Approaches to improve angiogenesis in tissue-engineered skin

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Clinical failure of tissue-engineered skin grafts is often caused by delayed vascularization.
• Effective angiogenesis is essential for the survival and integration of engineered tissues.

Purpose of the Study:

• To investigate simple strategies for improving angiogenesis and vascularization in a tissue-engineered skin model.
• To identify key factors influencing endothelial cell penetration into engineered dermal matrices.

Main Methods:

• Utilized a modified Guirguis chamber to test multiple variables simultaneously within the same human dermis.
• Assessed endothelial cell (small vessel human dermal microvascular endothelial cells) penetration using a qualitative scoring system.
• Examined the effects of cell type, growth factors, co-cultured cells (keratinocytes, fibroblasts), mechanical penetration, addition site, and hypoxia.

Main Results:

• Endothelial cell penetration was not improved by adding angiogenic growth factors (VEGF, bFGF), keratinocytes, fibroblasts, or mechanical perforation.
• A minimum cell seeding density was identified for effective penetration.
• Hypoxia and addition of endothelial cells to the papillary surface significantly enhanced dermal penetration.

Conclusions:

• This tissue-engineered skin model is valuable for understanding vascularization mechanisms.
• Hypoxia and strategic endothelial cell placement are key factors for promoting angiogenesis in engineered skin grafts.
• Findings provide insights for improving the clinical viability of tissue-engineered skin substitutes.