Cu-loaded Brushite bone cements with good antibacterial activity and operability

Bone defect-related surgical procedures are traumatic processes carrying potential inflammation and infection risks in the clinic, which are associated with prolonged antibiotic therapy that promotes bacterial antibiotic-resistance. In the present study, Cu-loaded brushite bone cements were designed, and the properties of the bone cements were evaluated. The setting time of the cement was prolonged from 12 to 50 min as the copper content increased. All cements were anti-washout, and the injectable coefficient of the cements was approximately 88%. Scanning electron microscopy results revealed that the crystal grains grew larger and thicker as the copper content in the cement increased, and brushite was determined to be the dominant crystalline phase for all the cements. However, a small amount of newly formed calcium copper phosphate was observed in the cement. Simultaneously, band shifts were observed in the Fourier transform infrared spectroscopy results at a Cu content of 5%. Moreover, the addition of Cu improved the compressive strength of brushite cements, and all cements were degradable. Furthermore, the Cu-loaded brushite bone cements performed well in inhibiting the growth and proliferation of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and the diameter of the inhibition zone increased with increasing copper content. The study revealed that the Cu-loaded brushite bone cements possessed good cellular affinity to mouse bone marrow stem cells when a lower dose of copper was added in vitro. These results support the great potential of injectable antibacterial brushite bone cement specifically for bone tissue defect-related repair and regeneration.