Programming the Assembly of Oligo-Adenine with Coralyne into a pH-Responsive DNA Hydrogel.

External stimuli-responsive DNA hydrogels present interesting platforms for drug loading and triggered release. Typically, drug molecules are encapsulated within three-dimensionally hybridized DNA networks. However, the utilization of drug molecules as cofactors to facilitate the directed assembly of DNA strands into hydrogel frameworks and their subsequent controlled release remains to be explored. Herein, we introduce the guided assembly of oligo-adenine (A-strand) into an acidic pH-responsive DNA hydrogel using an anticancer drug, coralyne (COR), as a low-molecular-weight cofactor. At pH 7, COR orchestrates the assembly of A-strand into an antiparallel duplex configuration cross-linked by A-COR-A units at a stoichiometric ratio of one COR cofactor per four adenine bases, resulting in a DNA hydrogel characterized by A-COR-A duplex bridges. At pH 4-5, the instability of A-COR-A units results in the disintegration of the duplex into its constituent components, leading to the release of COR and simultaneous dissociation of the DNA hydrogel matrix. This study introduces a method by which drug molecules, exemplified here by COR, facilitate the direct formation of a supramolecular cofactor-DNA complex, subsequently leading to the creation of a stimuli-responsive DNA hydrogel. This approach may inspire future investigations into DNA hydrogels tailored for controlled drug encapsulation and release applications.

2,3,5,4'- tetrahydroxystilbene-2-O-ß-D- glucopyranoside (TSG)-Driven immune response in the hepatotoxicity of Polygonum multiflorum.

ETHNOPHARMACOLOGICAL RELEVANCE: 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucopyranoside (TSG) as the primary constituent of Polygonum multiflorum Thumb. (PM) possesses anti-oxidative, antihypercholesterolemic, anti-tumor and many more biological activities. The root of PM has been used as a tonic medicine for thousands of years. However, cases of PM-induced liver injury are occasionally reported, and considered to be related to the host immune status. AIM OF THE STUDY: The primary toxic elements and specific mechanisms PM causing liver damage are still not thoroughly clear. Our study aimed to investigate the influences of TSG on the immune response in idiosyncratic hepatotoxicity of PM. MATERIALS AND METHODS: The male C57BL/6 mice were treated with different doses of TSG and the alterations in liver histology, serum liver enzyme levels, proportions of T cells and cytokines secretion were evaluated by hematoxylin and eosin (HE), RNA sequencing, quantitative real time polymerase chain reaction (qRT-PCR), Flow cytometry (FCM), and enzyme-linked immunosorbent assay (ELISA), respectively. Then, primary spleen cells from drug-naive mice were isolated and cultured with TSG in vitro. T cell subsets proliferation and cytokines secretion after treated with TSG were assessed by CCK8, FCM and ELISA. In addition, mice were pre-treated with anti-CD25 for depleting regulatory T cells (Tregs), and then administered with TSG. Liver functions and immunological alterations were analyzed to evaluate liver injury. RESULTS: Data showed that TSG induced liver damage, and immune cells infiltration in the liver tissues. FCM results showed that TSG could activate CD4+T and CD8+T in the liver. Results further confirmed that TSG notably up-regulated the levels of inflammatory cytokines including TNF-α, IFN-γ, IL-18, perforin and granzyme B in the liver tissues. Furthermore, based on transcriptomics profiles, some immune system-related pathways including leukocyte activation involved in inflammatory response, leukocyte cell-cell adhesion, regulation of interleukin-1 beta production, mononuclear cell migration, antigen processing and presentation were altered in TSG treated mice. CD8+T/CD4+T cells were also stimulated by TSG in vitro. Interestingly, increased proportion of Tregs was observed after TSG treatment in vitro and in vivo. Foxp3 and TGF-ß1 mRNA expressions were up-regulated in the liver tissues. Depletion of Tregs moderately enhanced TSG induced the secretion of inflammatory cytokines in serum. CONCLUSIONS: Our findings showed that TSG could trigger CD4+T and CD8+T cells proliferation, promote cytokines secretion, which revealed that adaptive immune response associated with the mild liver injury cause by TSG administration. Regulatory T cells (Tregs) mainly sustain immunological tolerance, and in this study, the progression of TSG induced liver injury was limited by Tregs. The results of our investigations allow us to preliminarily understand the mechanisms of PM related idiosyncratic hepatotoxicity.

A Self-Immolative DNA Nanogel Vaccine toward Cancer Immunotherapy.

The development of precisely engineered vehicles for intracellular delivery and the controlled release of payloads remains a challenge. DNA-based nanomaterials offer a promising solution based on the A-T-G-C alphabet-dictated predictable assembly and high programmability. Herein, we present a self-immolative DNA nanogel vaccine, which can be tracelessly released in the intracellular compartments and activate the immune response. Three building blocks with cytosine-rich overhang domains are designed to self-assemble into a DNA nanogel framework with a controlled size. Two oligo agonists and one antigen peptide are conjugated to the building blocks via an acid-labile chemical linker. Upon internalization into acidic endosomes, the formation of i-motif configurations leads to dissociation of the DNA nanogel vaccine. The acid-labile chemical linker is cleaved, releasing the agonists and antigen in their traceless original form to activate antigen-presenting cells and an immune response. This study presents a novel strategy for constructing delivery platforms for intracellularly stimuli-triggered traceless release of therapeutics.

Unraveling the complexities of beryllium contamination in agricultural soils: The case of Qingcheng District, Qingyuan City.

Metal contamination in agricultural soils has received widespread attention; however, the status of beryllium (Be) contamination in agricultural soils has been inadequately studied. This research was conducted to determine the enrichment level and major sources of Be contamination in the agricultural soil in Qingcheng District, Qingyuan City, and to quantify the potential ecological risk and human health risk (PER and HHR) of Be by integrating geological mineral and remote-sensing image maps. The results of principal component analysis followed by multiple linear regression (PCA-MLR) suggest that Be, Sn, Zn, Pb, As, and Cd are mainly derived from anthropogenic activities; V, Ti, Sc, Cr, and Co are mainly derived from medium acidic granites; Al and Si are mainly derived from geological sources; and K and Na are mainly derived from calcium-alkaline materials. Anthropogenic activities are priority material sources owing to the highest contribution. Be contamination poses a slight PER, and the PER level of agricultural soil was moderate. The HHR caused by Be is negligible. The results of this study can serve as the basis for promoting agricultural soil protection and developing and implementing agricultural policies to reduce environmental pollution in the study area.

Silencing of V-ATPase-E gene causes midgut apoptosis of Diaphorina citri and affects its acquisition of Huanglongbing pathogen.

The Asian citrus psyllid, Diaphorina citri Kuwayama, is among the most important pests of citrus. It is the main vector of the Huanglongbing (HLB) pathogen Candidatus Liberibacter asiaticus (CLas), which causes severe losses in citrus crops. Control of D. citri is therefore of paramount importance to reduce the spread of HLB. In this regard, using RNA interference (RNAi) to silence target genes is a useful strategy to control psyllids. In this study, using RNAi, we examined the biological functions of the V-ATPase subunit E (V-ATP-E) gene of D. citri, including its effect on acquisition of CLas. The amino acid sequence of V-ATP-E from D. citri had high homology with proteins from other insects. V-ATP-E was expressed at all D. citri life stages analyzed, and the expression level in mature adults was higher than that of teneral adults. Silencing of V-ATP-E resulted in a significant increase in mortality, reduced body weight, and induced cell apoptosis of the D. citri midgut. The reduced expression of V-ATP-E was indicated to inhibit CLas passing through the midgut and into the hemolymph, leading to a majority of CLas being confined to the midgut. In addition, double-stranded RNA of D. citri V-ATP-E was safe to non-target parasitic wasps. These results suggest that V-ATP-E is an effective RNAi target that can be used in D. citri control to block CLas infection.

An elastic MOF/graphene aerogel with high photothermal efficiency for rapid removal of crude oil.

Due to the frequent spill accidents during crude oil exploration and transport, to rapidly cleanup crude oil and eliminate the environmental pollution of oil spill is in high demand. In this work, a three-dimensional graphene aerogel (MEGA) with high elasticity, photothermal conversion capacity and adsorption capacity was prepared for rapid removal of crude oil. The results showed that the as-prepared MEGA exhibited a layered structure, the octahedral HKUST-1 nanoparticles and hydrophobic polydimethylsiloxane (PDMS) coatings were uniformly deposited on the surface. Such a hierarchical micro-nano porous structure not only improved the aerogel's hydrophobicity (water contact angle in air up to 152.7°), but also endowed it with strong oil adsorption capacity (41-118 times of its own weight). Especially, the MEGA showed excellent photothermal conversion capacity. Under light irradiation, its temperature raised to 80 â„ƒ from room temperature in 100 s. As a result, the adsorption for one drop of crude oil by MEGA was shortened from 5 h to 40 s, comparing with that in dark condition. In addition, the MEGA showed remarkable elasticity and mechanical stability, it could maintain more than 90% efficiency after 10 adsorption-compression cycles. This study suggests that the prepared MEGA has great potential for rapid removal of crude oil.

Morphological and physiological mechanism of cytoplasmic inheritance stigma exsertion trait expression in tobacco (Nicotiana tabacum).

Stigma exsertion is an essential outcrossing trait that can improve hybrid seed production efficiencies. In this study, the morphological and physiological mechanisms of cytoplasmic inheritance stigma exsertion trait expression in a tobacco line (MSK326SE) which generated from a stigma exsertion tobacco mutant through continuous backcross were investigated. Compared with its homonuclear-heteroplasmic lines (MSK326 and K326 with inserted stigmas), the exserted stigma phenotype of MSK326SE was mainly caused by corolla shortening, while was stable under different environmental temperature. The different responses of mainly endogenous hormones and expression of cell division- and expansion-related genes caused the differences in cell division and expansion in different flower organs, which further determined the lengths of the corolla. Furthermore, the significant decrease of MSK326SE corolla epidermal cell size caused corolla shortening and finally resulting in stigma exsertion. Exogenous JA could shorten the corolla and more effective increased stigma exsertion degree of MSK326SE, suggesting a potential relationship between stigma exsertion and high JA levels during early bud development. The hybrid seed production efficiency could be improved in tobacco. Our results provide a basis for elucidating the cytoplasmic inheritance stigma exsertion trait expression in tobacco while helping to improve hybrid seed production efficiency.

Spatial distribution characteristics, influencing factors, and source distribution of soil cadmium in Shantou City, Guangdong Province.

A total of 511 topsoils and 139 deep soil samples were collected to analyze the distribution characteristics, regional differentiation factors, and contamination sources of Cd in Shantou City, and to assess its environmental, ecological, and human health risks. We used a combination of multivariate statistics and geostatistics to quantify the distribution and level of Cd contamination in the study area, and an absolute principal component scores-multiple linear regression model to resolve the sources of contamination and their contribution values, combined with the health risk model to assess the human health risk from each source. The result exhibited that the average value of soil Cd content was 0.100 mg/kg, which was lower than the threshold value of soil environmental quality standard, but higher than the 0.070 mg/kg background value of soil. The high-value areas of surface Cd content in the study area were distributed in the western, northern, and northeastern parts of Shantou, and the source of Cd in the soil was a mix of anthropogenic and natural contamination. The non-carcinogenic and carcinogenic risks of heavy metal Cd exposure pathways are: oral ingestion > dermal contact > inhalation. The human health risk posed by Cd is below the reference threshold, indicating that the Cd contents in the soil have no unacceptable health risk to the residents. Among industrial sources, natural sources, and unknown sources with potential carcinogenic and non-carcinogenic risks, natural sources were the main source of contamination for adults and children. Among the different soil types, paddy, and red soils had relatively high Cd content, and among the different soil-forming parent materials, the Cd content in soils developed on Quaternary sediments was significantly higher than that other parent materials. Among the different land use types, the Cd content of soil for construction land was the highest. This study provides a scientific foundation and reference for the prevention of soil Cd contamination in Shantou City and the analysis of soil contamination sources in areas with similar contamination patterns.

Causes of Lower Respiratory Tract Infections and the Use of Diagnostic Biomarkers in Blood Samples from Children in Hohhot, Inner Mongolia, China, Between July 2019 and June 2020.

BACKGROUND Lower respiratory tract infection (LRTI) in children is due to various pathogens. Appropriate diagnosis and early treatment are important for reducing the mortality rate of LRTI. Data on the epidemiology profiles of LRTI are scarce in northern China. The aim of this study was to provide data on the pathogen pattern of LRTI in hospitalized children in Hohhot, Inner Mongolia, China. MATERIAL AND METHODS From July 2019 to June 2020, nasopharyngeal swabs were collected from 265 children in Hohhot with LRTI, and pathogens were detected with RT-PCR and PCR. The correlations among procalcitonin (PCT), C-reactive protein (CRP), and white blood cells (WBC) with acute respiratory infections were evaluated. RESULTS The highest prevalence of LRTI was detected in 2- to 6-year-old children (149, 56.2%) in winter. Eleven respiratory pathogens were evaluated, and respiratory syncytial virus, Streptococcus pneumoniae and Haemophilus influenza were the most common pathogens in this region. Single viruses, bacteria, mycoplasma, and multiple pathogens were identified in 24.2, 15.8, 5.3, and 54.7% of patients, respectively. The mean blood biomarker values of patients with LRTI were significantly different from those of healthy children. Furthermore, The AUCs were 0.90, 0.74, and 0.84 for bacteria, virus, and mycoplasma PCT values, which were significantly higher than that of WBC and CRP. CONCLUSIONS This evaluation of the regional pattern of pathogens in children with acute respiratory infections and the correlation with blood biomarkers provides valuable information for the prevention and treatment of LRTI in children.

A Remotely Controlled Transformable Soft Robot Based on Engineered Cardiac Tissue Construct.

Many living organisms undergo conspicuous or abrupt changes in body structure, which is often accompanied by a behavioral change. Inspired by the natural metamorphosis, robotic systems can be designed as reconfigurable to be multifunctional. Here, a tissue-engineered transformable robot is developed, which can be remotely controlled to assume different mechanical structures for switching locomotive function. The soft robot is actuated by a muscular tail fin that emulates the swimming of whales and works as a cellular engine powered by the synchronized contraction of striated cardiac microtissue constructs. For a transition of locomotive behavior, the robot can be optically triggered to transform from a spread to a retracted form, which effectively changes the bending stiffness of the tail fins, thus minimizing the propulsion output from the "tail fin" and effectively switching off the engine. With the unprecedented controllability and responsiveness, the transformable robot is implemented to work as a cargo carrier for programmed delivery of chemotherapeutic agents to selectively eradicate cancer cells. It is believed that the realization of the transformable concept paves a pathway for potential development of intelligent biohybrid robotic systems.

Ultrahigh-throughput droplet microfluidic device for single-cell miRNA detection with isothermal amplification.

Analysis of microRNA (miRNA), a pivotal primary regulator of fundamental cellular processes, at the single-cell level is essential to elucidate regulated gene expression precisely. Most single-cell gene sequencing methods use the polymerase chain reaction (PCR) to increase the concentration of the target gene for detection, thus requiring a barcoding process for cell identification and creating a challenge for real-time, large-scale screening of sequences in cells to rapidly profile physiological samples. In this study, a rapid, PCR-free, single-cell miRNA assay is developed from a continuous-flow microfluidic process employing a DNA hybridization chain reaction to amplify the target miRNA signal. Individual cells are encapsulated with DNA amplifiers in water-in-oil droplets and then lysed. The released target miRNA interacts with the DNA amplifiers to trigger hybridization reactions, producing fluorescence signals. Afterward, the target sequences are recycled to trigger a cyclic cascade reaction and significantly amplify the fluorescence signals without using PCR thermal cycling. Multiple DNA amplifiers with distinct fluorescence signals can be encapsulated simultaneously in a droplet to measure multiple miRNAs from a single cell simultaneously. Moreover, this process converts the lab bench PCR assay to a real-time droplet assay with the post-reaction fluorescence signal as a readout to allow flow cytometry-like continuous-flow measurement of sequences in a single cell with an ultrahigh throughput (300-500 cells per minute) for rapid biomedical identification.

Synthesis of Size-Tunable Hollow Polypyrrole Nanostructures and Their Assembly into Folate-Targeting and pH-Responsive Anticancer Drug-Delivery Agents.

Chemotherapeutic drugs currently used in clinical settings have high toxicity, low specificity, and short half-lives. Herein, polypyrrole-based anticancer drug nanocapsules were prepared by tailoring the size of the nanoparticles with a template method, controlling drug release by means of an aromatic imine, increasing nanoparticle stability through PEGylation, and improving tumor-cell selectivity by folate mediation. The nanoparticles were characterized by TEM and dynamic light scattering. α-Folate receptor expression levelsof tumor cells and normal cells were investigated by western blot and quantitative polymerase chain reaction analyses. Flow cytometry and fluorescence imaging were used to verify the cell uptake of the different-sized nanoparticles. From the different-sized polypyrrole nanoparticles, the optimally functionalized nanoparticles of 180 nm hydrodynamic diameter were chosen and further usedfor in vitroandin vivotests. The nanoparticles showed excellent biocompatibility and the drug-loaded nanoparticles exhibited effective inhibition of tumor cell growth in vitro. Moreover, the drug-loaded nanoparticles showed substantially enhanced accumulation in tumor regions and effectively inhibitedin vivotumor growth. Furthermore, the nanoparticles showed reduced doxorubicin-induced toxicity andno significant side effects in normal organs of tumor-bearing mice, as measured by body-weight shifts and evaluationof drug distribution. Overall, the functionalized nanoparticles are promising nanocarriers for tumor-targeting drug delivery.

Multifunctional halloysite nanotubes for targeted delivery and controlled release of doxorubicin in-vitro and in-vivo studies.

The current state of cancer therapy encourages researchers to develop novel efficient nanocarriers. Halloysite nanotubes (HNTs) are good nanocarrier candidates due to their unique nanoscale (40-80 nm in diamter and 200-500 nm in length) and hollow lumen, as well as good biocompatibility and low cost. In our study, we prepared a type of folate-mediated targeting and redox-triggered anticancer drug delivery system, so that Doxorubicin (DOX) can be specifically transported to tumor sites due to the over-expressed folate-receptors on the surface of cancer cells. Furthermore, it can then be released by the reductive agent glutathione (GSH) in cancer cells where the content of GSH is nearly 103-fold higher than in the extracellular matrix. A series of methods have demonstrated that per-thiol-ß-cyclodextrin (ß-CD-(SH)7) was successfully combined with HNTs via a redox-responsive disulfide bond, and folic acid-polyethylene glycol-adamantane (FA-PEG-Ad) was immobilized on the HNTs through the strong complexation between ß-CD/Ad. In vitro studies indicated that the release rate of DOX raised sharply in dithiothreitol (DTT) reducing environment and the amount of released DOX reached 70% in 10 mM DTT within the first 10 h, while only 40% of DOX was released in phosphate buffer solution (PBS) even after 79 h. Furthermore, the targeted HNTs could be specifically endocytosed by over-expressed folate-receptor cancer cells and significantly accelerate the apoptosis of cancer cells compared to non-targeted HNTs. In vivo studies further verified that the targeted HNTs had the best therapeutic efficacy and no obvious side effects for tumor-bearing nude mice, while free DOX showed damaging effects on normal tissues. In summary, this novel nanocarrier system shows excellent potential for targeted delivery and controlled release of anticancer drugs and provides a potential platform for tumor therapy.

Orthogonal Dual-Triggered Shape-Memory DNA-Based Hydrogels.

DNA-based shape-memory hydrogels revealing switchable shape recovery in the presence of two orthogonal triggers are described. In one system, a shaped DNA/acrylamide hydrogel is stabilized by duplex nucleic acids and pH-responsive cytosine-rich, i-motif, bridges. Separation of the i-motif bridges at pH 7.4 transforms the hydrogel into a quasi-liquid, shapeless state, that includes the duplex bridges as permanent shape-memory elements. Subjecting the quasi-liquid state to pH 5.0 or Ag(+) ions recovers the hydrogel shape, due to the stabilization of the hydrogel by i-motif or C-Ag(+) -C bridged i-motif. The cysteamine-induced transformation of the duplex/C-Ag(+) -C bridged i-motif hydrogel into a quasi-liquid shapeless state results in the recovery of the shaped hydrogel in the presence of H(+) or Ag(+) ions as triggers. In a second system, a shaped DNA/acrylamide hydrogel is generated by DNA duplexes and bridging Pb(2+) or Sr(2+) ions-stabilized G-quadruplex subunits. Subjecting the shaped hydrogel to the DOTA or KP ligands eliminates the Pb(2+) or Sr(2+) ions from the respective hydrogels, leading to shapeless, memory-containing, quasi-liquid states that restore the original shapes with Pb(2+) or Sr(2+) ions.

pH-responsive and switchable triplex-based DNA hydrogels.

New methods for the preparation of reversible pH-responsive DNA hydrogels based on Hoogsteen triplex structures are described. One system consists of a hydrogel composed of duplex DNA units that bridge acrylamide chains at pH = 7.4 and undergoes dissolution at pH = 5.0 through the reconfiguration of one of the duplex bridging units into a protonated CG·C+ triplex structure. The second system consists of a hydrogel consisting of acrylamide chains crosslinked in the presence of an auxiliary strand by Hoogsteen TA·T triplex interaction at pH = 7.0. The hydrogel transforms into a liquid phase at pH = 10.0 due to the separation of the triplex bridging units. The two hydrogel systems undergo reversible and cyclic hydrogel/solution transitions by subjecting the systems to appropriate pH values. The anti-cancer drug, coralyne, binds specifically to the TA·T triplex-crosslinked hydrogel thereby increasing its stiffness. The pH-controlled release of the coralyne from the hydrogel is demonstrated.

Perylene ligand wrapping G-quadruplex DNA for label-free fluorescence potassium recognition.

A perylene ligand, N,N-bis-(1-aminopropyl-3-propylimidazol salt)-3,4,9,10-perylene tetracarboxylic acid diimide ligand (PDI), which consisted of π-conjugated perylene moiety and hydrophilic side chains with positively charged imidazole rings, was used to wrap G-quadruplex for fluorescence turn-on K(+) recognition. Electrostatic attraction between PDI's positively charged imidazole rings and DNA's negatively charged phosphate backbones enabled PDI to accumulate on DNA. Upon trapping K(+), these G-rich DNA sequences transitioned to G-quadruplex. Subsequently, PDI ligands wrapped G-quadruplex, in which the flat aromatic core of PDI ligand interacted with G-quartet through π-π stacking and the side chains were positioned in grooves through electrostatic interactions. Consequently, the interaction mode change and conformational transition from PDI stacked G-sequence to PDI wrapped G-quadruplex led to PDI fluorescence enhancement, which was readily monitored as the detection signal. This strategy excluded the sequence tagging step and exhibited high selectivity and sensitivity towards K(+) ion with the linear detection range of 10-150 nM. Besides, PDI ligands may hold diagnostic and therapeutic application potentials to human telomere and cancer cells.

Development time and body size in Eupolyphaga sinensis along a latitudinal gradient from China.

The responses of organisms to temperature variations may be via short term responses of the phenotype (phenotypic plasticity), or they could involve long-term evolutionary change and adaptation (via selection) to the genotype. These could involve changes to the mean size of the animal or to the thermal reaction norm. We examined the effects of various temperatures (of 22, 25, 28, and 31 °C) on development time, adult body size and preadult survivorship in three populations of the cockroach, Eupolyphaga sinensis (Walker), collected at different latitudes. We found substantial temperature-induced plasticity in development time, body size, and preadult survivorship, indicating that developmental temperatures have strong impacts on growth and life history traits of E. sinensis. Genetic differences for development time, body size, and preadult survivorship were detected among populations, and the three traits exhibited highly significant variations in the responses of different populations to various temperature conditions, indicating genetic differences among populations in terms of thermal reaction norms. We also found that two populations seem to support the beneficial acclimation hypothesis whereas the third mid-latitude population does not. The results are likely because of differences in season length and voltinism, indicating that not only temperature regime but also its interactions with generation time (and development time), voltinism, and season length are likely to have considerable effects on insect development time and body size. Overall, changes in development time, body size, and preadult survivorship in E. sinensis can all be regarded as adaptations to changing thermal regimes.