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TTS 2024 - CTRMS Symposium

CTRMS 2025

October 22-25 | Tokyo, Japan

Back To The Future: Dr. Arnold I. Caplan

  • It is with the highest degree of sadness that I write this brief memorial for my friend and admired colleague, Dr. Arnold I. Caplan of Cleveland, Ohio, who passed away at age 82, peacefully on January 10, 2024, with his loving family by his side.

    Camillo Ricordi, CTRMS Founding President

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My first encounter with Arnold was in 1991, after he published “Mesenchymal Stem Cells (submitted for publication on September 17th 1990). This publication outlined in part the basis for Dr. Caplan’s receiving the 1990 Elisabeth Winston Lanier Award given by the American Academy of Orthopaedic Surgeons as part of the prestigious Kappa Delta Awards. In this historic article, you can appreciate that the entire MSC hypothesis and the Mesengenic Process diagram evolved from Dr. Caplan’s previous 20 years of study of bone and cartilage formation in the limbs of developing chick embryos, while he was also studying in-vivo limb development in mice and humans. While many others studied various aspects of skeletal progenitors, no one ever put together the lineage diagram as Dr. Caplan did in the late 1980s, because no one had a monoclonal antibody approach or data. Indeed, Dr. Caplan and collaborators had already isolated human MSCs and had isolated 3 specific monoclonal cell surface markers, called SH2, SH3, SH4 (these eventually were similar to CD105 and CD73 now considered signatures for hMSCs). Dr. Caplan and collaborators submitted 4 patents in 1990 which eventually served as the basis for starting Osiris, Inc. Eventually, Pittenger and other employees of Osiris repeated all of Dr. Caplan’s early work, cloned hMSCs and documented their multipotency. It was this paper, Dr. Caplan’s Kappa Delta Award and his published work on bone and cartilage which, together with his worldwide lectures, popularized MSCs. The fact that the procedures developed by Dr. Caplan and collaborators from the late 1980s still represent the gold standard of the MSC industry is proof of their widespread reproducibility and utility. I still remembered when I first read Dr. Caplan’s fascinating work which prompted me to invite him to give a plenary lecture at the 1st International Congress of the then neo-formed Cell Transplant Society, in Pittsburgh in 1992. The new science of Pericytes/Medicinal Signaling Cells/MSCs evolved from the expansion of this base technology. These findings subsequently converged with the identification of MSCs from every tissue and the clear documentation of the identity of pericytes with MSCs by Peault and collaborators. While the potential new clinical uses of MSCs continue to expand in experimental and clinical practice, hundreds of clinical trials will help distinguish hype from hope and those that eventually will become established clinical applications as per modern “evidence-based medicine” standards. However, it is also thanks to these innovative pilot clinical trials, in addition to basic science contributions, that the field of regenerative medicine and its applications will continue to evolve, despite the obstacles to innovation and the development of cures that are currently limiting translational research efforts in several countries. (adapted from Ricordi C. BACK TO THE FUTURE – Mesenchymal Stem Cells; CellR4 2013; 1 (2): e405)

Dr. Caplan was born on January 5, 1942 in Chicago, earned his B.S. in Chemistry from the Illinois Institute of Technology and his Ph.D. from The Johns Hopkins University School of Medicine. He joined Case Western Reserve University in 1969, where he steadily rose through the academic ranks, becoming a Professor in 1981 and dedicating an impressive 54 years to the institution.

A pivotal moment in his career came with the isolation of human Mesenchymal Stem Cells (MSCs) from adult bone marrow, establishing the conceptual and technical foundation for subsequent global studies. In 1992, he founded Osiris Therapeutics, Inc., commercializing the technology, which later lead to numerous clinical trials worldwide.

Recognized as the father of both basic science and clinical therapeutics of adult Mesenchymal Stem Cells (MSC’s), Dr. Caplan discovered the innate ability of MSC's to modulate the immune system; inhibit both programmed cell death and scar formation; to stimulate blood-vessel formation; and to promote the growth of tissue-specific stem cells. His work has impacted studies and treatment of various human diseases ranging from Multiple Sclerosis and Osteoarthritis to spinal cord injuries to cancer.

Dr. Caplan's warmth and mentorship touched the lives of countless others he trained—shaping the lives of over 150 researchers with his intellect and guidance. His passion extended to sharing his expertise through influential courses, fostering scientific collaboration globally. Honored with many awards including The Marshall R. Urist Award; The Tissue Engineering and Regenerative Medicine International Society Lifetime Achievement Award; and the Case Western Reserve University Faculty Innovator Award. He has over 400 published papers and 20 patents. His contributions shaped the landscape of regenerative medicine.

Beyond the laboratory, Arnold was a devoted husband, father, grandfather, and friend, creating a legacy that extends far beyond scientific achievements. His love for cooking, walks, and deep, meaningful conversations (which often became debates) will be missed by many.

He leaves behind a tapestry of cherished memories, instilling values of love, wisdom, and warmth in the hearts of those who knew him.

Arnold I. Caplan is survived by his loving wife of 58 years, Bonnie, his two children Aaron (Tami) Caplan and Rachel (David) Uram and six wonderful grandchildren, Josh, Andrew, and Brian Caplan and Lyla, Sam, and Bella Uram and his brother Herbert (Barbara) Caplan. He lives on through the countless lives touched by his pioneering work and unending love for family and friends (adapted from Arnold Caplan Obituary - Cleveland Heights, OH).

For all of us in the field of MSC and regenerative medicine, Arnold remains a distinguished scientist, a mentor, and a pioneer, who left an indelible mark on the field and in our lives, during an amazing career that spanned over five decades, gifting us memories, mentorship and friendship.

Rest In Peace, my friend, you will be greatly missed, but never forgotten, and when MSC treatments will become standard of care, they will have your name written all over them.

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CTRMS Ricordi Lecture from the 2023 IPITA-IXA-CTRMS Joint Congress

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A Message from the President

  • Dear friends and colleagues,

    I am truly honored to be named the 16th President of CTRMS during the 30th anniversary year of the organization with a long and rich history. First and foremost, I would like to extend my heartfelt appreciation to all of the members for entrusting me with this responsibility.

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I believe the progress and development of CTRMS are essential to the advancement of medical science. From blood transfusions to pancreatic islet transplantation, hepatocyte transplantation, and regenerative medicine, Cell Transplantation has always played a vital role in the advancement of medicine. It will almost definitely do so in the future.

As the name suggests, our CTRMS will cover all areas related to cell transplantation. We are quite fortunate about this since there is so much to be gained from the studies in areas that are comparable to our expertise but not our specialization. And it is evident that collaborating with outstanding scholars outside your field is far more advantageous than competing in a confined field.

How can an academic organization like our CTRMS contribute to society? It all comes down to making connections. We connect with each other, communicate, exchange new findings, and learn novel technologies on the platform, named CTRMS.

I envision extending our connection to different regions around the globe to advance our organization globally by empowering diversity.

I also envision involving the younger generation by boosting activities. We've all admired the camaraderie of our mentors' generation, and their ability to gather and create memorable experiences with prominent figures from around the world. I aim to offer the next generation similar opportunities and help them create memories with their peers. This desire to connect, to become part of a community, is what drives our organization to expand, foster collaboration, and contribute to science.

At its core, it's about building connections. I hope that two years from now, we can meet in Tokyo and provide a gathering that spans both horizons and generations.

To make this happen, I humbly request your cooperation. Please continue to lend your unwavering support to further the development of CTRMS.

Thank you,

Dr. Toshio Miki
CTRMS President 2023-2025
Nihon University, Japan

Recent Award Winners

IPITA-IXA-CTRMS 2023 Congress Recordings are now available

Many thanks to the over 600 attendees from 30 countries who attended and supported the 2023 Joint Congress of the IPITA, IXA and CTRMS in San Diego, California on October 26-29, 2023.

Past Webinars and Recordings

The Transplant Infectious Disease Section (TID) has prepared a new update and guidance on the 2019 Novel Coronavirus (2019-nCov) for transplant ID clinicians.



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