One injection could keep osteoarthritis drugs working for weeks

After a single minimally invasive injection, the material changes from a liquid into a smooth, lubricating semisolid depot at body temperature. Once in place, it can remain in the joint for several weeks while gradually releasing drug-loaded nanocarriers.

A Major Challenge in Osteoarthritis Treatment

Osteoarthritis (OA) is one of the world's leading causes of chronic pain and disability. Common treatments delivered directly into joints, including analgesics, corticosteroids, and viscosupplements, can ease symptoms, but their effects are often short-lived, and they do not consistently slow the progression of the disease.

One of the biggest obstacles is that small molecule drugs and biologics can be cleared quickly from synovial fluid. Researchers also face challenges when trying to deliver hydrophobic drugs at concentrations high enough to be effective without increasing exposure throughout the rest of the body.

The University at Buffalo hydrogel platform was designed to address both problems by keeping therapeutic compounds concentrated in the joint and releasing them gradually over time.

A Drug Depot That Forms Inside the Joint

The injectable formulation begins as a liquid, allowing it to be delivered with a minimally invasive procedure. At body temperature, it rapidly becomes a lubricious semisolid material that acts as a local drug reservoir.

The platform combines a biocompatible polymer matrix with drug-loaded nanocarriers. These nanocarriers are designed to carry high amounts of poorly soluble therapeutic compounds, which are otherwise difficult to deliver in an aqueous environment.

The system also uses materials with prior regulatory acceptance, a feature intended to make eventual clinical translation more practical.

Once inside the joint, therapeutic compounds are released through diffusion and gradual relaxation of the hydrogel matrix. This process provides controlled local exposure over multiple weeks rather than allowing the medication to disappear rapidly from the joint.

Researchers have validated the approach using a SIRT6 activator. The platform can also be adapted to carry other hydrophobic disease-modifying compounds.

Longer Lasting Drug Delivery and Joint Lubrication

One potential advantage is a longer therapeutic window. By retaining medication locally for an extended period, the system could reduce how often patients need invasive joint injections while also lowering the possibility of systemic side effects.

The hydrogel was also designed with disease modification in mind. Rather than focusing only on pain relief, it could deliver compounds that target biological processes involved in osteoarthritis, including chronic inflammation and cellular senescence.

Another feature is its dual role inside the joint. The material functions both as a sustained-release drug delivery system and as a viscosupplement, meaning it could potentially improve joint lubrication while simultaneously delivering treatments aimed at the underlying disease.

The platform can carry poorly soluble drugs at relatively high concentrations and can be adapted for different therapeutic payloads and joint applications.

Potential Uses Beyond Knee Osteoarthritis

The primary intended application is knee osteoarthritis (large addressable market).

The same technology could also have potential uses in post-traumatic OA, intervertebral disc degeneration, rotator cuff degeneration, and the localized delivery of other hydrophobic drug candidates.