Engineering Bioactive Nanoparticles to Rejuvenate Vascular Progenitor Cells

Introduction: Fetal exposure to gestational diabetes mellitus (GDM) predisposes children to future health complications including hypertension and cardiovascular disease. A key mechanism by which these complications occur is through stress-induced dysfunction of vascular progenitor cells, including endothelial colony-forming cells (ECFCs). In particular, overexpression of transgelin (TAGLN), also known as SM22, in GDM-ECFCs is associated with actin cytoskeletal rearrangement, which results in reduced cell migration and impaired vasculogenesis. We hypothesized that bioactive nanoparticles conjugated on the surface of GDM-ECFCs can provide a sustained pseudo-autocrine stimulation to improve in vitro and in vivo vasculogenesis.

Materials and

Methods: We designed multilamellar lipid nanoparticles with an average size of 147±63 nm in diameter to deliver small molecules SB-431542 (TGF-β inhibitor) directly to the surface of GDM-ECFCs. Cell surface engineering was used to couple bioactive NPs onto the surface of GDM-ECFCs. The ability of bioactive NPs to restore cell migration and proliferation, as well as vascular tube formation was evaluated in vitro. Through delivery of engineered cells in vivo, we assess the endothelium repair and new blood vessel formation.

Results, Conclusions, and Discussions: Bioactive nanoparticles can be robustly conjugated to the surface of ECFCs using thiol-maleimide coupling without altering cell viability and key progenitor phenotypes (Fig 1A-C). By controlling the release kinetic of TGF-β inhibitor from the nanoparticles, we can normalize TAGLN expression and improve cell migration, a critical key step in establishing functional vascular networks (Fig 1D-E). Moreover, bioactive nanoparticles can restore the vasculogenic potential of GDM-ECFCs in both 2D Matrigel and 3D collagen assays (Fig 1F-J). Finally, when transplanted into immunodeficient mice, GDM-ECFCs conjugated with bioactive nanoparticles exhibit robust de novo blood vessel formation with high engraftment rate, comparable to normal ECFCs (Fig 1K-N). Collectively, these findings highlight a simple, yet promising strategy to rejuvenate GDM-ECFCs and improve their therapeutic potentials, which can be clinically-translated to address various cardiovascular complications, as well as toward a range of approaches in tissue repair and regenerative medicine.

Acknowledgements (Optional): We acknowledge support from the University of Notre Dame through “Advancing Our Vision” Initiative in Stem Cell Research and Scientific Wellness Initiative, Harper Cancer Research Institute – American Cancer Society Institutional Research Grant (IRG-17-182-04), American Heart Association through Career Development Award (19-CDA-34630012 to D.H.-P.), and from National Institutes of Health (R01-HL-094725 to L.S.H. and R35-GM-143055 to D.H.-P.). We would like to thank the Notre Dame Integrated Imaging Facility for performing TEM imaging and the Immunohistochemistry Core Facility at the Indiana University School of Medicine for performing the IHC staining and analysis, as well as AngioBioCore at Indiana University Simon Comprehensive Cancer Center (NIDDK/NIH U54-DK-106846 and P30 CA-082709) for isolating and characterizing cord blood samples. This publication was made possible, with support from the Indiana Clinical and Translational Science Institute (I-CTSI) funded, in part by Grant Number ULITR001108 from the NIH for Advancing Translational Sciences, Clinical and Translational Science Awards.