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Effect of calcium carbonate particle shape on phagocytosis and pro-inflammatory response in differentiated THP-1 macrophages

Journal Article · · Biochemical and Biophysical Research Communications
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  1. Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2217-14 Hayashi-cho, Takamatsu, Kagawa 761-0395 (Japan)
  2. Shiraishi Central Laboratories Co., Ltd., 4-78 Motohama-cho, Amagasaki, Hyogo 660-0085 (Japan)

Phagocytosis is a physiological process used by immune cells such as macrophages to actively ingest and destroy foreign pathogens and particles. It is the cellular process that leads to the failure of drug delivery carriers because the drug carriers are cleared by immune cells before reaching their target. Therefore, clarifying the mechanism of particle phagocytosis would have a significant implication for both fundamental understanding and biomedical engineering. As far as we know, the effect of particle shape on biological response has not been fully investigated. In the present study, we investigated the particle shape-dependent cellular uptake and biological response of differentiated THP-1 macrophages by using calcium carbonate (CaCO{sub 3})-based particles as a model. Transmission electron microscopy analysis revealed that the high uptake of needle-shaped CaCO{sub 3} particles by THP-1 macrophages because of their high phagocytic activity. In addition, the THP-1 macrophages exposed to needle-shaped CaCO{sub 3} accumulated a large amount of calcium in the intracellular matrix. The enhanced release of interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α) by the THP-1 macrophages suggested that the needle-shaped CaCO{sub 3} particles trigger a pro-inflammatory response. In contrast, no pro-inflammatory response was induced in undifferentiated THP-1 monocytes exposed to either needle- or cuboidal-shaped CaCO{sub 3} particles, probably because of their low phagocytic activity. We also found that phosphate-coated particles efficiently repressed cellular uptake and the resulting pro-inflammatory response in both THP-1 macrophages and primary peritoneal macrophages. Our results indicate that the pro-inflammatory response of macrophages upon exposure to CaCO{sub 3} particles is shape- and surface property-dependent, and is mediated by the intracellular accumulation of calcium ions released from phagocytosed CaCO{sub 3} particles. - Highlights: • Needle-shaped CaCO{sub 3} particles are phagocytized by macrophages. • Needle-shaped CaCO{sub 3} particles induce intracellular accumulation of calcium ions. • Needle-shaped CaCO{sub 3} particles induce pro-inflammatory responses. • Surface-coating with phosphate decreases adverse effects on macrophages.

OSTI ID:
22719040
Journal Information:
Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 2 Vol. 490; ISSN 0006-291X; ISSN BBRCA9
Country of Publication:
United States
Language:
English