Functions and mechanisms of chemokine receptor 7 in tumors of the digestive system

Chemokine(C-X-C motif)receptor 7(CXCR7),recently termed ACKR3,belongs to the G protein-coupled cell surface receptor family,binds to stromal cellderived factor-1[SDF-1,or chemokine(C-X-C motif)ligand 12]or chemokine(CX-C motif)ligand 11,and is the most common chemokine receptor expressed in a variety of cancer cells.SDF-1 binds to its receptor chemokine(C-X-C motif)receptor 4(CXCR4)and regulates cell proliferation,survival,angiogenesis and migration.In recent years,another new receptor for SDF-1,CXCR7,has been discovered,and CXCR7 has also been found to be expressed in a variety of tumor cells and tumor-related vascular endothelial cells.Many studies have shown that CXCR7 can promote the growth and metastasis of a variety of malignant tumor cells.Unlike CXCR4,CXCR7 exhibits a slight modification in the DRYLAIV motif and does not induce intracellular Ca^2+release following ligand binding,which is essential for recruiting and activating G proteins.CXCR7 is generally thought to work in three ways:(1)Recruitingβ-arrestin 2;(2)Heterodimerizing with CXCR4;and(3)Acting as a“scavenger”of SDF-1,thus lowering the level of SDF-1 to weaken the activity of CXCR4.In the present review,the expression and role of CXCR7,as well as its prognosis in cancers of the digestive system,were investigated.

Neuron devices:emerging prospects in neural interfaces and recognition

Neuron interface devices can be used to explore the relationships between neuron firing and synaptic transmission,as well as to diagnose and treat neurological disorders,such as epilepsy and Alzheimer’s disease.It is crucial to exploit neuron devices with high sensitivity,high biocompatibility,multifunctional integration and high-speed data processing.During the past decades,researchers have made significant progress in neural electrodes,artificial sensory neuron devices,and neuromorphic optic neuron devices.The main part of the review is divided into two sections,providing an overview of recently developed neuron interface devices for recording electrophysiological signals,as well as applications in neuromodulation,simulating the human sensory system,and achieving memory and recognition.We mainly discussed the development,characteristics,functional mechanisms,and applications of neuron devices and elucidated several key points for clinical translation.The present review highlights the advances in neuron devices on brain-computer interfaces and neuroscience research.

Electronic structures and NIR-II optical properties of black phosphorus using first principles

Near infrared-II(NIR-II, 1 000-1 700 nm) imaging with high penetration tissue depth and signal-noise ratio has attracted wide interest in biomedicine. As a two-dimensional(2D) material with narrow band gap, the band structure of layered black phosphorus, as an important characteristic of electronic structure, determines the electronic transport and infrared optical properties, which show great potential in NIIR-II imaging. Here, the electronic structure and NIR-II optical properties of black phosphorus have been investigated in detail by employing the generalized gradient approximation + U(GGA+U) correction based on density functional theory(DFT). First, we performed the band structure and density of states for different layers of black phosphorus. From the electronic structures, the location of valence band maximum didn’t shift obviously, and the position of conduction band minimum shifted downward gradually, inducing the band gaps decreased gradually with the increasing layer number. While the layer number increased to 5, the behaviour of electronic structure was very similar to that of the bulk black phosphorus. Then, we calculated the NIR-II optical properties, and found the optical band gap of black phosphorus also showed layer dependent properties. From a single layer to 5 layers, the optical band gap changed from 1.71 e V to 0.92 e V. It is noting that black phosphorus also showed the significant optical absorption in NIR-IIa(1 300-1 400 nm) and NIR-IIb(1 500-1 700 nm) windows. Especially, the NIR-II optical absorption can be enhanced with increasing the layer number to 5, indicating promising photoresponse materials in NIR-II imaging.

Integrated printed BDNF/collagen/chitosan scaffolds with low temperature extrusion 3D printer accelerated neural regeneration after spinal cord injury

Recent studies have shown that 3D printed scaffolds integrated with growth factors can guide the growth of neurites and promote axon regeneration at the injury site.However,heat,organic solvents or cross-linking agents used in conventional 3D printing reduce the biological activity of growth factors.Low temperature 3D printing can incorporate growth factors into the scaffold and maintain their biological activity.In this study,we developed a collagen/chitosan scaffold integrated with brain-derived neurotrophic factor(3D-CC-BDNF)by low temperature extrusion 3D printing as a new type of artificial controlled release system,which could prolong the release of BDNF for the treatment of spinal cord injury(SCI).Eight weeks after the implantation of scaffolds in the transected lesion of T10 of the spinal cord,3D-CC-BDNF significantly ameliorate locomotor function of the rats.Consistent with the recovery of locomotor function,3D-CC-BDNF treatment could fill the gap,facilitate nerve fiber regeneration,accelerate the establishment of synaptic connections and enhance remyelination at the injury site.

Functional micro/nanobubbles for ultrasound medicine and visualizable guidance

Chemically functionalized gas-filled bubbles with a versatile micro/nano-sized scale have witnessed a long history of developments and emerging applications in disease diagnosis and treatments.In combination with ultrasound and image-guidance,micro/nanobubbles have been endowed with the capabilities of biomedical imaging,drug delivery,gene transfection and diseaseoriented therapy.As an external stimulus,ultrasound(US)-mediated targeting treatments have been achieving unprecedented efficiency.Nowadays,US is playing a crucial role in visualizing biological/pathological changes in lives as a reliable imaging technique and a powerful therapeutic tool.This review retrospects the history of ultrasound,the chemistry of functionalized agents and summarizes recent advancements of functional micro/nanobubbles as US contrast agents in preclinical and transclinical research.Latest ultrasound-based treatment modalities in association with functional micro/nanobubbles have been highlighted as their great potentials for disease precision therapy.It is believed that these state-of-the-art micro/nanobubbles will become a booster for ultrasound medicine and visualizable guidance to serve future human healthcare in a more comprehensive and practical manner.

Transformer-based ensemble deep learning model for EEG-based emotion recognition

Emotion recognition is one of the most important research directions in the field of brain–computer interface(BCI).However,to conduct electroencephalogram(EEG)-based emotion recognition,there exist difficulties regarding EEG signal processing;moreover,the performance of classification models in this regard is restricted.To counter these issues,the 2022 World Robot Contest successfully held an affective BCI competition,thus promoting the innovation of EEG-based emotion recognition.In this paper,we propose the Transformer-based ensemble(TBEM)deep learning model.TBEM comprises two models:a pure convolutional neural network(CNN)model and a cascaded CNN-Transformer hybrid model.The proposed model won the abovementioned affective BCI competition’s final championship in the 2022 World Robot Contest,demonstrating the effectiveness of the proposed TBEM deep learning model for EEG-based emotion recognition.

Redox-active nanoparticles for inflammatory bowel disease

Homeostasis of gut microbiota is extremely essential for maintaining nutrient metabolism and regulating immunological function.The increasing evidence suggests that inflammatory bowel disease(IBD)is strongly associated with dysregulation of gut microbiota.During activated inflammation,excessive reactive oxygen species(ROS)and reactive nitrogen species(RNS)produced by inflammatory cells play a detrimental role in regulating IBD and gut microbiota.ROS/RNS cause damage to the surrounding tissues,including nutrient absorption disorders,intestinal dysmotility and barrier dysfunction.Meanwhile,ROS/RNS provide terminal electron receptors for anaerobic respiration and support the bloom of facultative anaerobes,eventually causing gut microbiota dysbiosis.Redox-active nanoparticles(NPs)with catalytic properties or enzyme-like activities can effectively scavenge ROS/RNS,and selectively target inflamed sites via ultrasmall size-mediated enhanced permeation and retention(EPR)effect,showing great potential to regulate IBD and maintain the homeostasis of gut microbiota.In addition,the widespread application of NPs in commercial products 1 has increased their accumulation in healthy organisms,and the biological effects on normal microbiota resulting from long-term exposure of NPs to gastrointestinal tract also need attention.

Sendai virus-based immunoadjuvant in hydrogel vaccine intensity-modulated dendritic cells activation for suppressing tumorigenesis

The conventional immunoadjuvants in vaccine have weak effect on stimulating antigen presentation and activating anti-tumor immunity.Unexpectedly,we discovered that non-pathogenic Sendai virus(SeV)could activate antigen-presenting cells(APCs)represented by dendritic cells(DCs).Here,we designed an injectable SeV-based hydrogel vaccine(SHV)to execute multi-channel recruitment and stimulation of DCs for boosting the specific immune response against tumors.After the release of the NIR-triggered antigens from tumor cells,dendritic cells around the vaccine efficiently transport the antigens to lymph nodes and present them to T lymphocytes,thereby inducing systemic anti-tumor immune memory.Our findings demonstrated that the SHV with excellent universality,convenience and flexibility has achieved better immune protection effects in inhibiting the occurrence of melanoma and breast cancer.In conclusion,the SHV system might serve as the next generation of personalized anti-tumor vaccines with enhanced features over standard vaccination regimens,and represented an alternative way to suppress tumorigenesis.