An experimental treatment uses specialized neurons derived from stem cells to “soak up” triggers of pain and inflammation in the arthritic knees of mice.
This lab-mouse experiment suggests the therapy could possibly help with chronic pain in people, caused by conditions like osteoarthritis, for example. the hope is that the “pain sponge” could enable patients to stop relying on opioid medications for pain relief, the researchers say.
And as a bonus side effect, the engineered neurons also promoted bone and cartilage repair in the mice they were tested in, the researchers reported in a preprint posted to the server bioRxiv in December 2025. The work has not yet been peer-reviewed.
“The possibility that the therapy could both relieve pain and slow cartilage degeneration is especially compelling for osteoarthritis,” Chuan-Ju Liu, an orthopedics professor at yale University who wasn’t involved in the study, told Live Science.
How the pain sponge works
The therapy, known as SN101, uses human using hPSCs to replace or repair damaged neurons, SN101 doesn’t aim to replace pain-sensing neurons.Instead, the hPSC-derived neurons are injected at the site of inflammation and work alongside existing neurons.
These new neurons act as decoys, binding to inflammatory factors and preventing them from activating the body’s original pain receptors.
Potential pros of SN101
Chronic pain, lasting three months or longer, is frequently treated with opioid drugs. Opioids reduce pain by binding to receptors in the body, but they also cause side effects like nausea and carry a risk of addiction.
Despite these risks, approximately 20% of adults experiance chronic pain, and over half of those individuals use opioid medications, according to data published in Arthritis & Rheumatology.
SN101 offers a potential option.by intercepting inflammatory signals, the drug could reduce pain without the drawbacks associated with opioids. Early trial results, presented at the 2024 Society for Neuroscience conference, showed SN101 reduced pain scores in patients with chronic lower back pain.
Researchers are now conducting Phase 3 clinical trials to further evaluate SN101’s safety and effectiveness. Results are expected in late 2025 or early 2026.
