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Biologic Nanoparticles Calcify and Form Bacteria‐like Biofilm In Vitro
Author(s) -
Hunter Larry W,
Lieske John C,
Miller Virginia M
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.593.14
Subject(s) - biofilm , bacteria , chemistry , exopolymer , microbiology and biotechnology , microcarrier , polysaccharide , biophysics , bacterial cell structure , biology , cell , biochemistry , genetics
Biologic nanoparticles (NPs) isolated from human atheromas propagate and form an apatite shell when placed in cell‐culture conditions. These characteristics led us to hypothesize that NPs might derive from microorganisms. NPs isolated from human aortic aneurysms and maintained in DMEM, 10% fetal bovine serum at 37 o C increased both in density (measured in nephelometric turbidity units, NTU) from 1.6 to 107.1 and in diameter (from < 0.2 μm to 0.5‐1 μm) over the course of 12 days. Crystals present on the surface of NPs were found by electron microscopy/elemental analysis to be composed of Ca 2+ and P i . NPs adhered to the surface of the culture flasks, forming a biofilm strikingly similar to that seen in microbial communities. Confocal laser scanning microscopy showed that the biofilm stained positively with concanavalin‐A, a probe for mannose and glucose, both major constituents of microbial biofilm matrix exopolysaccharides. Further, the biofilm stained positively by Bac Light Green, a bacteria‐specific cell wall label, as well as the lipid membrane‐selective dye Vybrant CM‐DiI. These results reveal that calcifying NPs isolated from human atheromas share characteristics common to bacteria since they propagate when placed in cell culture conditions, form a biofilm containing polysaccharides, and stain with agents that recognize bacterial components. Supported by grants from the Fetzer Foundation and NIH HL88988.