SDF-1\u03b1 gene-activated collagen scaffold enhances provasculogenic response in a coculture of human endothelial cells with human adipose-derived stromal cells

Ashang L Laiva,Michael B Keogh,Fergal J O’Brien

doi:10.1007/s10856-021-06499-6

Abstract

Novel biomaterials can be used to provide a better environment for cross talk between vessel forming endothelial cells and wound healing instructor stem cells for tissue regeneration. This study seeks to investigate if a collagen scaffold containing a proangiogenic gene encoding for the chemokine stromal-derived factor-1 alpha (SDF-1α GAS) could be used to enhance functional responses in a coculture of human umbilical vein endothelial cells (HUVECs) and human adipose-derived stem/stromal cells (ADSCs). Functional responses were determined by (1) monitoring the amount of junctional adhesion molecule VE-cadherin released during 14 days culture, (2) expression of provasculogenic genes on the 14th day, and (3) the bioactivity of secreted factors on neurogenic human Schwann cells. When we compared our SDF-1α GAS with a gene-free scaffold, the results showed positive proangiogenic determination characterized by a transient yet controlled release of the VE-cadherin. On the 14th day, the coculture on the SDF-1α GAS showed enhanced maturation than its gene-free equivalent through the elevation of provasculogenic genes (SDF-1α—7.4-fold, CXCR4—1.5-fold, eNOS—1.5-fold). Furthermore, we also found that the coculture on SDF-1α GAS secretes bioactive factors that significantly (p < 0.01) enhanced human Schwann cells’ clustering to develop toward Bünger band-like structures. Conclusively, this study reports that SDF-1α GAS could be used to produce a bioactive vascularized construct through the enhancement of the cooperative effects between endothelial cells and ADSCs.

Highlights

Insufficient regeneration of a vascular network remains one of the major limitations of biomaterials scaffolds used in wound healing [1]
MTS assay showed that at days 3 and 7, human umbilical vein endothelial cells (HUVECs) transfected with PEI–pSDF-1α significantly promoted their survivability than the groups transfected with polyplex carrying the nontherapeutic gene, pDNA encoding a nontherapeutic Gaussia luciferase (pLuc) (Fig. 1A)
A preliminary 2D study showed that the HUVECs transfected with PEI–pSDF-1α polyplex transiently secreted SDF-1α proteins that actively recruited adipose-derived stem/ stromal cells (ADSCs) and enhanced their adhesion to the HUVECs

Summary

Introduction

Insufficient regeneration of a vascular network remains one of the major limitations of biomaterials scaffolds used in wound healing [1] To overcome this problem, functionalizing the scaffolds with either natural or synthetic proangiogenic growth factors to promote local angiogenesis is a popular strategy [2,3,4,5]. These angiogenic factors are susceptible to proteolysis, while bolus delivery of high doses to sustain the therapeutic effect raises the risk of toxicity as well as cost [7] Parallel investigations such as prevascularizing biomaterial scaffolds using endothelial cells show potential [8,9,10]. Strategies aiming at improving the stability of the endothelial network while allowing adequate angiogenesis continues to be investigated [13, 14]

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