Perfluorocarbon Nanoparticles Mediated Platelet Blocking Disrupt Vascular Barriers to Improve the Efficacy of Oxygen-Sensitive Antitumor Drugs.

Currently, limited tumor drug permeation and poor oxygen perfusion are two major bottlenecks that significantly impair the efficacy of existing antitumor drugs, especially oxygen-sensitive antitumor drugs. One vital cause of these major bottlenecks is the abnormal tumor vessel barrier. To the best knowledge of the authors, platelets play a vital role in the maintenance of an abnormal tumor blood barrier through platelet-tumor interaction. Thus, platelet inhibition may present a new way to enhance drug delivery. In this study, it is originally discovered that perfluorotributylamine-based albumin nanoparticles (PFTBA@HSA) possess excellent platelet inhibiting abilities, which then selectively disrupt the tumor vessel barrier, resulting in a remarkably enhanced intratumoral drug accumulation. Interestingly enough, the tumor hypoxia is also obviously relieved by enhanced oxygen carrier red blood cell distribution and PFTBA@HSA infiltration in the tumors. Finally, the efficacy of oxygen-sensitive antitumor drugs is significantly amplified by PFTBA@HSA owing to enhanced drug permeation and relieved tumor hypoxia. Therefore, for the first time, it is demonstrated that PFTBA@HSA could be used as an effective way to improve the efficacy of existing tumor therapies by disrupting tumor vessel barriers through targeted platelet inhibition.

Utility of microfluidic devices to study the platelet-endothelium interface.

The integration of biomaterials and understanding of vascular biology has led to the development of perfusable endothelialized flow models, which have been used as valuable tools to study the platelet-endothelium interface under shear. In these models, the parameters of geometry, compliance, biorheology, and cellular complexity are varied to recapitulate the physical biology of platelet recruitment and activation under physiologically relevant conditions of blood flow. In this review, we summarize the mechanistic insights learned from perfusable microvessel models and discuss the potential utility as well as challenges of endothelialized microfluidic devices to study platelet function in the bloodstream in vitro.

Probing cerebral malaria inflammation in 3D human brain microvessels.

Sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the brain microcirculation is a hallmark of cerebral malaria (CM), which leads to endothelial activation, brain swelling, and death. Here, we probed CM inflammation in a perfusable 3D human brain microvessel model. 3D brain microvessels supported in vivo-like capacities for parasite binding and maturation in situ, leading to a distinct inflammatory response from the pro-inflammatory cytokine tumor necrosis factor α (TNF-α). By combining transcriptional analysis, imaging, and leukocyte perfusion, we showed that whereas TNF-α promotes a reversible inflammatory phenotype with widespread leukocyte recruitment, parasites induce unique stress response pathways and cause localized cell adhesivity changes, focal endothelial disruptions, and apoptosis. Furthermore, parasites modified the temporal kinetics of the TNF transcriptional response, suggesting augmented inflammatory damage with the two sequential stimuli. Our findings offer mechanistic insights into CM biology in a 3D brain microvessel mimetic platform and suggest that multiple events intersect to promote brain barrier inflammation in CM.