Engineering vascularized tissue is crucial for its successful implantation, survival, and integration with the host tissue. Vascular smooth muscle cells (v-SMCs) provide physical support to the vasculature and aid in maintaining endothelial viability. In this study, we show an efficient derivation of v-SMCs from human embryonic stem cells (hESCs), and demonstrate their functionality and ability to support the vasculature in vitro. Human ESCs were differentiated in monolayers and supplemented with platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-beta 1 (TGF-beta1). Human ESC-derived smooth-muscle-like cells (SMLCs) were found to highly express specific smooth muscle cell (SMC) markers--including alpha-smooth muscle actin, calponin, SM22, and smooth muscle myosin heavy chain--to produce and secrete fibronectin and collagen, and to contract in response to carbachol. In vitro tubulogenesis assays revealed that these hESC-derived SMLCs interacted with human endothelial progenitor cell (EPCs) to form longer and thicker cord-like structures in vitro. We have demonstrated a simple protocol for the efficient derivation of highly purified SMLCs from hESCs. These in vitro functional SMLCs interacted with EPCs to support and augment capillary-like structures (CLSs), demonstrating the potential of hESCs as a cell source for therapeutic vascular tissue engineering.

Approximately three million procedures annually are required to meet the surgical needs of refugees, IDPs, and asylum seekers. Most displaced persons are hosted in countries with inadequate surgical care capacity. These figures should be considered when planning humanitarian assistance and targeted surgical capacity improvements.

Entrapment and fracture of carotid angioplasty and stenting hardware is a rare complication of percutaneous stenting procedures. We describe a case of a retained distal filter embolic protection device and guidewire in a 57-year-old male in Beijing, China. After unsuccessful attempts at removal via interventional methods, a second stent was deployed to secure the original hardware in situ, and the patient was discharged. He later experienced guidewire fragmentation in the carotid artery and aortic arch, with subsequent thrombus formation. We report partial removal of the guidewire and stent via carotid artery cutdown and open thoracotomy without complication. When efforts to retrieve stenting hardware are unsuccessful, it is never a suitable choice to leave them within the artery. We advocate for early surgical management of retained materials after unsuccessful carotid artery stenting. Furthermore, improved quality monitoring and assurance programs are needed to prevent such complications in the future.