Clinical implementation of endochondral bone regeneration (EBR) would benefit from the engineering of devitalized cartilaginous constructs of allogeneic origins. Nevertheless, development of effective devitalization strategies that preserves extracellular matrix (ECM) is still challenging. The aim of this study is to investigate EBR induced by devitalized, soft callus‐mimetic spheroids. To challenge the translatability of this approach, the constructs are generated using an allogeneic cell source. Neo‐bone formation is evaluated in an immunocompetent rat model, subcutaneously and in a critical size femur defect. Living spheroids are used as controls. Also, the effect of spheroid maturation towards hypertrophy is evaluated. The devitalization procedure successfully induces cell death without affecting ECM composition or bioactivity. In vivo, a larger amount of neo‐bone formation is observed for the devitalized chondrogenic group both ectopically and orthotopically. In the femur defect, accelerated bone regeneration is observed in the devitalized chondrogenic group, where defect bridging is observed 4 weeks post‐implantation. The authors' results show, for the first time, a dramatic increase in the rate of bone formation induced by devitalized soft callus‐mimetics. These findings pave the way for the development of a new generation of allogeneic, “off‐the‐shelf” products for EBR, which are suitable for the treatment of every patient.

Human immunodeficiency virus (HIV) affects millions of people globally. The associated stigma remains a challenge for individuals living with HIV and children and adolescents face the additional challenge of withstanding the peer, pubertal and identity challenges associated with growing up. The current systematic review aimed to define and explore the major stigma-related challenges of children and adolescents from their own perspectives. A secondary aim was to identify any challenges distinct to childhood and adolescence. Studies included individuals aged 3 to 18 years who were aware of their status. Fifteen studies met inclusion criteria. Narrative synthesis was conducted on the included studies. Five analytic themes emerged describing major stigma-related challenges: disclosure-related anxiety, medication adherence, feelings of abnormality, mental health issues and social exclusion. Disclosure-related anxiety and feelings of abnormality appeared to be largely confined to the experience of children and adolescents. Many of the themes centred around peer influence, highlighting the need to belong in youth. Results suggest that youth require tailored interventions targeting their age-specific challenges.

Short-term limb immobilization results in skeletal muscle decline, but the underlying mechanisms are incompletely understood. This study aimed to determine the neurophysiologic basis of immobilization-induced skeletal muscle decline, and whether repetitive Transcranial Magnetic Stimulation (rTMS) could prevent any decline. Twenty-four healthy young males (20 ± 0.5 years) underwent unilateral limb immobilization for 72 h. Subjects were randomized between daily rTMS (n = 12) using six 20 Hz pulse trains of 1.5 s duration with a 60 s inter-train-interval delivered at 90% resting Motor Threshold (rMT), or Sham rTMS (n = 12) throughout immobilization. Maximal grip strength, EMG activity, arm volume, and composition were determined at 0 and 72 h. Motor Evoked Potentials (MEPs) were determined daily throughout immobilization to index motor excitability. Immobilization induced a significant reduction in motor excitability across time (−30% at 72 h; p < 0.05). The rTMS intervention increased motor excitability at 0 h (+13%, p < 0.05). Despite daily rTMS treatment, there was still a significant reduction in motor excitability (−33% at 72 h, p < 0.05), loss in EMG activity (−23.5% at 72 h; p < 0.05), and a loss of maximal grip strength (−22%, p < 0.001) after immobilization. Interestingly, the increase in biceps (Sham vs. rTMS) (+0.8 vs. +0.1 mm, p < 0.01) and posterior forearm (+0.3 vs. +0.0 mm, p < 0.05) skinfold thickness with immobilization in Sham treatment was not observed following rTMS treatment. Reduced MEPs drive the loss of strength with immobilization. Repetitive Transcranial Magnetic Stimulation cannot prevent this loss of strength but further investigation and optimization of neuroplasticity protocols may have therapeutic benefit.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Its incidence is increasing, and is closely related to advanced liver disease. Interactions in the HCC microenvironment between tumor cells and the associated stroma actively regulate tumor initiation, progression, metastasis, and therapy response. In the present study, we used the OrganoPlate graft to establish a co-culture system consisting of dissociated HCC tumors (HCC 1-8) and cell lines, HCC derived fibroblasts and vasculature. Cultures were prepared and validated by assessing their response to Sorafenib and Lenvatinib (72 hours). Cultures had their viability (alamar blue assay), and chemokine/cytokine levels in the supernatant (Luminex) determined. In addition, the organization of the vasculature in the tumor compartment was studied through immunostainings, confocal imaging, and subsequent morphological analyses. HCC models were characterized by a range of specific markers, tumor (albumin), endothelial (CD31 and VE-Cadherin) and stromal (aSMA) cells. CD31 immunostained cultures were imaged, and morphology changes quantified. Sorafenib and Lenvatinib induced changes in the tumor vasculature area and organization. Hereby, we present vascularized patient-derived HCC models that include relevant cellular players of the HCC microenvironment. These co-cultures are highly suitable for studying specific cell types as well as patient-specific responses. We envision that this patient derived model will evolve to become a platform for understanding the interplay between angiogenesis, stroma and immune infiltrate in HCC. Citation Format: Orsola Mocellin, Abbie Robinson, Aleksandra Olczyk, Stephane Treillard, Thomas Olivier, Chee Ng, Jeroen Heijmans, Désiréé Goubert, Arthur Stok, Gilles van Tienderen, Monique Verstegen, Sebastian Trietsch, Henriëtte Lanz, Paul Vulto, Jos Joore, Karla S. Queiroz. Sorafenib and Lenvatinib induce vascular responses in patient derived HCC on-Chip models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5876.