[EXPERIMENTAL STUDY ON TISSUE ENGINEERED BONES CONSTRUCTED BY HUMAN BONE MORPHOGENETIC PROTEIN 2 GENE-MODIFIED HUMAN...

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Gene Therapy

Background:

• Tissue engineered bone offers a promising alternative for bone defect repair.
• Human bone marrow mesenchymal stem cells (hBMSCs) are a viable cell source for bone regeneration.
• Bone morphogenetic protein 2 (BMP-2) is a key factor in osteogenesis.

Purpose of the Study:

• To evaluate the bone regeneration capacity of cell-tissue engineered bone constructed using hBMSCs genetically modified to express human bone morphogenetic protein 2 (hBMP-2).
• To assess the stability and efficacy of hBMP-2 gene expression and secretion in engineered bone constructs.
• To investigate the in vivo osteogenic potential of these engineered constructs.

Main Methods:

• Cloning and construction of a eukaryotic expression system for the full-length hBMP-2 gene.
• Transduction of hBMSCs with the hBMP-2 gene using lipidosomes, with control groups for comparison.
• Assessment of hBMP-2 expression and secretion via RT-PCR, dot-ELISA, immunohistochemistry, and ALP activity assays.
• Construction of tissue engineered bone by seeding transfected hBMSCs onto hydroxyapatite (HA) scaffolds.
• In vivo implantation of engineered bone constructs into nude mice and evaluation of new bone formation through histological staining (HE and alcian blue).

Main Results:

• Transfected hBMSCs demonstrated stable expression and secretion of exogenous hBMP-2, confirmed by RT-PCR, dot-ELISA, and positive immunohistochemical staining.
• Significantly higher alkaline phosphatase (ALP) activity was observed in hBMP-2 transfected hBMSCs compared to control groups (P<0.05).
• Engineered bone constructs showed good cell attachment and growth on HA scaffolds.
• In vivo studies revealed significant new bone formation in constructs with hBMP-2 modified hBMSCs (Group A), with limited new bone formation in control groups.

Conclusions:

• Cell-tissue engineered bone constructed from hBMP-2 gene-modified hBMSCs and HA scaffolds stably expresses and secretes active hBMP-2.
• These engineered constructs effectively promote new bone formation in vivo in nude mice.
• This approach holds significant potential for enhancing bone regeneration therapies.