Key Biscayne and Muse Cells: What the Published Studies Show
Medically reviewed by Dr. Charles Pereyra, MD — Medical Director, Springs Rejuvenation. Last reviewed October 15, 2026.
Written by the Springs Rejuvenation regenerative medicine team from direct clinical experience administering stem cell and exosome protocols at our Aventura, Miami center.
Key Biscayne residents exploring regenerative medicine options increasingly encounter references to Muse cells—multilineage-differentiating stress-enduring cells—a distinct category of stem cell first characterized by Japanese researchers in 2010. Unlike embryonic or induced pluripotent stem cells, Muse cells are found in adult bone marrow and other tissues, identifiable by the SSEA-3 surface marker, and exhibit stress-tolerance and pluripotent-like differentiation capacity. Understanding what the published peer-reviewed literature actually shows—and what remains investigational—helps patients approach this emerging field with informed expectations rather than assumptions.
Muse cell therapy is not FDA-approved and remains investigational in the United States. The evidence base consists primarily of preclinical models, early-phase safety studies, and a small number of randomized human trials conducted in Japan. Individual responses vary, and not every published study has demonstrated positive outcomes. This article walks through the key publications, explains the proposed biological mechanisms, and outlines the questions a candidate should ask before pursuing muse cell therapy Key Biscayne or anywhere else.
What Makes Muse Cells Distinct From Other Stem Cell Approaches
Kuroda, Dezawa and colleagues first isolated Muse cells from human bone marrow in 2010, publishing their findings in the Proceedings of the National Academy of Sciences. These cells constitute roughly 1-3% of the mesenchymal stromal cell population and can be identified by the stage-specific embryonic antigen-3 (SSEA-3) marker. The defining characteristic is their ability to differentiate into cells from all three embryonic germ layers—ectodermal, mesodermal, and endodermal lineages—when placed under appropriate induction conditions in laboratory culture. They also survive under stress conditions that eliminate most other cell types, hence the name "stress-enduring."
Wakao, Dezawa and colleagues extended this work in 2011, demonstrating that Muse cells can be collected not only from bone marrow but also from adipose tissue and circulating blood. When delivered intravenously in preclinical models, Muse cells appeared to migrate preferentially to sites of tissue damage rather than distributing randomly throughout the body—a phenomenon that would, if confirmed in humans, offer an advantage over some earlier cell therapies that required direct injection into the damaged organ.
The Homing Mechanism: How Delivered Cells May Find Their Target
Yamada and colleagues published a landmark paper in Circulation Research in 2018 that examined the biological signals governing Muse cell homing. The research team identified the sphingosine-1-phosphate receptor 2 (S1PR2) pathway as a critical chemotactic axis. Damaged tissues release sphingosine-1-phosphate (S1P), a lipid signaling molecule, which binds to S1PR2 receptors on the surface of intravenously delivered Muse cells and guides them toward the injury site. In animal models, blocking this receptor abolished the homing effect, while Muse cells expressing S1PR2 accumulated in damaged tissue within hours of intravenous infusion.
This proposed mechanism differs from earlier mesenchymal stem cell therapies, many of which relied on local injection to ensure cells reached the target. The S1P–S1PR2 gradient offers a theoretical basis for systemic, intravenous delivery. However, these findings come from controlled laboratory and animal studies. Human tissue environments are more complex, and the degree to which this homing occurs in real-world clinical settings remains an active area of investigation.
Early Human Safety Studies and Randomized Trials
Noda and colleagues reported the first-in-human safety study in 2020, published in the Circulation Journal. This Phase I trial evaluated intravenous infusions of allogeneic Muse cells (product name CL2020) in a small cohort of patients. The primary endpoint was safety—assessing adverse events, immune reactions, and tolerability—rather than efficacy. The investigators found no serious adverse events attributable to the cell infusion over the follow-up period, which provided preliminary evidence that intravenous Muse cell delivery could be conducted without immediate safety concerns in a controlled hospital setting.
Niizuma and colleagues published a randomized, double-blind, placebo-controlled trial of CL2020 in Neurology in 2023. This study enrolled patients in Japan and assessed both safety and exploratory efficacy measures. The trial met its primary safety endpoint, confirming the earlier findings from Noda's work. However, the efficacy results were modest, and the authors noted that individual responses varied. Not every participant experienced measurable improvement, and the effect sizes were smaller than some earlier preclinical models had suggested. This outcome underscores a recurring theme in regenerative medicine: laboratory success does not always translate directly to clinical benefit, and realistic expectations matter.
Hare and colleagues conducted an intravenous MSC safety trial published in the Journal of the American College of Cardiology in 2009. Though this study used mesenchymal stromal cells rather than Muse-specific cells, it established that allogeneic, intravenously delivered cells could be administered safely in a clinical setting. Similarly, Bartolucci and colleagues reported in 2017 (Circulation Research) on a trial examining umbilical-cord-derived MSCs, which demonstrated modest functional improvements in some participants but also highlighted the variability of response. These studies collectively inform the safety profile and realistic outcome range for intravenous regenerative cell therapies, Muse cells included.
Muse Cell Therapy Key Biscayne: What Candidates Considering This Approach Should Understand
For Key Biscayne residents weighing muse cell therapy, the most important takeaway is that this field remains investigational. Physician-supervised Muse cell therapy is available at select centers in the United States, including the Springs Rejuvenation clinic in Miami, which means patients no longer need to travel overseas to access these protocols. Dr. Charles Pereyra, MD, the medical director, conducts individualized screening to assess candidacy, review the published evidence with each patient, and explain the limitations candidly.
Not every patient is a suitable candidate. Screening typically includes a review of medical history, current medications, prior therapies, and realistic goals. Dr. Pereyra emphasizes that the existing human data—while promising in terms of safety—demonstrates that individual responses vary and outcomes are not certain. The literature shows variability, and some individuals in published trials experienced minimal or no measurable benefit. Informed consent requires understanding both the potential and the uncertainty.
Questions Every Candidate Should Ask Before Moving Forward
An informed approach to any investigational therapy begins with questions. Candidates considering muse cell therapy Key Biscayne or elsewhere should ask their physician: What is the source of the cells? Are they allogeneic (donor-derived) or autologous (from the patient's own tissue)? What processing and quality-control steps ensure cell viability and purity? How many cells will be delivered, and by what route—intravenous infusion, local injection, or both?
Patients should also inquire about follow-up. What monitoring will occur after the infusion? What symptoms should be reported immediately? What timeline is reasonable for assessing whether any response has occurred? Because the peer-reviewed trials used defined protocols with scheduled imaging and functional assessments, replicating that structure in a clinical setting offers the best chance of detecting real changes and distinguishing them from placebo effects or natural fluctuation.
Finally, cost and insurance coverage warrant direct discussion. Investigational therapies are rarely covered by insurance, and out-of-pocket expenses can be substantial. Understanding the financial commitment upfront, along with any refund policies or stated outcome expectations (or absence thereof), prevents misunderstanding later.
Are Muse cells the same as embryonic stem cells?
No. Muse cells are found in adult tissues such as bone marrow and adipose tissue and are identified by the SSEA-3 marker. Embryonic stem cells are derived from early-stage embryos. While both exhibit pluripotent-like capacity in laboratory settings, Muse cells avoid the ethical and regulatory concerns associated with embryonic sources and do not require genetic reprogramming.
How long does it take to see results from Muse cell therapy?
The published human trials followed participants for weeks to months, with imaging and functional assessments conducted at defined intervals. Early changes, if they occur, may appear within the first few weeks, but maximal effects—when observed—often develop over two to three months. Individual timelines vary, and some participants in published studies did not experience measurable improvement at any timepoint.
Is Muse cell therapy FDA-approved?
No. Muse cell infusions remain investigational in the United States and have not received FDA approval. The CL2020 product has been studied in clinical trials in Japan, but those trials do not confer regulatory approval in the US. Patients pursuing this approach do so under physician discretion in a clinical research or off-label context, with informed consent acknowledging the investigational status.
What are the known risks of intravenous Muse cell delivery?
The early-phase trials by Noda and Niizuma reported no serious adverse events directly attributable to the cell infusion. Theoretical risks include immune reactions, infusion-related fever or chills, and embolism if cells clump. Rigorous quality control, physician supervision, and post-infusion monitoring mitigate these risks. Long-term safety data beyond one year remain limited, so extended follow-up is prudent.
At Springs Rejuvenation, stem cell and exosome therapies are used together as part of a personalized regenerative protocol.
Medical Disclaimer: Stem cell and exosome therapy is not an FDA approved therapy and is considered to be in the experimental stages. These statements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Springs Rejuvenation processes exosomes in an FDA approved lab. Individual results may vary. This content is reviewed for medical accuracy by Dr. Charles Pereyra, MD, Medical Director of Springs Rejuvenation, and is provided for educational purposes only. Always consult a qualified physician.