By Jingduan Yang
Patients paralyzed due to spinal cord injuries may one day achieve complete recovery following stem cell and exosome therapy. Even though these treatments are not yet approved by the U.S. Food and Drug Administration (FDA), clinical cases and research have shown that these two novel regenerative medicine treatments offer new hope to those suffering from previously incurable conditions such as traumatic paralysis.
Stem cells have the unique ability to self-renew and differentiate into various cell types. Stem cell therapy can regenerate and repair tissues damaged or affected by disease by directing stem cells to develop into specific types of cells.
Exosomes are membrane-bound extracellular vesicles released from cells, with diameters ranging from approximately 40 to 160 nanometers. These vesicles accumulate specific cellular components, such as nucleic acids, proteins, lipids, and metabolites, which possess functional, targeted, and mechanistic properties, playing a role in modulating intercellular communication.
Stem cell-derived exosome therapy retains the therapeutic benefits of stem cells while eliminating the need for donor cells. Additionally, exosomes contain nearly three times the growth factors found in adult stem cells, which enhances their capacity to restore and rejuvenate target cells. This therapy is promising for treating conditions such as osteoarthritis, chronic pain, and musculoskeletal injuries.
How do stem cells and exosomes function in disease treatment? Let’s explore this through a specific case study.
A Case Study
The patient was a 35-year-old man who sustained severe spinal cord injuries in a car accident, resulting in paralysis of his lower body. Although doctors informed him that such damage is difficult to fully recover from, he remained hopeful. On the recommendation of friends, he sought treatment at a renowned regenerative medicine center, hoping to regain his health through the latest therapeutic approaches.
At the center, doctors conducted a comprehensive assessment of his spinal cord injury. As part of a clinical trial, the treatment team employed a combined approach of stem cell and exosome therapy—a novel treatment designed to enhance spinal cord regeneration and repair.
After several months of stem cell and exosome therapy, remarkable changes occurred. The patient first regained sensation in his legs—he was able to feel light touches and temperature changes—which thrilled him. Additionally, his motor function gradually improved, and he began to regain strength in his legs, allowing him to walk with assistance.
This improvement continued over several months of ongoing treatment—previously unimaginable—as spinal cord injuries leading to paralysis are generally considered difficult to reverse, especially in traumatic cases. After over a year of treatment, he not only regained the ability to walk independently but was also able to perform some light exercises, significantly improving his quality of life. This demonstrates the crucial role that the combination of stem cells and exosomes plays in the regeneration of cells and tissues.
Stem Cell and Exosome Therapies
Stem cells are a type of cell in our body that can differentiate into various tissues and organs, and possess significant restorative capabilities. They function as versatile repair agents, capable of transforming into different cell types, including nerve cells, to facilitate the repair of spinal cord tissue.
A study conducted by the Mayo Clinic and published in Nature Communications in April involved administering mesenchymal stem cell therapy to 10 patients with traumatic spinal cord injuries. The results indicated that the implementation of the treatment was successful and safe for all patients, with seven of them showing improvement in the severity of their spinal cord injuries.
Stem cells can be extracted from different sources, including bone marrow, amniotic cells, adipose tissue, umbilical cord, and placental tissue. Due to their immunological properties, stem cells generally must be sourced from the patient’s body.
These cells are primarily harvested from bone marrow and then cultured for a period to sufficiently increase their numbers. Once prepared, they are transplanted into the injured area of the patient’s spinal cord, where they function to repair and regenerate damaged nerve tissue.
Stem cells exhibit pleotropic therapeutic potential through mechanisms such as inhibiting inflammation or apoptosis (normal cellular death), recruiting cells, stimulating angiogenesis (development of new blood vessels), and promoting differentiation.
On the other hand, exosomes are vesicles secreted by cells as they perform their functions within the body. These vesicles do not carry the DNA of the originating cell but contain various types of information.
When an exosome derived from a stem cell fuses with another cell, it can mimic the functions of the stem cell. In other words, exosomes function like couriers, delivering repair materials and signals to other cells, particularly other stem cells, thereby enhancing their function.
Exosomes are extracted from stem cells, cultured, and then injected into the area surrounding the patient’s spinal cord. These exosomes carry essential repair signals that stimulate active healing in damaged tissues. Combining stem cells with exosomes improves the overall effectiveness of the treatment.
Stem Cell Therapy vs. Exosome Therapy
Stem cell therapy is highly effective in repairing damaged tissues and organs, such as in heart repair after a heart attack, spinal cord or nerve repair, and bone marrow transplants for leukemia and lymphoma. Its advantages include versatility, high plasticity, and long-term repair capabilities.
However, it has three major drawbacks:
1. Immune rejection: Stem cells from another person cannot be used due to the risk of immune rejection.
2. Tumor formation: Undifferentiated stem cells carry the risk of tumor formation.
3. High cost: The production, cultivation, and transplantation of stem cells are expensive.
Compared to stem cell therapy, exosome therapy offers several advantages. First, exosomes lack immunological properties and do not trigger immune rejection, allowing exosomes from healthy donors to be used for treatment.
Additionally, exosomes have potent immune-regulating functions that can reduce inflammation and promote tissue repair. While their tissue repair capabilities may not be as significant as those of stem cells, exosomes still provide substantial benefits and exhibit strong anti-inflammatory effects.
Furthermore, exosome therapy can be administered in various forms—through injection, inhalation, or intravenous infusion—making it a safer and more versatile option.
The main challenges of exosome therapy include rigorous production and purification requirements, which affect both efficiency and cost. Additionally, standardization issues further constrain its clinical translation and application.
Availability
Currently, those seeking exosome therapy will have to wait as it is in the clinical trial stage and not yet FDA-approved.
As for stem cell therapy, the only FDA-approved stem cell products available at this time are hematopoietic progenitor cells (blood-forming stem cells) derived from umbilical cord blood. These cells are specifically approved for patients with hematologic diseases affecting blood production but are not approved for other uses.
When considering stem cell therapy, concerns typically involve issues of immune rejection and tumor growth as well as high costs. Similarly, exosome therapy also entails significant expenses. These factors represent some of the key challenges currently facing regenerative medicine.
In summary, regenerative medicine enhances the body’s natural self-repair mechanisms and offers significant benefits for patients with critical needs. The advancement of regenerative medicine provides renewed hope for many patients. As technology continues to progress, stem cell and exosome therapies are expected to play an increasingly significant role in addressing a broader array of diseases.
