Highly Stable Amorphous (Pyro)phosphate Aggregates: Pyrophosphate as a Carrier for Bioactive Ions and Drugs in Bone...

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Materials Chemistry

Background:

• Pyrophosphate is recognized for its complexation and hydrolysis properties, yet its application in active ionophores for bone repair remains underexplored.
• Existing bone repair strategies often lack controlled ion release and antibacterial properties.

Purpose of the Study:

• To develop a novel method for preparing magnesium-calcium (pyro)phosphate aggregates (AMCPs) using ultrasound.
• To investigate the potential of AMCPs as active ionophores for bone repair applications, focusing on ion release, bioactivity, and cellular responses.

Main Methods:

• A simple and efficient ultrasonic method was employed to synthesize amorphous magnesium-calcium (pyro)phosphate aggregates (AMCPs).
• The composition of AMCPs was tailored by adjusting the molar ratio of calcium and magnesium ions.
• In vitro studies assessed ion release kinetics, bacteriostatic effects, and the impact of AMCPs on osteoblast precursor cells (MC3T3-E1) and human umbilical vein endothelial cells (HUVECs).

Main Results:

• AMCPs exhibited stable amorphous structures, surface negativity, and complexing abilities, enabling long-term controlled release of Ca²⁺, Mg²⁺, and P ions, as well as drugs.
• Pyrophosphate imparted a significant bacteriostatic effect.
• Optimized AMCPs (15 wt% Mg²⁺) demonstrated enhanced stimulation of osteoblast proliferation, attachment, differentiation, and angiogenesis in vitro.

Conclusions:

• Pyrophosphate serves as an effective carrier for bioactive ions in bone repair materials.
• The developed AMCPs possess multiple active functions, including controlled ion release, antibacterial properties, and promotion of osteogenesis and angiogenesis, indicating their potential for diverse bone repair scenarios.