The acute inflammatory response to copper(II)-doped biphasic calcium phosphates

Area of Science:

• Biomaterials Science
• Immunology
• Orthopedics

Background:

• Septic and aseptic loosening of bone-implanted biomaterials are often linked to infection and inflammation.
• Modulating the immune and skeletal cell crosstalk is crucial for improving biomaterial performance.
• Cation-doping of calcium phosphates offers a strategy to control biomaterial-induced inflammation and enhance osteoimmunomodulatory properties.

Purpose of the Study:

• To synthesize and investigate the osteoimmunomodulatory properties of copper(II) ions-doped biphasic calcium phosphate (BCP) biomaterials.
• To evaluate the in vitro inflammatory response of human primary polymorphonuclear neutrophils (PMNs) to doped and undoped BCP.
• To assess the in vivo inflammatory effects and PMN recruitment using a mouse air pouch model.

Main Methods:

• Synthesis of copper(II) ions-doped and undoped BCP powders via a wet method.
• In vitro analysis of PMN inflammatory response using ELISA and zymography, with and without LPS stimulation.
• In vivo assessment of PMN recruitment in a mouse air pouch model using flow cytometry.

Main Results:

• Copper(II)-doped BCP significantly increased IL-8 and GRO-α secretion by PMNs in vitro, without affecting MIP-1β, TNF-α, or MMP-9.
• In vivo studies demonstrated increased PMN recruitment with copper(II)-doped BCP compared to undoped BCP.
• The material exhibited specific osteoimmunomodulatory effects, modulating the inflammatory environment.

Conclusions:

• Copper(II) doping of BCP effectively modulates the inflammatory response of neutrophils.
• The induced moderate inflammation may enhance bacterial clearance, complementing the material's antimicrobial potential.
• Copper(II)-doped BCP offers promising applications for prosthesis coating and bone reconstruction by fine-tuning the inflammatory environment.