The ability of drugs and therapeutic antibodies to reach central nervous system (CNS) targets is greatly diminished by the blood–brain barrier (BBB). Receptor-mediated transcytosis (RMT), which is responsible for the transport of natural protein ligands across the BBB, was identified as a way to increase drug delivery to the brain. In this study, we characterized IGF1R5, which is a single-domain antibody (sdAb) that binds to insulin-like growth factor-1 receptor (IGF1R) at the BBB, as a ligand that triggers RMT and could deliver cargo molecules that otherwise do not cross the BBB. Surface plasmon resonance binding analyses demonstrated the species cross-reactivity of IGF1R5 toward IGF1R from multiple species. To overcome the short serum half-life of sdAbs, we fused IGF1R5 to the human (hFc) or mouse Fc domain (mFc). IGF1R5 in both N- and C-terminal mFc fusion showed enhanced transmigration across a rat BBB model (SV-ARBEC) in vitro. Increased levels of hFc-IGF1R5 in the cerebrospinal fluid and vessel-depleted brain parenchyma fractions further confirmed the ability of IGF1R5 to cross the BBB in vivo. We next tested whether this carrier was able to ferry a pharmacologically active payload across the BBB by measuring the hypothermic and analgesic properties of neurotensin and galanin, respectively. The fusion of IGF1R5-hFc to neurotensin induced a dose-dependent reduction in the core temperature. The reversal of hyperalgesia by galanin that was chemically linked to IGF1R5-mFc was demonstrated using the Hargreaves model of inflammatory pain. Taken together, our results provided a proof of concept that appropriate antibodies, such as IGF1R5 against IGF1R, are suitable as RMT carriers for the delivery of therapeutic cargos for CNS applications.

Synthetic grafts have been developed for vascular bypass surgery, however, the risks of thrombosis and neointimal hyperplasia still limit their use. Tissue engineering with the use of adipose-derived stem cells (ASCs) has shown promise in addressing these limitations. Here we further characterized and optimized the ASC differentiation into smooth muscle cells (VSMCs) induced by TGF-β and BMP-4. TGF-β and BMP-4 induced a time-dependent expression of SMC markers in ASC. Shortening the differentiation period from 7 to 4 days did not impair the functional property of contraction in these cells. Stability of the process was demonstrated by switching cells to regular growth media for up to 14 days. The role of IGFBP7, a downstream effector of TGF-β, was also examined. Finally, topographic and surface patterning of a substrate is recognized as a powerful tool for regulating cell differentiation. Here we provide evidence that a non-woven PET structure does not affect the differentiation of ASC. Taken together, our results indicate that VSMCs differentiated from ASCs are a suitable candidate to populate a PET-based vascular scaffolds. By employing an autologous source of cells we provide a novel alternative to address major issues that reduces long-term patency of currently vascular grafts.

Chronic pain is a maladaptive neurological disease that remains a major global healthcare problem. Voltage-gated sodium channels (Na_vs) are major drivers of the excitability of sensory neurons, and the Na_v subtype 1.7 (Na_v1.7) has been shown to be critical for the transmission of pain-related signaling. This is highlighted by demonstrations that gain-of-function mutations in the Na_v1.7 gene SCN9A result in various pain pathologies, whereas loss-of-function mutations cause complete insensitivity to pain. A substantial body of evidence demonstrates that chronic neuropathy and inflammation result in an upregulation of Na_v1.7, suggesting that this channel contributes to pain transmission and sensation. As such, Na_v1.7 is an attractive human-validated target for the treatment of pain. Nonetheless, a lack of subtype selectivity, insufficient efficacy, and adverse reactions are some of the issues that have hindered Na_v1.7-targeted drug development. This review summarizes the pain behavior profiles mediated by Na_v1.7 reported in multiple preclinical models, outlining the current knowledge of the biophysical, physiological, and distribution properties required for a Na_v1.7 inhibitor to produce analgesia.

Editorial: Methods and applications in Alzheimer's disease and related dementias

Tissue engineering has shown great promise in generating vascular grafts with properties similar to that of native blood vessels. Vascular Smooth Muscle Cells (VSMC) are the main component of the vasculature tunica media. Recreation of this layer represents a major challenge in tissue engineering due to difficulties in harvesting and culturing autologous VSMC. The use of stem cells and their inherent ability to differentiate into diverse cell types, including vascular lineages, have been proposed

Development of therapies and pharmacological management of central nervous system diseases is significantly hampered by the presence of the highly selective blood–brain barrier (BBB). Receptor-mediated transcytosis (RMT) has proven to be a robust mechanism for delivering a wide variety of therapeutic modalities across the BBB. The present study describes the use of a neurotensin-based pharmacodynamic model to evaluate the brain penetrating capacity of FC5, a well-characterized RMT shuttle. Here we produce fusion molecules of FC5 with human Fc and neurotensin and show that intact but not C-terminally clipped neurotensin proteins containing either FC5 (FC5Fc-neurotensin) or a non-BBB-crossing control (A20.1Fc-neurotensin) retain the ability to activate neurotensin receptor type 1. In in vivo studies, intravenous administration of FC5Fc-neurotensin, but not neurotensin alone or A20.1Fc-neurotensin, induced a drop in the core body temperature in both rats and mice. We further extended these findings to non-human primates, demonstrating the ability of FC5 to cross the BBB in this species. Collectively, our results further support the potential of FC5 in delivering payloads across the BBB. The neurotensin model of hypothermia is also validated as a pharmacodynamic approach for assessing brain delivery, albeit with some necessary considerations into the molecular characterization of fusion constructs before in vivo evaluation.