Osteoporosis often advances silently, gradually weakening bones until a severe fracture reveals the damage.
This disease primarily affects older people, especially women, and is responsible for millions of fractures around the world each year.
Current drug treatments generally take months to begin working and act on the entire skeleton rather than targeting specific problem areas. Now, a French startup called Flowbone has introduced an injectable hydrogel that promises to strengthen targeted bones quickly, offering patients a faster and more precise treatment than traditional therapies.
Limitations of Current Osteoporosis Treatments
For decades, osteoporosis has been managed with systemic drugs that either encourage bone growth or slow bone loss. Although these treatments can be effective, they often take as long as a year to produce significant improvements in bone density. That delay poses serious risks for older adults who may fall and fracture fragile bones. Dominique Pioletti, head of the Laboratory of Biomechanical Orthopedics at EPFL, noted, “In the absence of effective preventive measures, around 40% of women over age 50 will suffer at least one major osteoporotic fracture; in men, the percentage is about 20%.” These fractures can be life-threatening, with a 20% mortality rate in the year following hip or femoral neck fractures.
A New Injectable Hydrogel Solution
To address this need for a faster treatment, EPFL researchers have created an injectable hydrogel containing hyaluronic acid and hydroxyapatite nanoparticles. Once injected into weakened bone, the hydrogel acts as a scaffold to support new bone growth and improve density. Preclinical trials in mice showed impressive results, with bone density increasing two to three times within just two weeks. Another advantage is its biocompatibility: the hydrogel integrates naturally with bone tissue, without causing inflammation or rejection.
Combining Hydrogel with Existing Medications
Researchers also discovered that combining this hydrogel with traditional osteoporosis drugs significantly improved its effectiveness. In trials, they tested adding parathyroid hormone, as well as directly loading the hydrogel with the anti-resorptive drug zoledronate. These combinations produced a dramatic 4.8-fold increase in bone density at the injection site within a few weeks. According to Pioletti, “Our findings suggest that injectable hydrogels delivering local anti-catabolic drugs can complement systemic anabolic therapy by rapidly boosting local bone density.” This approach could offer much-needed, immediate reinforcement for high-risk patients.
How the Hydrogel Works
The hydrogel’s success lies in its advanced biomimetic design. Hyaluronic acid creates a soft, water-attracting scaffold that mimics bone’s natural environment, helping cells move in and start regenerating tissue. Hydroxyapatite particles simulate the structural properties of bone and send chemical signals that stimulate bone-building cells. Unlike existing bone cements, which are hard and brittle, this hydrogel is flexible and injectable, allowing it to fill irregular and complex spaces. Studies also suggest that similar hydrogels could be adapted for cartilage repair and other orthopedic uses.
What Comes Next
So far, the new hydrogel has only been tested in animal models. The next step is to begin human clinical trials, with the hope of helping people at high risk of fractures or those needing stronger bones to support implants like dental anchors or artificial hips. One of Flowbone’s scientists, Régis Gauderon, acknowledged, “The road to getting our product approved and into the clinic is still very long.
Fortunately, our motivation is strong and infallible!” If successful, these hydrogels could soon deliver targeted, rapid treatment within days or weeks rather than months or years.
