VEGF expression in mesenchymal stem cells promotes bone formation of tissue-engineered bones

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Stem Cell Biology

Background:

• Tissue-engineered bone grafts aim to restore bone defects.
• Vascularization is crucial for the survival and integration of engineered grafts.
• Mesenchymal stem cells (MSCs) are promising for bone regeneration.

Purpose of the Study:

• To evaluate the in vivo vascularization and bone formation of tissue-engineered bone using VEGF-transfected MSCs.
• To assess the efficacy of VEGF gene delivery in enhancing osteogenesis within a nano-hydroxyapatite/collagen scaffold.

Main Methods:

• Rat bone marrow MSCs were transfected with VEGF165.
• VEGF expression was confirmed via RT-PCR and immunohistochemistry.
• MSCs were co-cultured with nano-hydroxyapatite/collagen (NHAC) scaffolds.
• Tissue-engineered constructs were implanted in mice for in vivo evaluation.
• Vascularization and new bone formation were quantified using immunohistochemistry.

Main Results:

• VEGF165 gene expression was confirmed post-transfection and selection.
• VEGF-transfected MSCs showed significantly higher alkaline phosphatase activity.
• In vivo analysis revealed enhanced vascularization and bone-like tissue formation in VEGF-treated grafts.
• Control grafts exhibited limited bone-like and fibrotic tissue.

Conclusions:

• VEGF165-transfected bone marrow MSCs significantly promote vascularization in tissue-engineered bone.
• This approach enhances ectopic osteogenesis and bone formation.
• VEGF gene modification holds potential for improving bone regeneration strategies.