Scientists have developed a nanoparticle that can stimulate growth of bone forming cells and deliver the drug used for osteoporosis straight to the affected area in rats which can show a way forward for reversal of osteoporosis in humans.
The study was published recently in the online version of European Journal of Pharmaceutical Sciences. Further clinical trials are needed before reaching the medical shelf.
About 9 million bone fractures occur each year due to osteoporosis, a progressive bone disease in which bone loses both its mass and density, thereby becoming weaker. Current treatment regimes involve restricting further bone damage, but not restoring previous strength. Zoledronic acid (ZOL) is the commonly used drug; it has successfully reduced risk of fracture in post- menopausal women. However, prolonged use of the drug can cause several adverse effects like unwanted bone changes.
A team of engineers and pharmacologists from IISc and Al-Ameen college of Pharmacy, Bangalore, has come up with a modified ZOL drug, which has proved to be effective in treatment of postmenopausal osteoporosis. What makes this novel mode of treatment even more special is the use of extremely small particles, called “nanoparticles”, for drug delivery.
“We have designed a new formulation, where the ZOL is first adsorbed on nanoparticles of hydroxyapatite and carried to osteoporotic bone by intravenous injection”, said lead author Deepak Kumar Khajuria. “We are able to demonstrate successfully that this formulation not only prevents further bone loss, but also stimulates bone growth”, he added.
The nanoparticles are made of synthetic hydroxyapatite (HA). HA is naturally present in our bodies: it makes up bone mineral and the matrix of teeth. It stimulates bone forming cells. The modified ZOL drug used in the study has a high affinity to bone, and prevents further bone loss.
The team used 12 week old female rats, whose ovaries were removed so that bone remodeling would not occur. Various doses of HA, ZOL and a combination of both were tested on the rats.
Three months after the treatment, the lumbar vertebra and femur (thigh bone) was tested for mechanical properties. Both showed better strength and structure after the combined treatment. A host of sensitive biochemical tests to predict whether new bone growth occurred were also carried out, all of which showed improvement with the combined treatment.