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Updated: May 20, 2026
Isolation of Mouse Interstitial Valve Cells to Study the Calcification of the Aortic Valve In Vitro
Published on: May 10, 2021
Aortic valve-derived calcifyng nanoparticles: no evidence of life
Ignasi Barba1, Eduardo Villacorta, Miguel-Angel Bratos-Perez
1Institut de Recerca, Àrea del Cor, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain. ignasi.barba@vhir.org
Introduction And Objectives:
Calcifying nanoparticles, also known as "nanobacteria," are very small bacteria-like structures (0.1-0.5 μm) with the ability to facilitate the precipitation and growth of calcium phosphate in pathological conditions and have been associated with aortic valve calcification. The status of nanobacteria is controversial; some have proposed that they are a new class of living organism while others describe calcifying nanoparticles as mineralo-fetuin complexes. The objective of the present study is to elucidate if calcifying nanoparticles are living entities, based on whether or not they have metabolic activity, a characteristic of life, irrespective of their composition.
Methods:
Calcifying nanoparticles were grown from 6 different valves randomly chosen among 84 consecutively explanted aortic valves, as described in the literature. The (1)H-NMR spectra were acquired from calcifying nanoparticles culture media to assess metabolic changes and the presence of 16sRNA in the culture media was investigated by real-time polymerase chain reaction.
Results:
After 6 weeks in culture, calcifying nanoparticles could be seen clearly attached to the surface of culture flasks. All samples were negative for 16sRNA, discarding the presence of known bacteria. (1)H-NMR spectra showed no difference between calcifying nanoparticles and 6-week-old sterile culture media maintained under the same conditions.
Conclusions:
Our results show that calcifying nanoparticles cannot be considered as living organisms.
