Injectable radiopaque and bioactive polycaprolactone-ceramic composites for orthopedic augmentation

Area of Science:

• Biomaterials Science
• Orthopedic Engineering
• Materials Science

Background:

• Bone void fillers are crucial in orthopedic and trauma surgery to repair bone defects.
• Current materials often lack ideal injectability, mechanical strength, or osteoconductivity.
• Developing novel injectable bone fillers with enhanced properties is an ongoing research area.

Purpose of the Study:

• To develop and characterize an injectable bone void filler composite material.
• To investigate the effects of incorporating baghdadite particles into polycaprolactone (PCL).
• To evaluate the injectability, mechanical properties, radiopacity, degradation, and cytocompatibility of the PCL-baghdadite composites.

Main Methods:

• Polycaprolactone (PCL) was composited with varying volume percentages of baghdadite particles (1-30%).
• Injectability, setting time, mechanical properties (compressive strength, modulus, flexural strength), radiopacity, degradation, and cytocompatibility were assessed.
• Primary human osteoblasts were cultured on the PCL-10%Bag composite to evaluate cellular response.

Main Results:

• Composites with up to 10% baghdadite (PCL-10%Bag) demonstrated excellent injectability at 75°C with low injection forces (<1.5 kN).
• Setting time was rapid (2.5-3.5 min) post-injection at 37°C.
• Baghdadite incorporation significantly enhanced compressive strength (up to 47.1 MPa) and modulus (up to 741 MPa) compared to pure PCL.
• PCL-10%Bag exhibited superior flexural strength (29.8 MPa) and significant upregulation of osteogenic genes in human osteoblasts.

Conclusions:

• The PCL-10%Bag composite shows excellent injectability, rapid setting, and improved mechanical properties.
• The material demonstrates good cytocompatibility and promotes osteogenic activity, making it suitable for bone regeneration.
• PCL-10%Bag is a promising candidate for injectable bone void filler applications in orthopedics and trauma surgery.