Resorption analysis of deproteinized cancellous bovine bone

Area of Science:

• Biomaterials Science
• Skeletal Biology
• Tissue Engineering

Background:

• Commercially available deproteinized cancellous bovine bone (DPBB) is often considered non-absorbable.
• Stoichiometric hydroxyapatite (HA) is generally not resorbed by osteoclasts.
• Calcium-deficient, carbonate-rich apatites, like octacalcium phosphate (OCP) hydrolysate, can be resorbed.

Purpose of the Study:

• To analyze the chemical composition of DPBB.
• To compare the tissue reactions to DPBB and OCP hydrolysate after implantation in mouse bone marrow.
• To investigate the resorption mechanism of DPBB by osteoclasts.

Main Methods:

• Chemical analysis of DPBB using X-ray diffraction and Fourier transform infrared spectroscopy.
• Implantation of DPBB and OCP hydrolysate into mouse bone marrow.
• Micro-computed tomography (Micro-CT) analysis for bone formation and resorption.
• Transmission electron microscopy (TEM) to examine osteoclast ultrastructure.

Main Results:

• DPBB was identified as a carbonate-rich apatite.
• Both DPBB and OCP hydrolysate showed significant bone formation at 2 weeks, followed by gradual resorption.
• At 12 weeks, osteoclasts actively resorbed DPBB, exhibiting ultrastructural features similar to those resorbing native bone.
• Osteoclasts attached to OCP hydrolysate showed irregular ruffled border morphology.

Conclusions:

• DPBB is an absorbable bone graft material.
• The resorption of apatitic materials by osteoclasts may be influenced by the size and orientation of HA crystals.
• DPBB's resorptive capacity suggests its suitability for bone regeneration applications where remodeling is desired.