A pH-Triggered, Self-Assembled, and Bioprintable Hybrid Hydrogel Scaffold for Mesenchymal Stem Cell Based Bone Tissue...

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Tissue Engineering

Background:

• Bone tissue engineering aims to restore bone function lost due to trauma or disease.
• Successful bone regeneration requires scaffolds that support cell activity and promote bone formation.
• Mesenchymal stem cells (MSCs) are crucial for bone regeneration, necessitating scaffolds that enhance their function.

Purpose of the Study:

• To develop and characterize a novel composite nanoparticle hydrogel for enhanced MSC-based bone tissue regeneration.
• To evaluate the biocompatibility, osteoinductivity, and bone formation capacity of the developed hydrogel.
• To explore the potential of the hydrogel as a scaffold for osteoprogenitor cell-based bone regeneration.

Main Methods:

• Fabrication of a composite hydrogel by combining carboxymethyl chitosan (CMCh) and amorphous calcium phosphate (ACP).
• Preparation of the CMCh-ACP hydrogel via pH-triggered controlled assembly.
• In vitro assessment of MSC proliferation, adhesion, and osteogenic differentiation.
• In vivo evaluation of bone formation efficiency and maturity in an ectopic osteogenesis model.

Main Results:

• The CMCh-ACP hydrogel demonstrated excellent biocompatibility and supported MSC proliferation and adhesion.
• The hydrogel exhibited intrinsic osteoinductivity, promoting osteoblastic gene expression in MSCs.
• In vivo studies showed enhanced bone formation and maturity with the CMCh-ACP scaffold.
• The scaffold suppressed bone resorption during long-term ectopic osteogenesis.

Conclusions:

• The pH-responsive, self-assembled CMCh-ACP hydrogel is injectable and bioprintable.
• This novel hydrogel shows significant potential as a scaffold for osteoprogenitor cell-based bone tissue regeneration.
• The CMCh-ACP hydrogel represents a promising advancement in bone regenerative medicine.