Search

Pericytes are essential components of small blood vessels and are found in human aortic vasa vasorum. Prior work uncovered lower vasa vasorum density and decreased levels of pro‐angiogenic growth factors in adventitial specimens of human ascending thoracic aortic aneurysm. We hypothesized that adventitial extracellular matrix (ECM) from normal aorta promotes pericyte function by increasing pericyte contractile function through mechanisms deficient in ECM derived from aneurysmal aortic adventitia. ECM biomaterials were prepared as lyophilized particulates from decellularized adventitial specimens of human and porcine aorta. Immortalized human aortic adventitia‐derived pericytes were cultured within Type I collagen gels in the presence or absence of human or porcine adventitial ECMs. Cell contractility index was quantified by measuring the gel area immediately following gelation and after 48 h of culture. Normal human and porcine adventitial ECM increased contractility of pericytes when compared with pericytes cultured in absence of adventitial ECM. In contrast, aneurysm‐derived human adventitial ECM failed to promote pericyte contractility. Pharmacological inhibition of TGFβR1 and antibody blockade of α2β1 integrin independently decreased porcine adventitial ECM‐induced pericyte contractility. By increasing pericyte contractility, adventitial ECM may improve microvascular function and thus represents a candidate biomaterial for less invasive and preventative treatment of human ascending aortic disease. [ABSTRACT FROM AUTHOR]

Biodegradable synthetic elastomers with tunable mechanical and physicochemical properties remain attractive materials for soft tissue engineering. We have recently synthesized novel poly(1,3-diamino-2-hydroxypropane- co-glycerol sebacate)- co-poly(ethylene glycol) (APS- co-PEG) biodegradable elastomers. This class of PEGylated elastomers has widely tunable mechanical and degradation properties compared wtih currently available biodegradable elastomers. To further investigate the biological application of this class of elastomers, we fabricated hybrid APS- co-PEG/polycaprolactone (PCL) porous scaffolds by electrospinning. The fiber morphology, chemical composition, mechanical properties, degradability, and cytocompatibility of hybrid APS -co-PEG/PCL electrospun scaffolds were characterized. These scaffolds exhibited a wide range of mechanical properties and similar cytocompatibility to PCL scaffolds. Importantly, PEGylation inhibited platelet adhesion on all APS -co-PEG/PCL electrospun scaffolds when compared with PCL and APS/PCL scaffolds, suggesting a potential role in mitigating thrombogenicity in vivo. Additionally, APS- 25PEG/PCL scaffolds were found to be mechanically analogous to human heart valve leaflet and supported attachment of human aortic valve cells. These results reveal that hybrid APS- co-PEG/PCL scaffolds may serve as promising constructs for soft tissue engineering, especially heart valve tissue engineering. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The article examines the effect of vascular endothelial growth factor (VEGF) stimulation and blocking VEGF with soluble Flt-1 on chondrogenesis using muscle-derived stem cells (MDSCs) from mouse skeletal muscle. The study tested first the direct effect of VEGF in vitro chondrogenic ability of mouse MDSCs followed by various steps which analyze cartilage formations. The conclusion indicates the significant role of VEGF on soluble Flt-1 gene therapy uisng MDSCs.