William J. Arnold, M.D.
Medical Director
Dr. Arnold held the full-time position of Vice President and Medical Director of ABS between July 1997 and July 2002. He now continues in the role of Medical Director as a consultant to the Company. Dr. Arnold is board certified in internal medicine and rheumatology. He is practicing rheumatology as a Partner in the Illinois Bone and Joint Institute in Chicago, Illinois. Prior to 1997, Dr. Arnold served as Chairman of the Department of Medicine at Lutheran General Hospital in suburban Chicago. Dr. Arnold has an active, ongoing research interest in the pathogenesis and minimally-invasive therapy of osteoarthritis of the knee. He is the founding president of the Advocate Medical Group, a 270 member physician multi-specialty group in Chicago. Dr. Arnold has served on the Board of Directors of two large integrated delivery systems, Advocate Healthcare in Oak Brook, Illinois, and Allina Hospitals and Clinics in Minnetonka, Minnesota.

Warren Bielke
Chairman
Mr. Bielke became a director of ABS in 1996. Prior to joining ABS, Mr. Bielke was a Founder, President and Chief Executive Officer of InStent, Inc., a medical device manufacturer that was acquired by Medtronic Inc. in 1996. From 1980 to April 1991, when he left to co-found Instent, Mr. Bielke held positions of increasing responsibility in sales and marketing at Pentax Precision Instrument Corporation, a medical instrument company, most recently serving as Executive Vice President and a member of its Board of Directors from October 1989 to April 1991. Prior thereto, Mr. Bielke held various medical products sales and marketing positions at Xomed Medical from 1975 to 1979 and at Baxter Travenol Health Care from 1970 to 1975.

Jeffrey C. Felt, M.D.
CTO
Dr. Jeffrey Felt is board certified in Internal Medicine and Rheumatology. He is a founding fellow of the American College of Rheumatology. He was a managing partner of a large rheumatology private practice until 1995. Dr. Felt founded ABS in 1994 and brought the company to full operation in 1997. In 1998, he founded Disc Dynamics, Inc. which was spun out as a separate company in August of 2000. In 2005, he founded Vertebral Technologies, Inc., a majority owned subsidiary of ABS. Dr. Felt is the lead author on many of the ABS, DDI and VTI patents.

Jeffrey Joseph
Mr. Joseph presently serves as Managing Partner of Prescient Capital, LLC, a boutique private equity, investment banking firm that focuses on venture and early stage healthcare, biotech and medical device companies. In addition, he currently serves as Chief Investment Officer of the Natomas Fund, a multi-strategy, multi-manager, hedge fund of funds with a bias towards long/short healthcare managers. Mr. Joseph is a twenty-five year veteran of the investment industry with extensive buy and sell side experience in both traditional and alternative investments. He previously was Managing Director of Alternative Strategies at Rydex Investments and hedge fund industry consultant Hedge Fund Research. Mr. Joseph's industry commentaries have appeared on CNBC and in The Financial Times, The Wall Street Journal, The New York Times, Investment News, Global Investment, Dow Jones, Pensions and Investments, Bloomberg Wealth Manager, Hedge Fund Alert, Medical Economics, Alternative Investment News and other prominent publications. He is the author of "Hedge Fund Focus," a monthly investment column for Investment Advisor Magazine.

William N. Kelley, M.D.
Dr. Kelley became a director of ABS in 2001. He currently serves on the Board of Directors of Merck & Co. and Beckman Coulter, Inc. and as a trustee of Emory University and the Emory Health Care System. In 1989, Dr. Kelley was named Executive Vice President of the University of Pennsylvania and Dean of the School of Medicine. He became Chief Executive Officer of the University of Pennsylvania Health System when it was established in 1993. From 1975 to 1989, Dr. Kelly was the John G. Searle Professor and Chair of the Department of Internal Medicine at the University of Michigan. Prior to 1975, Dr. Kelley was Professor of Medicine and Chief of the Division of Rheumatic and Genetic Diseases at Duke University Medical Center.

David R. Lorenzi
President and Chief Executive Officer
David joined Advanced Bio-Surfaces, Inc. in September 2007 as its President and Chief Executive Officer. Prior to joining ABS, David served as President and Chief Executive Officer for both OMNI life science, Inc. and PLUS Orthopedics USA, Inc., companies that focus on the orthopedic segment of healthcare, primarily with joint reconstruction products. In addition to OMNI life science and PLUS Orthopedics, David has also held various field, senior and executive level management positions with companies including Ethicon, Orthofix, EMPI and Medtronic. David received his B.S. in Business Administration from West Virginia University in Morgantown, West Virginia. He has participated as a member of the Board of Directors of PLUS Orthopedics, Inc., OMNI life science, Inc. and Enztec, Ltd. He has also held previous board positions with Youth Education in the Arts and has been an Advisor to the San Diego chapter of Heart to Heart International.

Glen D. Nelson, M.D.
Dr. Nelson became a director of ABS in 1999. He is currently Chairman of GDN Holdings, LLC. Dr. Nelson was a member of the Board of Directors of Medtronic, Inc. from 1980 until 2002 and Vice Chairman from 1982 until he retired in 2002. Prior to joining Medtronic, Dr. Nelson practiced surgery from 1969 to 1986. He was Chairman, President and Chief Executive Officer of Park Nicollet Medical Center, a large multi-specialty group practice in Minneapolis from 1975 to 1986. He was also Chairman and Chief Executive Officer of American MedCenters, Inc. from 1984 to 1986. He currently serves on numerous boards of directors, including Carlson Holdings, Inc., St. Paul Companies and Minnesota Public Radio.

Michael Purnell, M.D.
Dr. Purnell is a board certified orthopaedic surgeon in private practice in Modesto, CA. He received his orthopaedic training at Boston University, under the direction of Robert Leach, M.D. He completed a postgraduate trauma and reconstruction fellowship in Munich, Germany, with Professor Berndt Claudi, and a sports medicine fellowship in Sydney, Australia, with Dr. Mervyn Cross. He was a founding member of Orthomed Center, a comprehensive orthopaedic surgery group, and recently oversaw construction of a completely integrated orthopaedic office facility; offering patient care, MRI, physical therapy, outpatient surgery, pharmacy, and orthotic management. He has been a clinical consultant for Alaron Surgical Products, developing a total knee arthroplasty and currently is a consultant for DePuy. He is a member of the editorial review staff of American Journal of Sports Medicine. He has performed over 3,000 reconstructive knee surgeries in his 15 years of professional practice.

David J. Raab, M.D.
Dr. Raab is a board certified orthopaedic surgeon and a fellow of the American Academy of Orthopaedic Surgeons. Dr. Raab attended the University of Michigan (Phi Beta Kappa) and completed medical school at Northwestern University Medical School. He completed his internship and residency in orthopaedic surgery at Northwestern University Medical School and was appointed chief resident in his final year. He also completed a sports medicine fellowship at Minneapolis Sports Medicine Center. Dr. Raab is presently in private practice and is one of the original founders of Illinois Bone and Joint Institute in Chicago, an 80 member orthopaedic/musculoskeletal group. His academic appointments include Assistant Professor at Northwestern University Medical School, Department of Orthopaedic Surgery. Dr. Raab is the Chief Executive Officer of Illinois Sports Medicine and Orthopaedic Surgery Center, LLC.