Human three-dimensional fibroblast cultures express angiogenic activity

Area of Science:

• Tissue Engineering
• Angiogenesis Research
• Biomaterials Science

Background:

• Three-dimensional (3D) tissue constructs are essential for mimicking native tissue environments.
• Understanding growth factor expression in engineered tissues is key to their functionality.
• Vascular endothelial growth factor (VEGF) is a critical regulator of angiogenesis.

Purpose of the Study:

• To compare the angiogenic potential of 3D dermal equivalent tissues with traditional 2D fibroblast cultures.
• To investigate the role of VEGF and other growth factors in 3D engineered dermal tissue.
• To assess the functional angiogenic activity of conditioned media from these cultures.

Main Methods:

• Culturing human neonatal fibroblasts on lactate-glycollate copolymer scaffolds to create 3D dermal equivalents.
• Quantifying VEGF and Hepatocyte Growth Factor (HGF) mRNA and protein levels using RT-PCR and ELISA.
• Assessing angiogenic activity via endothelial cell proliferation, integrin expression, and the chorioallantoic membrane (CAM) assay.
• Utilizing VEGF-neutralizing and anti-HGF antibodies to determine factor specificity.

Main Results:

• 3D dermal equivalent cultures exhibited a 22-fold increase in VEGF mRNA compared to 2D monolayer cultures.
• VEGF protein was secreted in significant amounts, while HGF showed no induction.
• Conditioned media from 3D cultures potently stimulated endothelial cell proliferation and integrin expression.
• The CAM assay demonstrated a 2.8-fold increase in blood vessel production by 3D cultures, inhibited by anti-VEGF but not anti-HGF antibodies.

Conclusions:

• 3D dermal equivalent tissue significantly enhances angiogenic factor expression and activity compared to 2D cultures.
• VEGF is a primary mediator of the observed angiogenic potential in these 3D constructs.
• These findings highlight the superior capacity of 3D engineered tissues for promoting vascularization.