Injectable Hydrogel Aims to Keep Osteoarthritis Drugs in Joints for Weeks

Scientists at the University at Buffalo have developed an injectable hydrogel designed to keep osteoarthritis medication inside a joint for several weeks after a single minimally invasive injection. The material also acts as a lubricant, combining sustained drug delivery with a function similar to a viscosupplement.

The formulation is injected as a liquid. At body temperature, it rapidly changes into a smooth, semisolid depot that remains in the joint while releasing drug-loaded nanocarriers over time. According to the Research Foundation for the State University of New York, the system is intended to address the rapid clearance of small-molecule drugs and biologics from synovial fluid, the liquid surrounding the joint.

The platform combines a biocompatible polymer matrix with nanocarriers capable of holding relatively high amounts of hydrophobic, or poorly water-soluble, therapeutic compounds. Once the depot forms, medication is released through diffusion and the gradual relaxation of the hydrogel matrix. The researchers also used materials with prior regulatory acceptance, which they said could make eventual clinical translation more practical. That feature does not establish that the hydrogel itself has received regulatory authorization.

Researchers validated the delivery approach using a SIRT6 activator and reported that the platform could be adapted for other hydrophobic disease-modifying compounds. The source describes potential targets including biological processes linked to osteoarthritis, such as chronic inflammation and cellular senescence. It does not provide details on the study model, sample size, drug quantity, duration of testing, or measured therapeutic outcomes.

Existing injections used directly in joints, including analgesics, corticosteroids, and viscosupplements, can provide symptom relief, but the source says their effects are often short-lived and that they do not consistently slow osteoarthritis progression. The new hydrogel is intended to maintain a more concentrated local exposure while potentially limiting exposure elsewhere in the body. Researchers say that could reduce the frequency of invasive injections and the possibility of systemic side effects, although those benefits remain potential applications rather than established clinical results.

The primary intended use is knee osteoarthritis. The same delivery concept may also be relevant to post-traumatic osteoarthritis, intervertebral disc degeneration, rotator cuff degeneration, and other localized applications involving hydrophobic drug candidates. The report presents the work as a drug-delivery platform under development; it does not establish that the injection treats osteoarthritis in humans, slows disease progression, improves pain, or is available for patient use.