External carotid artery-radial artery-vertebral artery bypass for surgical treatment of radiculopathy caused by an extracranial vertebral artery aneurysm: A case report and review of the literature.

Background: Vertebral artery (VA) aneurysm is a rare etiology of cervical radiculopathy and there is a paucity of case reports described in the literature. Case Description: We describe a case of a patient with no history of trauma presenting with a large right VA aneurysm at the C5-C6 level compressing the C6 nerve root and causing a painful radiculopathy. The patient underwent successful external carotid artery-radial artery-VA bypass followed by trapping of the aneurysm and decompression of the C6 nerve root. Conclusion: VA bypass is an effective tool for treatment of symptomatic large extracranial VA aneurysms and a rare cause of radiculopathy.

A bioactive material with dual integrin-targeting ligands regulates specific endogenous cell adhesion and promotes vascularized bone regeneration in adult and fetal bone defects.

Significant progress has been made in designing bone materials capable of directing endogenous cells to promote vascularized bone regeneration. However, current strategies lack regulation of the specific endogenous cell populations for vascularized bone regeneration, thus leading to adverse tissue formation and decreased regenerative efficiency. Here, we engineered a biomaterial to regulate endogenous cell adhesion and promote vascularized bone regeneration. The biomaterial works by presenting two synthetic ligands, LLP2A and LXW7, explicitly targeting integrins α4ß1 and αvß3, respectively, expressed on the surfaces of the cells related to bone formation and vascularization, such as mesenchymal stem cells (MSCs), osteoblasts, endothelial progenitor cells (EPCs), and endothelial cells (ECs). In vitro, the LLP2A/LXW7 modified biomaterial improved the adhesion of MSCs, osteoblasts, EPCs, and ECs via integrin α4ß1 and αvß3, respectively. In an adult rat calvarial bone defect model, the LLP2A/LXW7 modified biomaterial enhanced bone formation and vascularization by synergistically regulating endogenous cells with osteogenic and angiogenic potentials, such as DLX5+ cells, osteocalcin+ cells, CD34+/CD45- cells and CD31+ cells. In a fetal sheep spinal bone defect model, the LLP2A/LXW7 modified biomaterial augmented bone formation and vascularization without any adverse effects. This innovative biomaterial offers an off-the-shelf, easy-to-use, and biologically safe product suitable for vascularized bone regeneration in both fetal and adult disease environments.