Inorganic polyphosphates: biologically active biopolymers for biomedical applications

Area of Science:

• Biochemistry
• Cell Biology
• Biomaterials Science

Background:

• Inorganic polyphosphate (polyP) is a ubiquitous biopolymer in prokaryotic and eukaryotic organisms.
• Recent research highlights polyP's role in human bone formation, influencing key cellular processes.
• The morphogenetic activity of polyP on bone cells is an emerging area of investigation.

Purpose of the Study:

• To investigate the dual effects of inorganic polyphosphate (polyP) on bone-forming osteoblasts and bone-resorbing osteoclasts.
• To elucidate the mechanisms by which polyP influences bone mineralization and osteoclast differentiation.
• To explore the potential role of polyP in hemostasis and related disorders.

Main Methods:

• Cell culture of osteoblasts and osteoclast precursors.
• Exposure of cells to calcium complex of polyP (polyP/Ca(2+)).
• Analysis of cytokine expression, mineralization, osteoclast differentiation, and BMP-2 release.

Main Results:

• PolyP/Ca(2+) complex demonstrated a dual effect on osteoblasts and osteoclasts.
• PolyP stimulated osteoblast mineralization via cytokine expression.
• PolyP suppressed osteoclast differentiation and activity, reducing bone resorption.
• PolyP increased the release of bone morphogenetic protein 2 (BMP-2).

Conclusions:

• Inorganic polyphosphate (polyP) modulates bone remodeling by promoting osteoblast activity and inhibiting osteoclast function.
• PolyP's influence on BMP-2 release suggests a significant role in anabolic bone processes.
• PolyP also acts as a hemostatic regulator, affecting blood coagulation and fibrinolysis, with implications for inflammatory and procoagulant conditions.