Lead
Uncontrolled expression of Vascular Endothelial Growth Factor (VEGF) can induce aberrant angiogenesis. We developed a method to ensure sustained but controlled VEGF release by FACS-based purification of transduced adipose tissue-derived mesenchymal stromal cells (ASC).In this study we aim to combine cell-based gene therapy with tissue engineering to generate ASC-based patches capable to promote normal and efficient angiogenesis in the surrounding area..

Lay summary

Title: Engineering of a cell-loaded patch as a controlled VEGF-releasing device to treat cardiac ischemia

Background

Uncontrolled expression of VEGF can induce aberrant angiogenesis. We developed a method to ensure sustained but controlled VEGF release by FACS-based purification of transduced adipose tissue-derived mesenchymal stromal cells (ASC), which could already induce effective vascularization when injected in ischemic myocardium despite the poor cell survival.

In this study we aim to combine cell-based gene therapy with tissue engineering to generate ASC-based patches capable to promote normal and efficient angiogenesis in the surrounding area.

Specific Aims

1. Obtain the proof of principle that VEGF-expressing ASC can reliably induce normal angiogenesis inside and around the engineered patch.        

2. Investigate the role of fresh stromal vascular fraction (SVF) derived cells, as source of endothelial progenitors and pericytic origin cells, in the patch vascularization dynamics and in the stabilization of the vascular networks when co-cultured with ASC expressing either controlled or heterogeneous VEGF levels.

Methods

ASC were transduced with retroviral vectors expressing VEGF164 linked to a FACS-quantifiable cell surface marker (truncated CD8) and a population homogeneously expressing a defined VEGF level (VEGF) was FACS-purified. Patches were generated by culturing cells for 5 days on collagen scaffolds in a perfusion-based bioreactor. Their extrinsic angiogenic potential will be assessed in both subcutaneous and ischemic myocardial nude rat models.

 

Potential significance of the results

The proposed project is expected to provide (1) a basic proof-of-principle to use a cell-based angiogenic factor release system for promoting vascularization, (2) insights of the angiogenic dynamics in vivo and will elucidate the role of SVF in the vascularization process.