What You Need To Know About Stem Cells And Healing | Dr. Mari Mitrani
My patients ask me about stem cells constantly, and I will be honest about where that leaves me.
I trained at Columbia. I did my residency at a program that takes orthopedic education seriously. And I received exactly zero training on stem cells, exosomes, or any regenerative therapy beyond PRP, which itself was barely touched. Fifteen years into practice, I am learning alongside my patients, doing my own reading, taking my own courses, because the questions coming into my clinic are not slowing down. They are accelerating. And most of the time, what patients are holding is a term they found online, a hope attached to it, and almost no framework for understanding what they are actually asking about.
Dr. Mari Mitrani is the person I wanted in the room for that conversation.
Mari is an MD, PhD, physician scientist, and regenerative medicine innovator who has spent more than twenty years in a field she describes, without exaggeration, as one she helped create. She has served as Chief Science Officer steering FDA approved trials for exosome therapeutics, invented patents in the exosome space, secured five IND approvals with the FDA, and built laboratories that manufactured stem cells and exosomes from the ground up. She is currently shaping the future of reproductive genetics at Gattaca Genomics. We met through Pinnacle, became friends, and I have been waiting to get her in front of a microphone ever since.
This conversation is for every patient who has come in asking about stem cells and every physician who has not known quite what to tell them.
A Clinic in Ecuador and a Career That Pivoted
Mari did not plan to spend her career in regenerative medicine. She trained as an MD, PhD in Ecuador with every intention of becoming an OB GYN. What redirected her was a project that arrived before the field had a name.
In 2008, she joined forces with a hematologist colleague of her father's, a physician who had spent decades using stem cells in bone marrow transplants for blood cancers and asked a question that sounds simple in retrospect: if we use these cells for donor treatments, why not for the patient's own healing? That question became a small clinic in Ecuador, drawing patients from the US and Canada who had exhausted other options. The protocol was genuinely ahead of its time: IV vitamins, neural therapy, nutrition, lymphatic detox, and mental preparation before patients ever received the stem cell treatment itself. Mind and body were considered inseparable from the start.
The results in those first rotations of eight to ten patients were unexpected enough that Mari shelved her OB GYN plans entirely. She watched paraplegics and quadriplegics respond in ways the team did not fully understand yet. Within two years a small clinic had to become a much larger installation. They moved from bone marrow punctures to an apheresis device, the same kind of machine used to collect stem cells for blood cancer patients, which pulls a third of the patient's blood volume through an external circuit, separates the stem cells by weight, and returns everything else to the body. The stem cells collected at the end are the patient's own, activated by the mechanical stress of the process itself, and reinfused intravenously.
After one local television interview, Mari told me, the line outside stretched two city blocks.
What Stem Cells Actually Do
Here is where I want to slow down, because this is where most of the public confusion lives, and Mari was precise about it in a way I found genuinely clarifying.
Stem cells are not building new tissue. They are not implanting themselves into your knee and regenerating cartilage from scratch. That is the popular mental image, and it is wrong. What stem cells are is undifferentiated, blank cells that respond to signals in their environment. When they encounter inflammation or injury, they communicate with the existing cells in that area, the ones that are supposed to be doing repair work but have, through age or injury or oxidative stress, essentially forgotten their job. The stem cells arrive, Mari said, like generals. They ask why the repair has stopped. They reignite the process. It is your own immune system that then receives that message and executes the healing.
The mechanism runs through exosomes, which is where the science has moved in the past decade. Every cell in the body produces exosomes constantly. They are tiny lipid bubbles carrying microRNA, messenger RNA, enzymes, and proteins, essentially molecular emails between cells, specific messages about what is needed and where. For a long time researchers dismissed these secretions as cellular waste. Better technology revealed that they are the primary language cells use to communicate. And when scientists began rerunning their stem cell experiments using exosomes alone, the results came back remarkably similar. The message, it turns out, is doing most of the work.
The practical difference matters. Stem cells are whole cells requiring careful freezing with specialized compounds, and roughly thirty percent do not survive the thaw. Exosomes are lipid bubbles stable at standard freezer temperatures, easier to manufacture consistently, and easier to characterize. Neither is universally better than the other. Mari's analogy was direct: you are still talking about cars. A Tesla, a Maserati, a Fiat, a motorcycle. Different vehicles for different purposes, and the question is always what you actually need.
From COPD to Covid to Osteoarthritis in Three Years
Mari's path from that clinic in Ecuador to FDA approvals ran through a pivot she did not anticipate. Her team had spent years building a case for a COPD trial, working with the University of Miami's neonatal department on a lung injury model in premature infants, accumulating roughly two hundred pages of data. They were ready to present it when covid arrived and the FDA opened an emergency pathway for any serious therapeutic candidate with existing data.
Her team pivoted in days. They became the first company to receive an IND approval for a covid therapeutic using stem cell and exosome based treatment, doing it in thirty days. From there they treated severe ICU cases, then early intervention cases, then long haulers. When that phase wound down, they turned back to orthopedics, securing an osteoarthritis of the knee trial and eventually the COPD trial they had been building toward all along. All of it happened within three years, with a team she described as ten mighty soldiers.
I asked her what drove that pace and she was straightforward about it. She had watched patients with COPD who were receiving orthopedic pain injections start getting off supplemental oxygen as a side effect. Not one patient. Not two. Enough that the team could not dismiss it. When you see something you cannot explain, she said, you go after it. The sky is the limit when you are determined and you act correctly.
What Patients Should Actually Ask
The availability question is the one my patients want answered, and Mari did not soften it. The honest reality is that products are being manufactured, sold, and used without official approval in most states. Florida passed a law in July 2025 permitting licensed physicians to administer these treatments legally for orthopedic pain and wound healing, and she expects other states to follow. But the regulatory landscape is still catching up to the clinical reality, which means the burden of vetting falls on patients and physicians.
The questions she recommends asking are specific. Who is the donor and how were they qualified? Was a medical professional involved in reviewing the donor's chart? How was the tissue collected, and was it done in a proper operating room setting? Does the manufacturer have a certificate of analysis? What sterility and endotoxin testing was performed? How many cells or exosomes are in the product, and have they been characterized? These are not unreasonable questions. A legitimate manufacturer will answer them. One that cannot or will not is telling you something important.
On cord blood banking, which comes up constantly in my clinic, Mari was clear: the stem cell content of cord blood is actually quite low. The cells collected are regenerative but are not technically stem cells in the way the term is now understood. She is not dismissive of it, but she wants patients to understand that what they have stored is not equivalent to what is being used in placental or perinatal derived therapies. The donor tissue in those treatments comes from placenta, a uniquely immunoprivileged material that carries neither the mother's identity nor the baby's, only a general human identity that the body does not attack. That property, she said, is what makes it the most promising raw material in regenerative medicine. FDA has clear rules about how it is collected, always in an operating room, always with the mother's consent, always with full donor traceability.
Education is the thread running through everything Mari does and everything she sees going wrong in this field. Marketing has outpaced science in the public conversation about regenerative medicine, and patients are arriving with terminology they have absorbed without the framework to evaluate it. She is building toward that as her next project, and I will be at the front of the line for whatever she produces.
We will be doing a part two. There is too much ground left to cover.
Connect
You can find Dr. Mari Mitrani @marimitrani on social media. For more conversations like this one, subscribe to The Resilience Factor wherever you get your podcasts, and find me @dr.pamelamehta on social media.
