Precise antibacterial therapeutics based on stimuli-responsive nanomaterials.

Bacterial infection refers to the process in which bacteria invade, grow, reproduce, and interact with the body, ultimately causing a series of pathological changes. Nowadays, bacterial infection remains a significant public health issue, posing a huge threat to human health and a serious financial burden. In the post-antibiotic era, traditional antibiotics are prone to inducing bacterial resistance and difficulty in removing bacterial biofilm. In recent years, antibacterial therapy based on nanomaterials has developed rapidly. Compared with traditional antibiotics, nanomaterials effectively remove bacterial biofilms and rarely result in bacterial resistance. However, due to nanomaterials' strong permeability and effectiveness, they will easily cause cytotoxicity when they are not controlled. In addition, the antibacterial effect of non-responsive nanomaterials cannot be perfectly exerted since the drug release property or other antibacterial effects of these nano-materials are not be positively correlated with the intensity of bacterial infection. Stimuli-responsive antibacterial nanomaterials are a more advanced and intelligent class of nano drugs, which are controlled by exogenous stimuli and microenvironmental stimuli to change the dosage and intensity of treatment. The excellent spatiotemporal controllability enables stimuli-responsive nanomaterials to treat bacterial infections precisely. In this review, we first elaborate on the design principles of various stimuli-responsive antibacterial nanomaterials. Then, we analyze and summarizes the antibacterial properties, advantages and shortcomings of different applied anti-bacterial strategies based on stimuli-responsive nanomaterials. Finally, we propose the challenges of employing stimuli-responsive nanomaterials and corresponding potential solutions.

Current Status and Emerging Trends in Colorectal Cancer Screening and Diagnostics.

Colorectal cancer (CRC) is a prevalent and potentially fatal disease categorized based on its high incidences and mortality rates, which raised the need for effective diagnostic strategies for the early detection and management of CRC. While there are several conventional cancer diagnostics available, they have certain limitations that hinder their effectiveness. Significant research efforts are currently being dedicated to elucidating novel methodologies that aim at comprehending the intricate molecular mechanism that underlies CRC. Recently, microfluidic diagnostics have emerged as a pivotal solution, offering non-invasive approaches to real-time monitoring of disease progression and treatment response. Microfluidic devices enable the integration of multiple sample preparation steps into a single platform, which speeds up processing and improves sensitivity. Such advancements in diagnostic technologies hold immense promise for revolutionizing the field of CRC diagnosis and enabling efficient detection and monitoring strategies. This article elucidates several of the latest developments in microfluidic technology for CRC diagnostics. In addition to the advancements in microfluidic technology for CRC diagnostics, the integration of artificial intelligence (AI) holds great promise for further enhancing diagnostic capabilities. Advancements in microfluidic systems and AI-driven approaches can revolutionize colorectal cancer diagnostics, offering accurate, efficient, and personalized strategies to improve patient outcomes and transform cancer management.

Combinatorial optimization and spatial remodeling of CYPs to control product profile.

Activating inert substrates is a challenge in nature and synthetic chemistry, but essential for creating functionally active molecules. In this work, we used a combinatorial optimization approach to assemble cytochrome P450 monooxygenases (CYPs) and reductases (CPRs) to achieve a target product profile. By creating 110 CYP-CPR pairs and iteratively screening different pairing libraries, we demonstrated a framework for establishing a CYP network that catalyzes six oxidation reactions at three different positions of a chemical scaffold. Target product titer was improved by remodeling endoplasmic reticulum (ER) size and spatially controlling the CYPs' configuration on the ER. Out of 47 potential products that could be synthesized, 86% of the products synthesized by the optimized network was our target compound quillaic acid (QA), the aglycone backbone of many pharmaceutically important saponins, and fermentation achieved QA titer 2.23 g/L.

Protocol for photoelectrocatalytic synthesis of aromatic azo compounds from aromatic amines.

Photoelectrocatalytic (PEC) strategy has emerged as a promising approach to drive organic reactions under mild conditions. Here, we present a protocol for PEC oxidative coupling of aromatic amines to produce aromatic azo compounds over a porous BiVO4 nanoarray (BiVO4-NA) photoanode. We describe the fabrication of BiVO4-NA photoanode and the detailed steps for the PEC oxidative coupling reaction, including key performance data of the BiVO4-NA photoanode for synthesizing azobenzene from aniline. For complete details on the use and execution of this protocol, please refer to Luo et al. (2022).1.

Prodigiosin inhibits the proliferation of glioblastoma by regulating the KIAA1524/PP2A signaling pathway.

Prodigiosin (PG), a member of a family of natural red pigments produced by a variety of bacteria, was first discovered in Serratia marcescens. PG has been reported to have an apoptosis-inducing effect in many cancers, such as lymphoma, colon cancer and nasopharyngeal carcinoma. For this study, we used three glioblastoma (GBM) cell lines (LN229, U251 and A172) to explore the effect of prodigiosin on GBM cells. A CCK8 assay was used to evaluate cell viability. We determinedthe cell cycle distribution by flow cytometry and measured proliferation by an EdU incorporation assay. The expression of different molecules was investigated by western blotting and RT-PCR. We further confirmed our results by plasmid transfection and lentiviral transduction. The LN229 xenograft model was used to study the effect of prodigiosin in vivo. We confirmed that prodigiosin played an anticancer role in several GBM cell lines through the KIAA1524/PP2A/Akt signalling pathway. Prodigiosin inhibited the protein expression of KIAA1524 by suppressing its transcription, which led to activation of PP2A. Afterward, PP2A inhibited the phosphorylation of Akt, thereby inducing increased expression of p53/p21. Furthermore, it was verified that prodigiosin inhibited the KIAA1524/PP2A/Akt axis in vivo in the LN229 xenograft model. These data improve the understanding of the anticancer effects of prodigiosin and further highlight the potential of prodigiosin for the development of anti-glioma drugs.

Non-random genetic alterations in the cyanobacterium Nostoc sp. exposed to space conditions.

Understanding the impact of long-term exposure of microorganisms to space is critical in understanding how these exposures impact the evolution and adaptation of microbial life under space conditions. In this work we subjected Nostoc sp. CCCryo 231-06, a cyanobacterium capable of living under many different ecological conditions, and also surviving in extreme ones, to a 23-month stay at the International Space Station (the Biology and Mars Experiment, BIOMEX, on the EXPOSE-R2 platform) and returned it to Earth for single-cell genome analysis. We used microfluidic technology and single cell sequencing to identify the changes that occurred in the whole genome of single Nostoc cells. The variant profile showed that biofilm and photosystem associated loci were the most altered, with an increased variant rate of synonymous base pair substitutions. The cause(s) of these non-random alterations and their implications to the evolutionary potential of single bacterial cells under long-term cosmic exposure warrants further investigation.

Identification and phylogenetic analysis of the genus Syringa based on chloroplast genomic DNA barcoding.

DNA barcoding is a supplementary tool in plant systematics that is extensively used to resolve species-level controversies. This study assesses the significance of using two DNA barcoding loci (e.g., psbA-trnH and trnC-petN) in distinguishing 33 plant samples of the genus Syringa. Results showed that the average genetic distance K2P of psbA-trnH DNA marker was 0.0521, which is much higher than that of trnC-petN, which is 0.0171. A neighbor-joining phylogenetic tree based on psbA-trnH and trnC-petN indicated that the identification rate of psbA-trnH and trnC-petN alone were 75% and 62.5%, respectively. The barcode combination of psbA-trnH+trnC-petN could identify 33 samples of the genus Syringa accurately and effectively with an identification rate of 87.5%. The 33 Syringa samples were divided into four groups: Group I is series Syringa represented by Syringa oblata; Group II is series Villosae represented by Syringa villosa; Group III is series Pubescentes represented by Syringa meyeri; and Group IV is section Ligustrina represented by Syringa reticulata subsp. pekinensis. These research results provided strong evidence that the combinatorial barcode of psbA-trnH+trnC-petN had high-efficiency identification ability and application prospects in species of the genus Syringa.

A Digital Microfluidic Device Integrated with Electrochemical Impedance Spectroscopy for Cell-Based Immunoassay.

The dynamic immune response to various diseases and therapies has been considered a promising indicator of disease status and therapeutic effectiveness. For instance, the human peripheral blood mononuclear cell (PBMC), as a major player in the immune system, is an important index to indicate a patient's immune function. Therefore, establishing a simple yet sensitive tool that can frequently assess the immune system during the course of disease and treatment is of great importance. This study introduced an integrated system that includes an electrochemical impedance spectroscope (EIS)-based biosensor in a digital microfluidic (DMF) device, to quantify the PBMC abundance with minimally trained hands. Moreover, we exploited the unique droplet manipulation feature of the DMF platform and conducted a dynamic cell capture assay, which enhanced the detection signal by 2.4-fold. This integrated system was able to detect as few as 104 PBMCs per mL, presenting suitable sensitivity to quantify PBMCs. This integrated system is easy-to-operate and sensitive, and therefore holds great potential as a powerful tool to profile immune-mediated therapeutic responses in a timely manner, which can be further evolved as a point-of-care diagnostic device to conduct near-patient tests from blood samples.

Whole genome sequencing of cyanobacterium Nostoc sp. CCCryo 231-06 using microfluidic single cell technology.

The Nostoc sp. strain CCCryo 231-06 is a cyanobacterial strain capable of surviving under extreme conditions and thus is of great interest for the astrobiology community. The knowledge of its complete genome sequence would serve as a guide for further studies. However, a major concern has been placed on the effects of contamination on the quality of sequencing data without a reference genome. Here, we report the use of microfluidic technology combined with single cell sequencing and de novo assembly to minimize the contamination and recover the complete genome of the Nostoc strain CCCryo 231-06 with high quality. 100% of the whole genome was recovered with all contaminants removed and a strongly supported phylogenetic tree. The data reported can be useful for comparative genomics for phylogenetic and taxonomic studies. The method used in this work can be applied to studies that require high-quality assemblies of genomes of unknown microorganisms.

Photoelectrocatalytic C-H halogenation over an oxygen vacancy-rich TiO2 photoanode.

Photoelectrochemical cells are emerging as powerful tools for organic synthesis. However, they have rarely been explored for C-H halogenation to produce organic halides of industrial and medicinal importance. Here we report a photoelectrocatalytic strategy for C-H halogenation using an oxygen-vacancy-rich TiO2 photoanode with NaX (X=Cl-, Br-, I-). Under illumination, the photogenerated holes in TiO2 oxidize the halide ions to corresponding radicals or X2, which then react with the substrates to yield organic halides. The PEC C-H halogenation strategy exhibits broad substrate scope, including arenes, heteroarenes, nonpolar cycloalkanes, and aliphatic hydrocarbons. Experimental and theoretical data reveal that the oxygen vacancy on TiO2 facilitates the photo-induced carriers separation efficiency and more importantly, promotes halide ions adsorption with intermediary strength and hence increases the activity. Moreover, we designed a self-powered PEC system and directly utilised seawater as both the electrolyte and chloride ions source, attaining chlorocyclohexane productivity of 412 µmol h-1 coupled with H2 productivity of 9.2 mL h-1, thus achieving a promising way to use solar for upcycling halogen in ocean resource into valuable organic halides.

Amplification of Femtograms of Bacterial DNA Within 3 h Using a Digital Microfluidics Platform for MinION Sequencing.

Whole genome sequencing is emerging as a promising tool for the untargeted detection of a broad range of microbial species for diagnosis and analysis. However, it is logistically challenging to perform the multistep process from sample preparation to DNA amplification to sequencing and analysis within a short turnaround time. To address this challenge, we developed a digital microfluidic device for rapid whole genome amplification of low-abundance bacterial DNA and compared results with conventional in-tube DNA amplification. In this work, we chose Corynebacterium glutamicum DNA as a bacterial target for method development and optimization, as it is not a common contaminant. Sequencing was performed in a hand-held Oxford Nanopore Technologies MinION sequencer. Our results show that using an in-tube amplification approach, at least 1 pg starting DNA is needed to reach the amount required for successful sequencing within 2 h. While using a digital microfluidic device, it is possible to amplify as low as 10 fg of C. glutamicum DNA (equivalent to the amount of DNA within a single bacterial cell) within 2 h and to identify the target bacterium within 30 min of MinION sequencing-100× lower than the detection limit of an in-tube amplification approach. We demonstrate the detection of C. glutamicum DNA in a mock community DNA sample and characterize the limit of bacterial detection in the presence of human cells. This approach can be used to identify microbes with minute amounts of genetic material in samples depleted of human cells within 3 h.

Changes of arachnoid granulations after subarachnoid hemorrhage in cynomolgus monkeys.

This research explores ultrastructural changes of arachnoid granulations associated with hydrocephalus after subarachnoid hemorrhage in cynomolgus monkeys. It provides a theoretical basis for further study of the etiology and prevention of hydrocephalus. Female cynomolgus monkeys about one-year-old were selected. The position range of arachnoid granulations in superior sagittal sinus and transverse sinus was determined in a randomly selected control monkey. The morphology of normal arachnoid granulations in cynomolgus monkeys was observed under a transmission electron microscope. A primate model of subarachnoid hemorrhage was established by injecting autologous blood into cisterna magna. Vomiting, movement disorder, and reduced level of consciousness were gradually observed in monkeys. Computed tomography and magnetic resonance imaging scan results confirmed subarachnoid hemorrhage and hydrocephalus, and the morphology of arachnoid granulations in hydrocephalus was observed under a transmission electron microscope. Extensive fibrosis of arachnoid granulations was observed under a transmission electron microscope in cynomolgus monkeys with hydrocephalus after subarachnoid hemorrhage.

Quantitative evaluation of rejuvenation treatment of nasolabial fold wrinkles by regression model and 3D photography.

OBJECTIVE: With the application of 3D photography, our study aimed to quantify parameters of static nasolabial fold wrinkles and establish mathematic regression model between parameters of wrinkles and age, further to quantitatively evaluate the effect of rejuvenation treatment in terms of age. METHODS: From October 2016 to May 2018, 433 Chinese female volunteers, aged 25-60 years old, were enrolled in this study. Antera 3D camera was used to collect four parameters of static nasolabial fold wrinkles on the left and right sides of the volunteers, including overall size, average depth (mm), average width (mm), and maximum depth (mm). For those presented a linear relationship with age, univariate linear regression fitting was performed, followed by residual analysis, goodness of fit test, and significance test. RESULTS: The results of univariate linear regression fitting showed there was a clear linear relationship between the maximum depth, average depth, overall size of nasolabial fold wrinkles and age, and the regression equations were established. The significance test of regression coefficients showed P values were less than .0001. CONCLUSIONS: With application of the regression model between parameters of nasolabial fold wrinkles and age, the effect of rejuvenation treatment can be quantitatively evaluated in terms of age, which has certain reference and promotion value.

Synergistic lignin construction of a long-chain branched polypropylene and its properties.

In light of current environmental pressures (referring to its destruction) and the consumption of petrochemical resources, the substitution of chemicals products with renewable natural substances has attracted extensive interest. In this paper, a synergistically constructed lignin polypropylene matrix composite with long-chain branched characteristics was prepared by a pre-irradiation and melt blending method. The effects of lignin on the crystallization, rheological behavior, foaming and aging properties of polypropylene were studied. Differential scanning calorimetry and polarized light microscopy results show that lignin undergoes heterophasic nucleation in a polypropylene matrix; rheological studies show that lignin promotes the formation of a heterogeneous polypropylene network, and thus polypropylene exhibits long-chain branching features; nucleation and a network structure endow the polypropylene-based composites with uniform cell size, thin cell walls, and a foaming ratio of 5-44 times; at the same time, a large number of hindered phenols in lignin can capture free radicals to improve the aging properties of the polypropylene. This research will help to convert industrial waste into functional composite materials.

The effects of rubber nanoparticles with different polarities on thermal properties and foaming performance of polypropylene blends.

Polypropylene blends with both polybutadiene rubber (PB) and polycarboxylbuturonile rubber (xNBR) and the required amount of acrylamide (AM) was prepared by blending with water, and the crystallinity, rheological behaviour and thermal performance were analysed and compared. The results of DSC and XRD characterization showed an obvious enhancement in the crystallization of the PP matrix in PP/xNBR/AM blends compared to PP/PB/AM blends, due to the strong incompatibility between xNBR nanoparticles and the PP polymer matrix leading to the inhibition of segmental mobility and induced formation of heterogeneous nuclei. Rheological analysis showed that the dynamical mobility of polymer chains was retarded while the AM monomer was incorporated, due to strengthening interfacial interactions by grafts through hydrogen bonding. The foaming performance was clearly improved, as reflected in the uniform cell morphology and higher cell density, and the expansion ratio achieved was 13-fold. In addition, the decomposition temperature increased from 403 °C to 465 °C by nearly 62 °C as compared with neat PP, which is ascribed to the inhibition of segmental mobility due to the cyclization reaction of nitriles. The increase in the surface energy was about 2.2-fold, which resulted in a decrease of the water contact angle from 105.3° to 83.7°, attributed due to AM addition to the composition.

Quantitative Proteomic Analysis Reveals Impaired Axonal Guidance Signaling in Human Postmortem Brain Tissues of Chronic Traumatic Encephalopathy.

Chronic traumatic encephalopathy (CTE) is a distinct neurodegenerative disease that associated with repetitive head trauma. CTE is neuropathologically defined by the perivascular accumulation of abnormally phosphorylated tau protein in the depths of the sulci in the cerebral cortices. In advanced CTE, hyperphosphorylated tau protein deposits are found in widespread regions of brain, however the mechanisms of the progressive neurodegeneration in CTE are not fully understood. In order to identify which proteomic signatures are associated with CTE, we prepared RIPA-soluble fractions and performed quantitative proteomic analysis of postmortem brain tissue from individuals neuropathologically diagnosed with CTE. We found that axonal guidance signaling pathwayrelated proteins were most significantly decreased in CTE. Immunohistochemistry and Western blot analysis showed that axonal signaling pathway-related proteins were down regulated in neurons and oligodendrocytes and neuron-specific cytoskeletal proteins such as TUBB3 and CFL1 were reduced in the neuropils and cell body in CTE. Moreover, oligodendrocyte-specific proteins such as MAG and TUBB4 were decreased in the neuropils in both gray matter and white matter in CTE, which correlated with the degree of axonal injury and degeneration. Our findings indicate that deregulation of axonal guidance proteins in neurons and oligodendrocytes is associated with the neuropathology in CTE. Together, altered axonal guidance proteins may be potential pathological markers for CTE.

Whole genome amplification of single epithelial cells dissociated from snap-frozen tissue samples in microfluidic platform.

Single cell sequencing is a technology capable of analyzing the genome of a single cell within a population. This technology is mostly integrated with microfluidics for precise cell manipulation and fluid handling. So far, most of the microfluidic-based single cell genomic studies have been focused on lab-cultured species or cell lines that are relatively easy to handle following standard microfluidic-based protocols without additional adjustments. The major challenges for performing single cell sequencing on clinical samples is the complex nature of the samples which requires additional sample processing steps to obtain intact single cells of interest without using amplification-inhibitive agents. Fluorescent-activated cell sorting is a common option to obtain single cells from clinical samples for single cell applications but requires >100 000 viable cells in suspension and the need for specialized laboratory and personnel. In this work, we present a protocol that can be used to obtain intact epithelial cells from snap-frozen postsurgical human endometrial tissues for single cell whole genome amplification. Our protocol includes sample thawing, cell dissociation, and labeling for genome amplification of targeted cells. Between 80% and 100% of single cell replicates lead to >25 ng of DNA after amplification with no measurable contamination, sufficient for downstream sequencing.

Bacterial Single Cell Whole Transcriptome Amplification in Microfluidic Platform Shows Putative Gene Expression Heterogeneity.

Single cell RNA sequencing is a technology that provides the capability of analyzing the transcriptome of a single cell from a population. So far, single cell RNA sequencing has been focused mostly on human cells due to the larger starting amount of RNA template for subsequent amplification. One of the major challenges of applying single cell RNA sequencing to microbial cells is to amplify the femtograms of the RNA template to obtain sufficient material for downstream sequencing with minimal contamination. To achieve this goal, efforts have been focused on multiround RNA amplification, but would introduce additional contamination and bias. In this work, we for the first time coupled a microfluidic platform with multiple displacement amplification technology to perform single cell whole transcriptome amplification and sequencing of Porphyromonas somerae, a microbe of interest in endometrial cancer, as a proof-of-concept demonstration of using single cell RNA sequencing tool to unveil gene expression heterogeneity in single microbial cells. Our results show that the bacterial single-cell gene expression regulation is distinct across different cells, supporting widespread heterogeneity.

Acetylated SEBS Enhanced DC Insulation Performances of Polyethylene.

Acetophenone can significantly improve the dielectric properties of polyethylene (PE) insulation materials. However, it easily migrates from the PE due to its poor compatibility with the material, which limits its application. In this paper, the functional units of acetophenone were modified in polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) by an acetylation reaction, and SEBS was used as the carrier to inhibit the migration of acetophenone. The number of functional units in the acetylated SEBS (Ac-SEBS) was measured by 1H NMR and the effect of the acetylation degree of SEBS on its compatibility with PE was studied. Meanwhile, the effects of Ac-SEBS on PE's direct current (DC) breakdown strength and space charge accumulation characteristics were investigated. It is demonstrated that Ac-SEBS can significantly improve the field strength of the DC breakdown and inhibit the accumulation of space charge in the PE matrix. This work provides a new approach for the application of aromatic compounds as voltage stabilizers in DC insulation cable materials.