Microporous nanofibrous fibrin-based scaffolds for bone tissue engineering

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Fibrotic response to synthetic polymers hinders tissue engineering applications.
• Controlling pore size and interconnections in porous polymers is challenging for understanding healing.
• Natural polymers offer potential but require tailored fabrication for optimal outcomes.

Purpose of the Study:

• To develop a novel method for fabricating natural polymer/calcium phosphate composite scaffolds.
• To achieve tight control over scaffold pore size, pore interconnection, and calcium phosphate deposition.
• To evaluate the in vitro and in vivo performance of these composite scaffolds for bone regeneration.

Main Methods:

• Fabrication of microporous, nanofibrous fibrin scaffolds using sphere-templating.
• Creation of composite scaffolds via calcium phosphate solution deposition or incorporation of nanocrystalline hydroxyapatite (nHA).
• Assessment of scaffold structure (SEM), cell behavior (osteoblast-like cells), degradation, and bone formation in a mouse calvarial defect model.

Main Results:

• Fibrin scaffolds exhibited highly porous and interconnected structures.
• Osteoblast-like cells attached, spread, and formed multiple layers on scaffolds, with enhanced alkaline phosphatase activity and gene expression on mineralized scaffolds.
• Scaffolds promoted bone formation in vivo, with enhanced effects observed with the addition of recombinant human bone morphogenetic protein-2 (rhBMP-2).

Conclusions:

• The developed natural polymer/calcium phosphate composite scaffolds offer controllable architecture and support osteogenic differentiation.
• These scaffolds demonstrate efficacy in promoting bone regeneration in a calvarial defect model.
• The findings suggest these composite scaffolds are promising biomaterials for bone tissue engineering applications.