Platelet‐Inspired Nanocells for Targeted Heart Repair After Ischemia/Reperfusion Injury

Cardiovascular disease is the leading cause of mortality worldwide. While reperfusion therapy is vital for patient survival post‐heart attack, it also causes further tissue injury, known as myocardial ischemia/reperfusion (I/R) injury in clinical practice. Exploring ways to attenuate I/R injury is of clinical interest for improving post‐ischemic recovery. A platelet‐inspired nanocell (PINC) that incorporates both prostaglandin E2 (PGE₂)‐modified platelet membrane and cardiac stromal cell‐secreted factors to target the heart after I/R injury is introduced. By taking advantage of the natural infarct‐homing ability of platelet membrane and the overexpression of PGE₂ receptors (EPs) in the pathological cardiac microenvironment after I/R injury, the PINCs can achieve targeted delivery of therapeutic payload to the injured heart. Furthermore, a synergistic treatment efficacy can be achieved by PINC, which combines the paracrine mechanism of cell therapy with the PGE₂/EP receptor signaling that is involved in the repair and regeneration of multiple tissues. In a mouse model of myocardial I/R injury, intravenous injection of PINCs results in augmented cardiac function and mitigated heart remodeling, which is accompanied by the increase in cycling cardiomyocytes, activation of endogenous stem/progenitor cells, and promotion of angiogenesis. This approach represents a promising therapeutic delivery platform for treating I/R injury.     

Activated Platelets‐Targeting Micelles with Controlled Drug Release for Effective Treatment of Primary and Metastatic Triple Negative Breast Cancer

The frequent relapse and metastasis characteristics of triple negative breast cancer (TNBC) make it a fraught issue with very poor prognosis in clinic. An effective treatment for TNBC should prevent and even eliminate metastasis as well as suppress primary lesion expansion. Recent progress reveals that platelets can be recruited and activated by tumor cells through intercellular adhesion molecules (ICAM), and help aggressive circulating tumor cells (CTCs) form metastasis. Therefore, activated platelets are considered with possession of tumor‐homing, CTC‐capturing, and metastasis‐targeting abilities. In this work, a P‐selectin (expressed on activated platelet surface) targeting peptide (PSN) is modified on a redox‐responsive paclitaxel‐loaded micelle (PSN‐PEG‐SS‐PTX₄ micelle) to utilize activated platelets as a “bridge” for interaction with cancer cells. The PSN‐modified micelle can easily adhere to the surface of activated platelets and subsequently capture CTCs in blood circulation. Compared to Taxol and PEG‐SS‐PTX₄ micelle, PSN‐PEG‐SS‐PTX₄ micelle also exhibits enhanced primary TNBC/metastasis targeting and penetrating effect through binding with tumor infiltrating platelets and thus significantly improves treatment outcome. More importantly, PSN‐PEG‐SS‐PTX₄ micelle potently suppressed lung metastasis of TNBC and reduced incidence of distant liver metastasis. The activated platelet‐targeting redox‐responsive micelle system provides a promising prospect for the omnidirectional treatment of metastatic cancer.     

Highly stretchable and sensitive strain sensors using nano-graphene coated natural rubber

Flexible, stretchable and wearable sensors are needed for the human motion detection. Here, a highly stretchable and sensitive strain sensor is fabricated based on the coating of nano-graphene platelets on natural rubber by simple dry coating process. The gauge factors are adjustable in the ranges of 0.78–52.53 depended on the preparation conditions and strain state. The sensors showed a high stretchability up to 750% and high durability of 1500 stretching–releasing cycles. The stretchable strain sensors are capable of detecting a bending fingers and the pulse of radial artery on the wrist. In addition, a smart glove made form five independent strain sensors was created. The data of the glove finger motions are used to control an avatar robotic hand.     

碳化硅晶片的制备技术

碳化硅晶须和晶片都是陶瓷基、金属基、树脂基复合材料的理想增强体，与碳化硅晶须相比，有关碳化硅晶片制备与应用的报道相对较少。论述了碳化硅晶片在复合材料中的应用，比较了国内外碳化硅晶片的各种制备技术。阐明了加热方式对碳化硅晶片制备的影响。指出低成本、新型热源的开发与推广应用有利于实现碳化硅晶片的规模化生产。     

Beyond Haemostasis and Thrombosis: Platelets in Depression and Its Co-Morbidities

Alongside their function in primary haemostasis and thrombo-inflammation, platelets are increasingly considered a bridge between mental, immunological and coagulation-related disorders. This review focuses on the link between platelets and the pathophysiology of major depressive disorder (MDD) and its most frequent comorbidities. Platelet- and neuron-shared proteins involved in MDD are functionally described. Platelet-related studies performed in the context of MDD, cardiovascular disease, and major neurodegenerative, neuropsychiatric and neurodevelopmental disorders are transversally presented from an epidemiological, genetic and functional point of view. To provide a complete scenario, we report the analysis of original data on the epidemiological link between platelets and depression symptoms suggesting moderating and interactive effects of sex on this association. Epidemiological and genetic studies discussed suggest that blood platelets might also be relevant biomarkers of MDD prediction and occurrence in the context of MDD comorbidities. Finally, this review has the ambition to formulate some directives and perspectives for future research on this topic.     

Graphene platelets/aluminium nitride metacomposites with double percolation property of thermal and electrical conductivity

Graphene platelets/aluminium nitride (GPLs/AlN) metacomposites with double percolation property of thermal and electrical conductivity were successfully fabricated by spark plasma sintering. Microstructures and phase composition of the GPLs/AlN metacomposites were investigated by field emission scanning electron microscopy, X-ray diffraction and Raman spectroscopy. With increase of the GPLs contents, the double percolation property of thermal (19.27?wt% GPL) and electrical conductivity (19.03?wt% GPL) was found. Moreover, the negative permittivity behavior was also observed when the GPLs content reached 19.50?wt%, which was attributed to the formation of continuous GPLs networks. Finally, the equivalent circuit models were used to analyze the negative permittivity behavior. As the reactance (Z′′) converted from negative to positive, the inductors were introduced into the equivalent circuit models, and the GPLs/AlN metacomposites went through the capacitive-inductive transition with the increasing GPLs content, corresponding to the negative permittivity behavior.     

Curcumin at Low Doses Potentiates and at High Doses Inhibits ABT-737-Induced Platelet Apoptosis

Curcumin is a natural bioactive component derived from the turmeric plant Curcuma longa, which exhibits a range of beneficial activities on human cells. Previously, an inhibitory effect of curcumin on platelets was demonstrated. However, it is unknown whether this inhibitory effect is due to platelet apoptosis or procoagulant platelet formation. In this study, curcumin did not activate caspase 3-dependent apoptosis of human platelets, but rather induced the formation of procoagulant platelets. Interestingly, curcumin at low concentration (5 µM) potentiated, and at high concentration (50 µM) inhibited ABT-737-induced platelet apoptosis, which was accompanied by inhibition of ABT-737-mediated thrombin generation. Platelet viability was not affected by curcumin at low concentration and was reduced by 17% at high concentration. Furthermore, curcumin-induced autophagy in human platelets via increased translocation of LC3I to LC3II, which was associated with activation of adenosine monophosphate (AMP) kinase and inhibition of protein kinase B activity. Because curcumin inhibits P-glycoprotein (P-gp) in cancer cells and contributes to overcoming multidrug resistance, we showed that curcumin similarly inhibited platelet P-gp activity. Our results revealed that the platelet inhibitory effect of curcumin is mediated by complex processes, including procoagulant platelet formation. Thus, curcumin may protect against or enhance caspase-dependent apoptosis in platelets under certain conditions.     

A Matter of Size and Placement: Varying the Patch Size of Anisotropic Patchy Colloids

Non-spherical colloids provided with well-defined bonding sites—often referred to as patches—are increasingly attracting the attention of materials scientists due to their ability to spontaneously assemble into tunable surface structures. The emergence of two-dimensional patterns with well-defined architectures is often controlled by the properties of the self-assembling building blocks, which can be either colloidal particles at the nano- and micro-scale or even molecules and macromolecules. In particular, the interplay between the particle shape and the patch topology gives rise to a plethora of tilings, from close-packed to porous monolayers with pores of tunable shapes and sizes. The control over the resulting surface structures is provided by the directionality of the bonding mechanism, which mostly relies on the selective nature of the patches. In the present contribution, we investigate the effect of the patch size on the assembly of a class of anisotropic patchy colloids—namely, rhombic platelets with four identical patches placed in different arrangements along the particle edges. Larger patches are expected to enhance the bond flexibility, while simultaneously reducing the bond selectivity as the single bond per patch condition—which would guarantee a straightforward mapping between local bonding arrangements and long-range pattern formation—is not always enforced. We find that the non-trivial interplay between the patch size and the patch position can either promote a parallel particle arrangement with respect to a non-parallel bonding scenario or give rise to a variety a bonded patterns, which destroy the order of the tilings. We rationalize the occurrence of these two different regimes in terms of single versus multiple bonds between pairs of particles and/or patches.     

Microelectromechanical System Measurement of Platelet Contraction: Direct Interrogation of Myosin Light Chain Phosphorylation

Myosin Light Chain (MLC) regulates platelet contraction through its phosphorylation by Myosin Light Chain Kinase (MLCK) or dephosphorylation by Myosin Light Chain Phosphatase (MLCP). The correlation between platelet contraction force and levels of MLC phosphorylation is unknown. We investigate the relationship between platelet contraction force and MLC phosphorylation using a novel microelectromechanical (MEMS) based clot contraction sensor (CCS). The MLCK and MLCP pair were interrogated by inhibitors and activators of platelet function. The CCS was fabricated from silicon using photolithography techniques and force was validated over a range of deflection for different chip spring constants. The force of platelet contraction measured by the clot contraction sensor (CCS) was compared to the degree of MLC phosphorylation by Western Blotting (WB) and ELISA. Stimulators of MLC phosphorylation produced higher contraction force, higher phosphorylated MLC signal in ELISA and higher intensity bands in WB. Inhibitors of MLC phosphorylation produced the opposite. Contraction force is linearly related to levels of phosphorylated MLC. Direct measurements of clot contractile force are possible using a MEMS sensor platform and correlate linearly with the degree of MLC phosphorylation during coagulation. Measured force represents the mechanical output of the actin/myosin motor in platelets regulated by myosin light chain phosphorylation.     

Preparation of micrometer-sized α-Al2O3 platelets by thermal decomposition of AACH

Micrometer-sized α-Al₂O₃ platelets with hexagonal shape were prepared by thermal decomposition of ammonium aluminum carbonate hydroxide (AACH) using AlF₃ as an additive. The precursor and the calcined product were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy and differential scanning calorimetry. The α-Al₂O₃ platelets with the size of 2-3 μm were obtained by calcining AACH at 1200 °C with 5 wt.% AlF₃. The morphology modification is attributed to the various growth rates along different crystal orientations due to the adsorption and uneven distribution of AlF₃. A step growth mode is responsible for the formation of the platelets.