Uniform tricalcium phosphate beads with an open porous structure for tissue engineering

Area of Science:

• Biomaterials Science
• Materials Engineering
• Tissue Engineering

Background:

• Tricalcium phosphate (TCP) is a biocompatible ceramic widely used in bone regeneration.
• Developing porous TCP scaffolds with controlled pore architecture is crucial for effective bone tissue engineering.
• Existing fabrication methods often face challenges in achieving uniform pore distribution and interconnectivity.

Purpose of the Study:

• To develop a simple fluidic device method for fabricating uniform micro and macro porous tricalcium phosphate (TCP) beads.
• To characterize the pore structure and interconnectivity of the fabricated TCP beads.
• To evaluate the in vivo biocompatibility and tissue integration of the porous TCP beads.

Main Methods:

• Fabrication of micro-porous TCP beads using an aqueous gelatin/TCP mixture in a toluene continuous phase, followed by freezing, freeze-drying, and calcination.
• Fabrication of macro-porous TCP beads using an oil-in-water-in-oil (O/W/O) emulsion templating method within the fluidic device, followed by freeze-drying and calcination.
• Characterization using scanning electron microscopy (SEM) and porosimetry; in vivo evaluation via subcutaneous implantation in mice and histological analysis.

Main Results:

• Uniform micro and macro porous TCP beads were successfully fabricated using the fluidic device.
• Macro-porous TCP beads exhibited large pore sizes and excellent interconnectivity.
• Histological analysis confirmed penetration of host tissue into the macro-pores of the implanted TCP beads within 1-4 weeks.

Conclusions:

• A simple fluidic device enables the fabrication of uniform micro and macro porous TCP beads.
• The macro-porous TCP beads possess a highly open structure, promoting host tissue infiltration.
• These macro-porous TCP beads show significant potential as injectable scaffolds for bone tissue engineering applications.