Scientists at the University at Buffalo have developed an injectable hydrogel designed to keep osteoarthritis treatments inside the joint much longer than conventional injections.
After a single minimally invasive injection, the material changes from a liquid to a mild lubricating semi-solid reservoir at body temperature. Once in place, it can remain in the joint for several weeks while gradually releasing drug-loaded nanocarriers.
A great challenge in the treatment of osteoarthritis
Osteoarthritis (OA) is one of the leading causes of chronic pain and disability in the world. Common treatments administered directly to the joints, including pain relievers, corticosteroids, and viscosupplements, can relieve symptoms, but their effects are usually short-lived and do not consistently slow disease progression.
One of the biggest obstacles is that small molecule drugs and biologics can be rapidly eliminated from the synovial fluid. Researchers also face challenges when trying to administer hydrophobic drugs at concentrations high enough to be effective without increasing exposure to the rest of the body.
The University at Buffalo hydrogel platform was designed to address both problems by keeping the therapeutic compounds concentrated in the joint and gradually releasing them over time.
A drug reservoir that forms inside the joint
The injectable formulation begins as a liquid, allowing it to be administered through a minimally invasive procedure. At body temperature, it quickly converts into a semisolid lubricating material that acts as a local drug reservoir.
The platform combines a biocompatible polymeric matrix with drug-loaded nanocarriers. These nanocarriers are designed to transport large quantities of poorly soluble therapeutic compounds, which would otherwise be 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, the therapeutic compounds are released through diffusion and gradual relaxation of the hydrogel matrix. This process provides controlled local exposure over several weeks rather than allowing the medication to rapidly disappear from the joint.
The researchers have validated the approach using a SIRT6 activator. The platform can also be adapted to transport other disease-modifying hydrophobic compounds.
Longer lasting joint lubrication and medication delivery
A potential advantage is a longer therapeutic window. By retaining medication locally for an extended period, the system could reduce the frequency with which patients need invasive joint injections while reducing the potential for systemic side effects.
The hydrogel was also designed with disease modification in mind. Instead of focusing solely on pain relief, it could deliver compounds that target biological processes implicated in osteoarthritis, including chronic inflammation and cellular senescence.
Another characteristic is its double function within the joint. The material functions as a sustained-release drug delivery system and as a viscosupplement, meaning it could potentially improve joint lubrication while delivering targeted treatments to the underlying disease.
The platform can transport poorly soluble drugs at relatively high concentrations and can adapt to different therapeutic payloads and co-applications.
Potential uses beyond knee osteoarthritis
The main intended application is knee osteoarthritis (large target market).
The same technology could also have potential uses in post-traumatic OA, intervertebral disc degeneration, rotator cuff degeneration, and localized delivery of other hydrophobic drug candidates.