We plan to implement our aptamer-based drug in patients with osteogenesis imperfecta and other diseases that require bone anabolic treatment, like osteoporosis.
Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk[1]. There are many possible causes, but they can be summarised into two groups: lower-than-normal maximum bone mass, and greater-than-normal bone loss[1].
Although our drug is developed specifically to adapt to the conditions in osteogenesis imperfecta, bone anabolic treatment may help to alleviate conditions that lead to low bone mass by increasing the amount of bone formation via the decrease in sclerostin activity on human osteoblasts with the aptamer drug.
We plan to implement our aptamer-based drug in astronauts on missions in space due to the occurrence of spaceflight osteopenia.
Spaceflight osteopenia refers to the characteristic bone loss of astronauts that occurs during spaceflight. Astronauts lose an average of more than 1% bone mass per month spent in space[2]. There are reasonable concerns that during long-duration flights, excessive bone loss and the associated increase in serum calcium ion levels will interfere with the astronauts' ability to execute mission tasks and may result in irreversible skeletal damage[3].
Bone remodels in response to stress in order to maintain constant strain energy per bone mass throughout. This is achieved by growing more dense in areas experiencing high stress, while resorbing in density in areas experiencing low stress[4].
Although exercise has been tried as a way of preventing bone loss, it has not been shown to be successful. This may be in part due to lack of adequately designed studies (no controlled study had been done as of 2005, either in space or using bedrest as an attempt to simulate conditions which lead to bone loss). It is not known whether a different exercise regimen (perhaps including larger loads than past ones) would be effective.[5] Other countermeasures against spaceflight osteopenia include increasing dietary calcium[5], vitamin D[5] and using clay[6] to retain calcium.
As the goal of the prevention of spaceflight osteopenia is to retain the amount of bone present in astronauts throughout the mission, our drug may be used to artificially increase the rate of bone anabolism in astronauts to prevent excessive bone resorption and raising serum calcium ion levels.
[1]: WHO Scientific Group on the Prevention and Management of Osteoporosis (2000 : Geneva, Switzerland) (2003). Prevention and management of osteoporosis: report of a WHO scientific group. pp. 7, 31. [2] Scott K (2017). Endurance: A Year in Space, a Lifetime of Discovery. With Margaret Lazarus Dean. Alfred A. Knopf, a division of Penguin Random House. p. 174. [3] "Space Bones". NASA. October 1, 2001. [4] Marzban A (January 1, 2008). "Different approaches of remodeling of bone to predict bone density distribution of proximal femur". [5] Cavanagh P; Licata A & Rice A (2005), "Exercise and pharmacological countermeasures for bone loss during long-duration space flight", Gravitational and Space Biology, 18 (2): 39–58. [6] Suzanne U (April 3, 2008); "Mud, Mud, Glorious Mud", The Magazine of the California Academy of Sciences.
