Osteoporosis is typically treated with orally administered drugs, which may take up to a year to have a noticeable effect. A new injectable hydrogel, however, is claimed to drastically boost bone density in as little as two weeks.
The disease occurs when there's an imbalance between a person's osteoblasts – which are bone-building cells – and their osteoclasts, which are bone-degrading cells.
Ordinarily, osteoclasts serve a beneficial function by reshaping bones so they become stronger over time. When those cells outnumber the osteoblasts, though, there's an overall loss of bone tissue, resulting in weaker, more fragile bones.
Treatment usually involves the use of pharmaceuticals that either decrease the rate at which old bone tissue is broken down, or increase the rate at which new bone tissue is produced.
Either way, it can take as long as 12 months before the medication makes much of a difference, during which time the patient may suffer serious bone injuries. The drugs can also produce a number of unpleasant side effects, plus they simply don't work that well on some people.
That's where the new hydrogel comes in. It was created by Prof. Dominique Pioletti and colleagues at Switzerland's EPFL university, and is now being developed further by spinoff company flowbone.
The substance's active ingredients include hyaluronic acid – a gooey substance which is produced naturally by the body's connective tissue – and nanoparticles of hydroxyapatite, which is the primary component in bone tissue.
In lab tests, the hydrogel was injected directly into weak spots in the leg bones of rats with bone loss. Within just two to four weeks, there was a two- to three-fold increase in bone density at the injection sites. The improvements didn't stop there, however.
In another group of rats, the animals additionally underwent a conventional bone-building hormone treatment. What's more, the hydrogel that they received was mixed with a drug that reduces bone degradation. This time around, bone density increased up to 4.8-fold.
Although the administered hormones might still produce unwanted side effects in such a scenario, they would be doing so for a much shorter period of time than is currently the case.
The scientists are now waiting to receive regulatory approval for the hydrogel, after which they plan on starting human trials.
"In this work, we demonstrate for the first time that a combined therapy of a systemically delivered drug and local injection of our hydrogel delivers a rapid increase in bone density, and could therefore transform the prevention of osteoporosis fractures," says Pioletti.
A paper on the research – which also involved Dr. Vincent Stadelmann from the Schulthess Klinik, Zurich – was recently published in the journal Bone.
