The NATO project: nanoparticle-based countermeasures for microgravity-induced osteoporosis

Area of Science:

• Nanomedicine
• Regenerative Medicine
• Biomaterials

Background:

• Space microgravity induces secondary osteoporosis, posing a challenge for astronaut health.
• Nanotechnology offers potential solutions for medical applications in space and on Earth.
• The Nanoparticles and Osteoporosis (NATO) project developed calcium- and strontium-containing hydroxyapatite nanoparticles (nCa-HAP, nSr-HAP).

Purpose of the Study:

• To investigate the effects of nCa-HAP and nSr-HAP on bone remodeling.
• To assess nanoparticle efficacy under normal gravity (1g), simulated microgravity (Random Positioning Machine - RPM), and actual space conditions (International Space Station - ISS).
• To evaluate the potential of nSr-HAP as a countermeasure for microgravity-induced bone loss.

Main Methods:

• Human bone marrow mesenchymal stem cells (hBMMSCs) were treated with nCa-HAP and nSr-HAP.
• Cell differentiation, alkaline phosphatase (ALP) activity, bone marker gene expression, and hydroxyapatite crystal deposition were analyzed.
• Experiments were conducted under 1g, RPM, and ISS conditions.

Main Results:

• nSr-HAP significantly accelerated osteoblast differentiation and bone matrix deposition under 1g conditions.
• nSr-HAP protected against microgravity-induced reduction in ALP activity (RPM).
• nSr-HAP promoted hydroxyapatite crystal deposition in both ISS and 1g environments.

Conclusions:

• Exogenous nSr-HAP can deliver strontium to bone tissue, promoting regeneration.
• nSr-HAP shows potential as a component in synthetic bone substitutes.
• nSr-HAP could be an additive for pharmaceutical or food supplements for systemic bone health benefits.