to ensure that they are comparable in safety and efficacy to collagenase-isolated cells. DOI: 10.1097/PRS.0000000000000929
Joel A. Aronowitz, M.D. Cedars Sinai Medical Center
Cloe S. Hakakian, B.S. University Stem Cell Center Los Angeles, Calif. Correspondence to Dr. Aronowitz 8635 West 3rd Street, Suite 1090W Los Angeles, Calif. 90048 [email protected]
454e
REFERENCES 1. Raposio E, Caruana G, Bonomini S, Libondi G. A novel and effective strategy for the isolation of adipose-derived stem cells: Minimally manipulated adipose-derived stem cells for more rapid and safe stem cell therapy. Plast Reconstr Surg. 2014;133:1406–1409. 2. Yoshimura K, Suga H, Eto H. Adipose-derived stem/progenitor cells: Roles in adipose tissue remodeling and potential use for soft tissue augmentation. Regen Med. 2009;4:265–273. 3. Aronowitz JA, Ellenhorn JD. Adipose stromal vascular fraction isolation: A head-to-head comparison of four commercial cell separation systems. Plast Reconstr Surg. 2013;132:932e–939e.
A Novel and Effective Strategy for the Isolation of Adipose-Derived Stem Cells: Minimally Manipulated Adipose-Derived Stem Cells for More Rapid and Safe Stem Cell Therapy Sir:
W
e read with great interest the article entitled “A Novel and Effective Strategy for the Isolation of Adipose-Derived Stem Cells: Minimally Manipulated Adipose-Derived Stem Cells for More Rapid and Safe Stem Cell Therapy” by Raposio et al.1 Foremost, we want to congratulate the authors for this work and this interesting concept. Indeed, these authors demonstrate the possibility of adipose-derived stromal vascular fraction graft without digestion of the tissue by proteolytic enzymes and, more importantly, without expensive specific devices.2 This is the second study that reports this possibility after the recent work conducted by Tonnard et al.3 However, in our opinion, both studies are insufficient for demonstrating that the transplanted cells are mesenchymal stromal cells. Indeed, the authors did not demonstrate the stemness of the injected stromal vascular fraction cells. Mesenchymal stromal cells have been known for four decades and were initially isolated from the bone marrow. Within the adipose tissue, mesenchymal stromal cells called adipose-derived stromal cells were first reported in 2001 by Zuk et al.4 These cells were defined in vitro by several criteria5: 1. Mesenchymal stromal cells can be isolated based on their ability to adhere to the plastic and they are capable of significant expansion and formation of colony-forming cells, referred to as colony-forming unit-fibroblasts. This characteristic was not tested by the authors. 2. Mesenchymal stromal cells are multipotent cells that can differentiate into various cell types derived from the mesodermal lineage (bone, cartilage, and adipose tissue). This characteristic was not tested by the authors.
DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication.
Sir:
W
e applaud the report of Raposio et al.1 of a simple, inexpensive process using vibration and centrifugation to isolate adipose-derived stem cells without a collagenase. Safe and reliable cell isolation methods at the point of care are necessary to bring the benefits of cellular technology to common clinical practice. Contrary to the authors’ conclusions, however, their report confirms previous work showing that mechanical methods are not capable of releasing collagen fibers that tightly bind adipose tissue cells together. Only collagenase efficiently allows isolation of a purified population of pluripotential cells from other cell types and lipoaspirate detritus. The authors report an average yield from three 80-g samples of approximately 6250 cells/g of lipoaspirate, representing approximately 5 percent of the total cells in the isolate without mention of viability. This yield compares to 100,000 viable cells per gram of lipoaspirate isolated with a collagenase-based manual method2 and 250,000 viable cells per gram isolated by the Cytori Celution device (Cytori Therapeutics, Inc., San Diego, Calif.). Furthermore, residual enzyme levels of cell suspensions obtained by automated Celution processing were assayed and found to contain levels of activity far below that initially required to digest tissue, and therefore no safety risk from enzyme use is present before cells are reinjected.3 We agree with Dr. Raposio et al. that collagenase-based methods require more time and expense than mechanical techniques. Most collagenase processes require approximately 90 minutes, and costs range from $400 to $2500 to process 300 to 600 g of lipoaspirate. We commend Dr. Raposio et al. for encouraging the clinical use of adipose-derived stem cells with their interesting article. Mechanical separation techniques may be appropriate for clinical situations that do not require large cell counts or purification of the preparation, but there is a body of cell biology research that demonstrates the effectiveness of collagenase-based isolation processes and substantial clinical research supporting the safety of this approach. Before clinical use, we suggest that similar studies be performed for cells obtained by this mechanical method to ensure that they are comparable in safety and efficacy to collagenase-isolated cells. DOI: 10.1097/PRS.0000000000000929
Joel A. Aronowitz, M.D. Cedars Sinai Medical Center
Cloe S. Hakakian, B.S. University Stem Cell Center Los Angeles, Calif. Correspondence to Dr. Aronowitz 8635 West 3rd Street, Suite 1090W Los Angeles, Calif. 90048 [email protected]
454e
REFERENCES 1. Raposio E, Caruana G, Bonomini S, Libondi G. A novel and effective strategy for the isolation of adipose-derived stem cells: Minimally manipulated adipose-derived stem cells for more rapid and safe stem cell therapy. Plast Reconstr Surg. 2014;133:1406–1409. 2. Yoshimura K, Suga H, Eto H. Adipose-derived stem/progenitor cells: Roles in adipose tissue remodeling and potential use for soft tissue augmentation. Regen Med. 2009;4:265–273. 3. Aronowitz JA, Ellenhorn JD. Adipose stromal vascular fraction isolation: A head-to-head comparison of four commercial cell separation systems. Plast Reconstr Surg. 2013;132:932e–939e.
A Novel and Effective Strategy for the Isolation of Adipose-Derived Stem Cells: Minimally Manipulated Adipose-Derived Stem Cells for More Rapid and Safe Stem Cell Therapy Sir:
W
e read with great interest the article entitled “A Novel and Effective Strategy for the Isolation of Adipose-Derived Stem Cells: Minimally Manipulated Adipose-Derived Stem Cells for More Rapid and Safe Stem Cell Therapy” by Raposio et al.1 Foremost, we want to congratulate the authors for this work and this interesting concept. Indeed, these authors demonstrate the possibility of adipose-derived stromal vascular fraction graft without digestion of the tissue by proteolytic enzymes and, more importantly, without expensive specific devices.2 This is the second study that reports this possibility after the recent work conducted by Tonnard et al.3 However, in our opinion, both studies are insufficient for demonstrating that the transplanted cells are mesenchymal stromal cells. Indeed, the authors did not demonstrate the stemness of the injected stromal vascular fraction cells. Mesenchymal stromal cells have been known for four decades and were initially isolated from the bone marrow. Within the adipose tissue, mesenchymal stromal cells called adipose-derived stromal cells were first reported in 2001 by Zuk et al.4 These cells were defined in vitro by several criteria5: 1. Mesenchymal stromal cells can be isolated based on their ability to adhere to the plastic and they are capable of significant expansion and formation of colony-forming cells, referred to as colony-forming unit-fibroblasts. This characteristic was not tested by the authors. 2. Mesenchymal stromal cells are multipotent cells that can differentiate into various cell types derived from the mesodermal lineage (bone, cartilage, and adipose tissue). This characteristic was not tested by the authors.
