Engineered Human Adipose-Derived Stem Cells Inducing Endothelial Lineage and Angiogenic Response

Abstract

Biotechnological interventions to engineer favorable biochemical environments that facilitate wound repair through quick attainment of vasculature are of immense demand. Potential of angiogenic factors (AF), notably vascular endothelial growth factor A (VEGF-A) and hypoxia-inducible factor-1α (HIF-1α) and the paracrine role of human adipose-derived mesenchymal stromal cells (hADMSCs) in establishing vasculature has been reported. Independent application of AF or hADMSCs has led to clinical failure, pertaining to poor means of delivery, deprived bioavailability, and insufficiency to drive adequate angiogenesis, respectively. Although augmenting well-timed release of AF through bioengineered hADMSCs seems appealing, effective nonviral transfection in primary hADMSCs continue to be underexplored in the context of quick reproducibility and translational safety. Based on high safety and clinical value, Neon^® Transfection System in primary hADMSCs transfection was explored in this study. Multiple donor cell experiments established ∼50% transfection efficiency, acceptable cell viability, and posttransfection phenotype maintenance with safe and transient AF delivery. The delivered AF induced endothelial lineage commitment of engineered/nonengineered heterogeneous hADMSCs in culture. Delivered AF was established to function in a dose-dependent manner in terms of effect on human umbilical vein endothelial cell proliferation, migration, tube elongation, and elevated Flk-1 expression, emphasizing combinatorial AF therapy to be superior. This in vitro study is the first to report Neon Transfection System for reproducible bioengineering of primary hADMSCs for functional AF (VEGF-A & HIF-1α) delivery, demonstrating endothelial lineage commitment, predicting combinatorial effectiveness and translational safety for subsequent regenerative medicine application.

Impact Statement

With respect to the persistent hunt for a cytocompatible, translational, reproducible, and effective approach in engineering primary human adipose-derived mesenchymal stromal cells (hADMSCs), we demonstrate the application of Neon^® Transfection System in adequate transient delivery of angiogenic factors. The study presents functional assessment of this approach in vitro, with two notable outcomes at translational perspective; (1) Bioengineered hADMSCs secretome does induce endothelial lineage commitment of stem cells at both transcriptional and translational levels and (2) Combinatorial delivery of vascular endothelial growth factor A and hypoxia-inducible factor-1α by bioengineered hADMSCs enhance upregulation of endothelial cell proliferation, migration-associated wound closure, and endothelial tube formation with augmented Flk-1 expression, as compared with their independent actions. The methods described in this study paves way for in vivo evaluation on identification of appropriate chronic wound models and subsequently for clinical translation. The technology developed also has application in vascularization of tissue-engineered constructs.