LAUSANNE, Switzerland, IRVINE, CA, USA – May 22, 2006 - IsoTis S.A., the
orthobiologics company (SWX/Euronext: ISON; TSX: ISO), today announced the
election of Prof. Barbara D. Boyan to its Board of Directors at its annual
general shareholders meeting held on May 18.

Dr. Barbara D. Boyan is a professor in the Wallace H. Coulter Department of
Biomedical Engineering at the Georgia Institute of Technology and at Emory
University, where she holds the Price Gilbert, Jr. Chair in Tissue
Engineering, both located in Atlanta, Georgia. She is also an adjunct
professor in the Departments of Orthopaedics and Cell Biology at Emory
University Medical School as well as the Schools of Biology and Materials
Science and Engineering at the Georgia Institute of Technology.

Dr. Boyan is a co-founder of OsteoBiologics, Inc. (San Antonio, Texas),
Biomedical Development Corporation (San Antonio, Texas) and Orthonics, Inc.
(Atlanta, Georgia). She is a member of the Board of Directors of
ArthroCare, Inc. (ARTC). Since late 2005, Dr. Boyan has chaired the newly
created Scientific Advisory Board of IsoTis. The Scientific Advisory Board
is comprised of the following people:

Barbara Boyan, Ph.D. – Georgia Institute of Technology, Atlanta, GA, U.S.
Adele Boskey, Ph.D. – Hospital of Special Surgery, New York, NY, U.S.
Arnold Caplan, Ph.D. – Case Western Reserve University, Cleveland, OH, U.S.
Clemens van Blitterswijk, Ph.D. – University of Twente, Enschede, The
Netherlands
Joshua Jacobs, M.D., – Rush University Medical Center, Chicago, IL, U.S.
James Poser, Ph.D. – founder and former CEO of Orquest, Laguna Niguel, CA,
U.S.
Michael Yaszemski, M.D, Ph.D. – Mayo Clinic, Rochester, MN, U.S.

Pieter Wolters, President and CEO of IsoTis, said: “After having worked
with Dr. Boyan as an advisor and Chair of our Scientific Advisory Board, we
are very pleased to welcome her to our Board of Directors. She has an
outstanding academic reputation in her field as well as extensive business
experience. Dr. Boyan will be of immense value to the company during a time
when we are actively working on several product and business development
projects to complement the continued strong growth of our Accell product
line.”

IsoTis has a product portfolio with several innovative and proprietary
natural and synthetic bone graft substitutes on the market and others in
development, an established North American independent distribution network
and an expanding international presence. The company’s main commercial
operations are based out of Irvine, California; its international sales
headquarters is based in Lausanne, Switzerland.

For information contact:
Hans Herklots, Director IR
Tel: +41(0)21 620 6011
E-mail: hans.herklots@isotis.com