Advancing Scaffold Architecture for Bone Tissue Engineering: A Comparative Study of 3D-Printed β-TCP Constructs in...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Stem Cell Biology

Background:

• Scaffold architecture is crucial for bone regeneration, but pore size effects under dynamic culture are not fully understood.
• Optimizing scaffold design is essential for effective bone tissue engineering and clinical applications.

Purpose of the Study:

• To investigate the impact of scaffold pore size on osteogenic differentiation of porcine bone marrow-derived mesenchymal stem cells (pBMSCs).
• To evaluate pBMSC response in a rotational oxygen-permeable bioreactor system (ROBS) using 3D-printed beta-tricalcium phosphate (β-TCP) scaffolds.

Main Methods:

• Fabrication of β-TCP scaffolds with 500 µm and 1000 µm pore sizes using 3D printing.
• Seeding pBMSCs onto scaffolds and culturing in a ROBS for 7 and 14 days under dynamic perfusion.
• Analysis of osteogenic gene expression (Runx2, BMP-2, ALP, Osx, Col1A1, Ocl) and alkaline phosphatase (ALP) activity.

Main Results:

• Scaffolds with 1000 µm pores showed significantly higher expression of early osteogenic markers and faster upregulation of Osteocalcin.
• Higher ALP activity was observed in the 1000 µm pore size group, indicating enhanced osteogenic differentiation.
• Larger pores supported homogeneous cell distribution and high cell viability despite lower mechanical strength.

Conclusions:

• Larger scaffold pore sizes (1000 µm) promote enhanced osteogenic differentiation of pBMSCs in dynamic bioreactor culture.
• Improved nutrient transport and fluid flow in larger pores likely contribute to better cell response and early osteogenic commitment.
• Findings support the use of larger-pore scaffolds in bioreactor preconditioning for efficient bone tissue engineering and reduced culture time.