Stem Cell Therapy (MSCs) — Mesenchymal Stem Cells — Regenerative Therapies
Cell-based regenerative therapy using mesenchymal stem cells. FDA regulates as biological product. Emerging evidence for joint and tissue repair.
Overview
Mesenchymal stem cell (MSC) therapy involves the isolation and injection of multipotent stromal cells derived from bone marrow, adipose tissue, or umbilical cord tissue for tissue repair and regeneration. MSCs can differentiate into osteoblasts, chondrocytes, and adipocytes, and they secrete a broad array of paracrine factors (growth factors, cytokines, exosomes) that modulate inflammation, promote tissue repair, and recruit endogenous regenerative cells. In orthopedic medicine, MSC therapy has been most studied for knee osteoarthritis and focal cartilage defects, with systematic reviews showing moderate improvement in pain and function scores at 12-24 months. However, the evidence base is limited by small sample sizes, lack of blinding, and heterogeneity in cell source, preparation, dose, and delivery method. The FDA regulates stem cell products as biological drugs under Section 351 of the Public Health Service Act if they are 'more than minimally manipulated' or used in a non-homologous manner. This means that culture-expanded MSCs, allogeneic (donor) cells, and cells used outside their normal tissue context require IND/BLA approval. However, autologous 'same surgical procedure' use of minimally manipulated cells (e.g., bone marrow concentrate, SVF from liposuction) falls under a regulatory exception. The FDA has taken enforcement action against clinics offering unapproved stem cell treatments, and has warned consumers about safety risks including infections, tumor formation, and migration of cells to inappropriate locations.
Indications
- Investigational: Knee osteoarthritis (numerous clinical trials)
- Investigational: Cartilage repair and regeneration
- Investigational: Spinal disc degeneration
- Investigational: Autoimmune conditions (GvHD, Crohn's)
- FDA-approved: Bone marrow transplant for hematologic conditions (different application)
Mechanism of Action
MSCs secrete growth factors (TGF-beta, IGF-1, HGF, VEGF), cytokines, and exosomes that modulate the local tissue environment toward repair
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Bone marrow concentrate (BMC) | 5-10 mL (variable cell count) | Single injection or 2 injections 4-6 weeks apart | Autologous, same-day procedure; minimally manipulated |
| Culture-expanded MSCs | 10-100 million cells | Single injection | Requires IND approval; higher cell counts but regulatory hurdle |
Evidence Grade
GRADE C
Safety & Contraindications
- FDA regulates most MSC products as biological drugs — many clinic offerings are unapproved
- Infection risk from injection procedures
- Theoretical tumorigenicity with culture-expanded cells
- Cell migration to unintended sites possible
- Immune reactions with allogeneic (donor) cells
- Highly variable quality and cell counts between preparations
- Very expensive ($3,000-$25,000+) with no insurance coverage
- FDA enforcement actions against unapproved clinics