In bone regeneration rests new hope for osteoporosis relief

A Pune lab has synthesised a nano biomaterial which could improve the way we treat osteoporosis. The achievement is significant as it holds out the possibility of tissue regeneration and provides new hope to patients suffering from osteoporosis — a condition that mainly affects women after menopause when hormone deficiency leads to a decline in the absorption of calcium in the bones, making them weak and susceptible to fractures.

Currently, a commercial formulation, Teriparatide, is used to treat bone degeneration caused by hormonal deficiency.

Dr Geetanjali Tomar, a Department of Science and Technology scientist at the Savitribai Phule Pune University, has synthesised a nano biomaterial from stem cell culture taken from human gums (gingiva). It is called ‘hydroxyapatite-parathyroid nano-conjugate’.

Her research paves the way for enhanced effectiveness of the current therapy for tissue regeneration.

Hydroxyapatite is a natural component of bones. It is composed of calcium and phosphate and is the mineral content in the bone. Parathyroid hormone (PTH) is produced in our body. It is also available as Teriparatide (approved by the United States Food and Drug Administration or FDA). “We have synthesised nano-sized particles of hydroxyapatite and physically adsorbed the parathyroid hormone to it,” explains Dr Tomar.

How will this new synthesis help osteoporosis treatment? According to Dr Tomar, Teriparatide treatment (which uses PTH) has certain limitations. The administered hormone gets unevenly distributed in the body and does not reach the target tissue, namely the bones. Consequently, multiple but intermittent doses have to be administered. However, as per FDA guidelines, PTH therapy cannot be extended beyond two years because of side effects from long-term use.

As a result, a patient receives 8-9 doses of PTH in the two-year window. Unfortunately, the ‘clearance time’ of the hormone from the body is also very low and it gets very little time to act. Therefore, Teriparatide is unable to completely cure the osteoporotic condition or significantly regenerate bone tissue. It can only reduce the risk of fracture.

This is where ‘bioengineering’ walks in.

Combined effect

Dr Tomar aimed at improvising the current treatment by synthesising a formulation that would specifically reach the bone tissue to minimise its uneven distribution. The research team led by her combined hydroxyapatite and PTH into a nano formulation, “so that both would reach the bone simultaneously.”

As a result, there was a synergistic effect in terms of regeneration of degraded tissue, improving the overall efficacy of the treatment during the two-year window.

The new nano biomaterial formulation needs to be further analysed. Tomar has so far conducted initial experiments on small animals, such as mice. But before taking it up for clinical application, it needs to be tested on large animals such as dogs, horses, and so on. “We are aiming to take up this formulation for synthesis of bone implants,” she says.

Tomar’s lab is one of the few in the country working with stem cells derived from human gums. Most others source stem cells from bone marrow, alveolar bone, periodontal ligament, umbilical cord, endometrium, breast milk, adipose tissue and so on. Tomar says she chose gums because it is easier to harvest stem cells from them. Apparently, gum tissues that are usually discarded after root canal treatment, gingivectomy, crown lengthening and other dental procedures can yield millions of cells.

“We basically collect waste tissue from dental clinics. A small piece of gingiva (approximately 1mm x 1mm) yields a large number of cells (almost a million) in a few days. The quality of cells is very good, and they remain healthy in laboratory conditions for very long periods,” notes Dr Tomar.

Moreover, harvesting tissue from bone marrow, alveolar bone, periodontal ligament and adipose tissue is a highly invasive procedure. Though umbilical cord, endometrium and breast milk are easy to harvest, their availability and cell yield is limited.

Putting the Pune lab’s synthesis into medical use might take time. In fact, it would require an academia-industry collaboration as well as a close-knit association between clinicians and academicians. A state-of-the-art infrastructure at the university would also be needed to conduct extensive tests. Support from the government’s funding agencies would boost the ongoing research, feels Dr Tomar.

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