Injectable P24-Si-CaP/GelMA composite hydrogel for repairing bone defects

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Severe bone defects present significant clinical challenges.
• Existing Si-CaP materials have limitations in application convenience and degradability.
• There is a need for advanced injectable scaffolds for bone defect repair.

Purpose of the Study:

• To develop an injectable, light-curable P24-Si-CaP/GelMA composite hydrogel.
• To enhance the osteogenic capacity of Si-CaP material via P24 peptide grafting.
• To evaluate the biocompatibility and bone regeneration potential of the novel hydrogel.

Main Methods:

• Fabrication of P24-Si-CaP/GelMA composite hydrogel.
• Characterization of material properties (gelation, mechanical strength, porosity, hydrophilicity).
• In vitro assessment of rat bone marrow mesenchymal stem cell (rBMSC) response and osteogenic differentiation.
• In vivo evaluation of bone regeneration in a rat cranial defect model using micro-CT and histological analysis.

Main Results:

• The P24-Si-CaP/GelMA hydrogel (20% mass ratio) demonstrated optimal gelation, mechanical strength, porosity, and hydrophilicity.
• In vitro studies showed enhanced rBMSC migration, osteogenic differentiation, and mineralization with no cytotoxicity.
• In vivo results indicated significantly higher new bone formation and defect closure in the P-Si/G group compared to controls after 8 weeks.

Conclusions:

• The injectable P24-Si-CaP/GelMA hydrogel is biocompatible and osteoinductive.
• The P-Si/G hydrogel promotes effective bone regeneration in vivo.
• This composite hydrogel represents a promising injectable scaffold for bone tissue engineering applications.