Use of Adipose-Derived Stem Cells in Regenerative Therapy Use of Adipose-Derived Stem Cells in Regenerative Therapy David Euhus, MD Professor of Surgery UT Southwestern Medical Center at Dallas David Euhus, MD Professor of Surgery UT Southwestern Medical Center at Dallas Pleuripotent Stromal Cells Stem Cell Therapy Concept Common Names Mesenchymal stem cells (BM) Pleuripotent mesenchymal stromal cells (BM) Adipose-derived stem cells Adipose-derived regenerative cells Adipose stromal cells Defining Features Adhere to plastic Self renewing Pleuripotent differentiation Markers CD10 CD13 CD29 CD44 CD49a-f CD63 CD73 CD90 CD105 CD106 CD140b CD146 CD166 CD271 STRO-1 1. Stem cell harvest Bone marrow Adipose Umbilical blood Umbilical cord (Wharton s jelly) Amniotic membranes 2. Stem cells traffic to injury sites 3. Stem cells A. Generate a blood supply B. Secrete beneficial cytokines C. Deliver biomolecules D. Suppress inflammation E. Differentiate into structural and functional components Stem Cell Therapy: Conditions Under Investigation There is a Growing Stem Cell Therapy Industry Ischemic heart disease Type 1 diabetes Neurological disease Hepatic cirrhosis Graft versus host disease Arthritis Numerous registered Phase 1 3 clinical trials Very little published outcome data 1
Medical Tourism Stem Cell Therapy: Observations Mexico Europe China India Croatia Others Most infused stem cells are trapped in the lungs A small fraction of stem cell are detectible in a variety of tissue Stem cells do not directly differentiate into new healthy tissues Stems cells do not persist in the tissues of interest Any observed benefits likely due to Anti-inflammatory effects Secreted factors No published clinical trial data convincingly demonstrating clinical benefit for any condition except: graft versus host disease MI (intracoronary injection of MSC): 6.7% vs. 0.7% increase in LVEF Numerous intriguing testimonials on the internet especially from veterinary practices Prockop DJ, et al. J Cell Mol Med 2010;14:2190-2199 Wollert KC, et al. Lancet 2004;364:141-148 Adipose Stem Cells Issues in Stem Cell assisted Breast Reconstruction Mature fat cells and free fats Stromal-vascular fraction (SVF) AKA adipose-derived stem cells AKA adipose-derived regenerative cells (optional) Centrifuged Liopsuction Material RBCs and Plasma Immunosubtraction to exclude certain cell populations Adipose Stromal-Vascular Fraction A heterogeneous mixture of cell types Adipose contains 100-1000 times more pluripotent cells per cubic centimeter than bone marrow. Can be expanded in culture Can differentiate into Mature adipose Cardiac muscle Smooth muscle Cartilage Bone Nerves Blood vessels Liver Blood cells Central questions concerning adipose-derived stem cell-assisted breast reconstruction: 1. Is it better than free fat transfer alone Effects on breast imaging characteristics Volume retention (durability) 2. Is it oncologically safe? Mosely T, et al. Plastic Recon Surg 2006;118:121S-128S 2
Autologous Fat Transfer 1. Harvest adipose with liposuction 2. Fat Transfer Autologous Fat Transfer for Breast Augmentation and Reconstruction 1895, First described by Czerny 1950, Fell into disfavor Poor graft survival leads to significant volume loss over time. 1987, American Society of Plastic and Reconstructive Surgery bans the procedure for breast augmentation. Fat necrosis interferes with breast cancer detection 1997, Coleman describes lipostructure technique Likely improves graft survival 2007, ASPS and ASAPS issue cautionary statements 2007, French Society of Plastic Aesthetic and Reconstructive Surgery (SOFCPRE) does not support fat grafting following lumpectomy. Chan CW, et al. J Plast Recon Aesth Surg 2008;61:1438-1448 Mojallal A, et al. J Plast Recon Aesth Surg 2009;62:708-710 Autologous Fat Transfer: Radiographic Issues Radiographic and palpable lesions develop over years. Most are clearly benign. BIRADS 3 microcalcifications in ~15% Eur J Surg Oncol 2007;33:685-690 69 patients followed a mean of 11.7 mo Cosmetic outcome good to very good in 86.5%. No suspicious imaging findings Autologous Fat Transfer: Durability Paucity of long term follow-up studies for breast reconstruction Volume loss is estimated at 20 90% in the first year. Highly variable. Ischemic necrosis Apoptosis Dedifferentiation of adipocytes Preparing Adipose-derived Stem Cells 1. Harvest adipose with liposuction 2. Treat adipose with collagenase 3. Centrifuge 4. Isolate Stromalvascular fraction 5. Activate (e.g. platelet-enriched plasma) 6. Inject in combination with mature adipose Yoshimura K. Aesthetic Plastic Surgery 2008;33:48-55 3
Adipose-derived Stem Cells in Breast Augmentation Preop Oncologic Safety of Adiposederived Stem Cells 40 patients Median F/U ~6 mo No comparison without ASC enrichment At least some patients are retaining volume over time. Microcalcifications developed in 5% (at 24 mo) 24 months Co-culture with adipose-derived stem cells (ASC) increased the proliferation of breast cancer pleural effusion cells (5.1-fold) Co-injection of ACS increased tumorigenesis for active (CD90-) breast cancer pleural effusion cells, but not resting (CD90+) cells. Yoshimura K. Aesthetic Plastic Surgery 2008;33:48-55 Zimmerlin L, et al. Tissue Engineering Part A 2011;17:93-106 Oncologic Safety of Adiposederived Stem Cells Co-injection of ASCs increased the tumorigenicity of cancer cell lines (subq and brain) No increase in vascularity Increased viability, reduced apoptosis Conditioned media from ASCs increased proliferation of cancer cells in vitro. Murine Adipose-derived Regenerative Cells and Angiogenesis CD31+ Capillary-like network in vitro Compared to Fat Only Transfer Increased graft integrity at 6 and 9 months. Increased microvessel density Yu JM, et al. Stem Cells Dev 2008;17:463-473 Zhu M. Ann Plastic Surg 2010;64:222-228 Adipose-derived Stem Cells: Secreted Factors VEGF autocrine loop. Exp Opin Biol Ther 2010;10:1529-1537 VEGF, HGF, and TGF-β. Enhanced with hypoxia. Circulation 2004;109;1292-1298 VEGF, IGF-1 Biochem Biophys Res Comm 2007;363:674-679 FDA Policy: Human cells or tissue intended for implantation, transplantation, infusion, or transfer into a human recipient is regulated as a human cell, tissue, and cellular and tissue-based product or HCT/P. The Center for Biologics Evaluation and Research (CBER) regulates HCT/Ps under 21 CFR Parts 1270 and 1271. Are autologous minimally manipulated adipose stem cells considered a drug or a tissue? Where do you draw the line in the sand for minimal manipulation? Embryonic stem cells and cultured adult stem cells have already been designated as a drug by the FDA. The FDA has not yet taken a formal position on autologous uncultured adipose stem cells. 4
Oncologic Safety of Autologous Fat Transfer (without stem cell enrichment) Co-culture of mature fat cells (from rat) but not preadipocytes increased the proliferation of human breast cancer cell lines. J Pathol 2003;201:221-228 880 patients; max f/u 10 years: no increase in local recurrence Aesthet Surg J 2009;29:360 Clinical Trials Autologous Fat Transfer GRATSEC: A randomized prospective multicenter trial to begin in France in the near future. Oncologic safety is a primary endpoint Adipose-derived Stem Cells Cytori is sponsoring a European trial for patients requiring breast reconstruction after lumpectomy for breast cancer. Tissue Engineering Baseline Adipose-derived Stem Cells in the Treatment of Radiation Necrosis After ADSC application After skin grafting Final Rapid and dramatic healing in 19 of 20 patients Sterodimas A, et al, Ann Plast Surg 2009;62:97-103 Rigotti G, et al. Plastic Recon Surg 2007;119:1409-1422 Summary of Stem Cell Therapy It seems unlike that intravenous infusions of stem cells from any source will provide benefits beyond a general antiinflammatory effect. Site-specific delivery of stem cells may prove useful for Wound healing Improved organ function for a variety of conditions Summary of Adipose-derived Stem Cells in Breast Reconstruction Compared to autologous fat transfer alone, is enrichment for ADSCs Associated with a lower frequency of BIRADS 3 mammographic changes? UNKNOWN Associated with better graft survival (i.e. volume maintenance)? UNKNOWN Oncologically safe? UNKNOWN 5