An innovative gel developed by scientists at the Swiss Federal Institute of Technology Lausanne (EPFL) is set to revolutionize methods for treating bone weakness and fractures. This gel strengthens bone and offers a new approach to combating osteoporosis, a condition known to weaken bones and increase fracture risk in patients. The research, published in the journal Bone, was led by Vincent Stadelmann and Dominique Pioletti. Study results showed that the hydrogel significantly and rapidly densifies bone in preclinical models.
Composition and Mechanism of the Injectable Hydrogel
The hydrogel is composed of hyaluronic acid and hydroxyapatite, which are naturally occurring body lubricant and the primary mineral that gives bone its strength, respectively. Some variants also include zoledronate, a potent bisphosphonate that inhibits bone breakdown. This compound is designed to mimic natural bone tissue, providing targeted, localized treatment.
Results of Animal Studies
In a study involving 36 rats with osteoporotic bone loss, both systemic treatments (parathyroid hormone or alendronate) and local hydrogel injections were administered. Micro-CT scans at week 8 astonished researchers: hydrogel injections alone increased bone volume by 2.5–3.4 times. The zoledronate-enriched hydrogel (HA2-ZOL) further increased bone density at the injection site by up to 4.8 times, especially when combined with systemic anabolic treatment. The maximum effect was observed within 2–4 weeks, whereas traditional medications often require months or years for similar results (Pioletti, Stadelmann et al., 2025).
Current systemic osteoporosis treatments are slow, leaving patients at high risk of fracture during the initial months of therapy. The new hydrogel offers a minimally invasive and rapid solution. It can be applied immediately after a trauma or upon diagnosis.
The flowbone and EPFL team is now preparing for human clinical trials. If successful, this hydrogel could revolutionize fracture prevention and bone regeneration.
References:
Pioletti, D. P., Stadelmann, V. A., Gerossier, E., Kettenberger, U., & flowbone Team. (2025). Combining systemic and local osteoporosis treatments: A longitudinal in vivo microCT study in ovariectomized rats. Bone, 192,
École Polytechnique Fédérale de Lausanne (EPFL). (2025, January 28). An injectable hydrogel for local bone densification [Press release]. EPFL News.
