Experimental studies on a new bioactive bone cement: hydroxyapatite composite resin

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Polymer Chemistry

Background:

• Bone cements are crucial for orthopedic procedures, but current materials like polymethylmethacrylate (PMMA) have limitations.
• There is a need for bone void fillers with enhanced mechanical properties and improved biocompatibility.
• Hydroxyapatite composite resins offer potential for bioactive bone regeneration.

Purpose of the Study:

• To develop and evaluate a novel hydroxyapatite composite resin (CAP) bone cement.
• To assess the mechanical strength of CAP in comparison to PMMA bone cement.
• To investigate the biological response and bone integration of CAP implants in vivo.

Main Methods:

• CAP was synthesized using 80% hydroxyapatite granules and a bis-phenol-A glycidyl methacrylate-based resin.
• Mechanical properties (compressive strength, tensile strength, fracture toughness) of CAP were measured.
• CAP was implanted into rabbit femoral condyles to evaluate bone formation and interface characteristics.

Main Results:

• CAP exhibited a compressive strength of 260 MPa, approximately three times that of PMMA.
• CAP demonstrated superior tensile strength and fracture toughness compared to PMMA.
• Histological analysis revealed new bone formation directly on CAP surfaces by 8 weeks, with no fibrous tissue encapsulation.

Conclusions:

• Hydroxyapatite composite resin (CAP) possesses significantly enhanced mechanical properties over PMMA bone cement.
• CAP demonstrates excellent biocompatibility and osteoconductive potential, promoting direct bone apposition.
• CAP is a promising bioactive bone cement for orthopedic applications, offering improved strength and bone integration.