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The control paradigm of small vessel pathophysiology has changed to focus on the vascular out‐wall rather than the lumen‐intimal factors. As an emerging controller of the external wall, the microvasculature ("vasa vasorum") provides interactional routes between the in‐and out‐sides of the vascular wall. Despite numerous approaches to developing small‐diameter vascular grafts, engineering artificial vasa vasorum (AVV) has not been projected as a multi‐functional solution to address long‐standing issues such as thrombotic and immune controls for wall regeneration. Here, the AVV is engineered using a microchannel network hydrogel after a multi‐study validation of implantation functions and then used to wrap the external wall of the cell‐free vessel post‐decellularization while preserving its mechanical properties. Upon inter‐positional and bypass grafting to rabbit arteries, the AVV graft facilitates the recruitment of vascular cells into the cell‐free wall by promoting invasion of angiogenic and vasculogenic cells through the microchannel‐mediated M2 polarization of macrophages. This function results in the efficient restoration of smooth muscle cells, and the revitalized vascular elasticity helps to maintain long‐term patency. The AVV, therefore, serves as an effective catalyst for vascular wall regeneration, offering a solution to clinically successful small‐diameter vascular grafting. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma frequently recurs after surgery, necessitating personalized clinical approaches based on tumor avatar models. However, location-dependent oxygen concentrations resulting from the dual hepatic vascular supply drive the inherent heterogeneity of the tumor microenvironment, which presents challenges in developing an avatar model. In this study, tissue samples from 12 patients with hepatocellular carcinoma are cultured directly on a chip and separated based on preference of oxygen concentration. Establishing a dual gradient system with drug perfusion perpendicular to the oxygen gradient enables the simultaneous separation of cells and evaluation of drug responsiveness. The results are further cross-validated by implanting the chips into mice at various oxygen levels using a patient-derived xenograft model. Hepatocellular carcinoma cells exposed to hypoxia exhibit invasive and recurrent characteristics that mirror clinical outcomes. This chip provides valuable insights into treatment prognosis by identifying the dominant hepatocellular carcinoma type in each patient, potentially guiding personalized therapeutic interventions. Hepatocellular carcinoma is the most common type of primary liver cancer. Here the authors show an oxygen gradient chip that separates aggressive hepatocellular carcinoma cells from a heterogeneous tumor mass, mirroring the conditions of the portal vein, hepatic artery, and liver. [ABSTRACT FROM AUTHOR]

Clinical translation of nanoparticles is limited because of their short circulation time, which hampers targeting to prolong therapeutic effects. Angiogenesis is required to regenerate damaged sites under inflammation, and CD11b+ cells turn vasculogenic under hypoxia. As a turning‐point strategy to increase the circulation time, this study explores liposomal targeting of splenic CD11b+ cells, which are gathered in the spleen and move to inflamed sites inherently. Moreover, nano‐hypoxia is strategized as a therapeutic method by loading liposomes with a hypoxic‐mimetic agent (CoCl2) to induce in situ reprogramming of splenic CD11b+ cells upon venous injection. Consequently, the vasculogenic potential of reprogrammed cells accelerates regeneration through inflammation‐responsive homing. Hydrophilic coating of liposomes improves the selectivity of splenic targeting in contrast to fast targeting without coating. Hypoxia chambers and surgical induction of splenic hypoxia are compared to validate the reprogramming effect. The strategy is validated in mouse models of inflamed skin, ischemic hindlimbs, and 70% hepatectomy compared with a conventional approach using bone marrow cells. Intravital multiphoton microscopy, 19F 2D/3D MRI, and microchannel hydrogel chips for 3D tissue culture are used as advanced tools. Overall, nanocarrier change to CD11b+ cells prolong targeting by inducing in situ reprogramming for inflammation‐responsive vasculogenic therapy. [ABSTRACT FROM AUTHOR]

Background: Isolated true aneurysms in the superficial femoral artery (SFA) have rarely been reported. Most cases are undiagnosed until rupture or the occurrence of complications., Case Summary: A 36-year-old woman presented with a palpable, pulsating mass on her right thigh which had increased in size over 2 months. She also had a swollen right leg and mild claudication (Stage II in Rutherford classification). For 2 months, the patient was treated by manual massage, acupuncture, and extracorporeal shock wave therapy in local clinics. Bed-side ultrasonography identified a 3.4-cm sized true aneurysm of the right SFA. There were no other aneurysms in arteries from head to toe. There was no evidence of atherosclerotic risk factors or connective tissue disease. The patient was successfully treated by a covered stent graft implantation without any complications., Discussion: Isolated true aneurysm in the SFA is rare and tends to go undiagnosed especially in young women. Ultrasonography is an easy and useful diagnostic tool for differential diagnosis of thigh mass. In this case, endovascular treatment was safely applied for a true aneurysm without rupture., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)