Nanobacteria: Living or crystalline? New evidence

November, 2008

Background

Nanotechnology is an exciting field that has revealed novel nanoscale properties of commonplace materials such as carbon and silicon. However, the discovery of calcifying nanoparticles (CNPs) (or 'nanobacteria') in human blood and blood products has raised concerns. In blood, CNPs form a calcium phosphate coating associated with diverse calcification-related health problems, such as cardiovascular disease, kidney stones, gall stones, Alzheimer disease and some cancers. Some believe CNPs to be a new class of living organism while others think they are non-living protein or crystal precipitates. The controversy has been fuelled by claims that CNPs self-propagate (one of the key defining criteria of living organisms). Concerns for human health are increased by observations that CNPs are resistant to heat and gamma irradiation normally sufficient to kill bacteria. In addition, CNPs cannot be trapped by commonly used sterilization filters because of their minute size.

• Mathew G, McKay DS, Çiftçioglu N (2008) Do blood-borne calcifying nanoparticles self-propagate? International Journal of Nanomedicine;3 (2) 265-275 (PDF:1.51MB)

Summary:

Mathew et al (2009) recently investigated the possibility of CNP self propagation under physiological conditions using BioStation IM. It was demonstrated that CNPs increase in size and increase in number linearly over a period of five days. In contrast, negative controls without CNPs and inorganic hydroxyapatite in similar culture conditions did not show any increase in particle formation. Using electron microscopy, particles were shown to have budding-like structures (similar to those seen in yeasts and some bacteria) on their surface. CNPs appear to be sensitive to environment, forming 'igloo-like' structures on their surface (due to calcium and phosphate deposition) in conditions of depleted serum or protein concentrations. These igloos can reach several microns in thickness and contain tiny nanometre-sized CNPs, which continue to grow but at a slower rate in a semi 'dormant' state. When serum and/or protein are replenished the CNPs are released. This characteristic of CNPs allows them to exist in body fluids as free nanometre-sized particles and also as thick plaques in calcified soft tissues.

The authors (from Nanobac Pharmaceuticals Inc. Houston Texas, USA) were the first group to produce video footage of CNPs in realtime (Nov 2006 link). They showed that a decalcifying agent dissolved calcified structures while the particles inside seem unaffected and were released to potentially begin the calcification process again. By contrast, inorganic crystals exposed to the same agent are dissolved without releasing nanoparticles.