Humidity Adaptive Antifreeze Hydrogel Sensor for Intelligent Control and Human-Computer Interaction.

Conductive hydrogels have emerged as ideal candidate materials for strain sensors due to their signal transduction capability and tissue-like flexibility, resembling human tissues. However, due to the presence of water molecules, hydrogels can experience dehydration and low-temperature freezing, which greatly limits the application scope as sensors. In this study, an ionic co-hybrid hydrogel called PBLL is proposed, which utilizes the amphoteric ion betaine hydrochloride (BH) in conjunction with hydrated lithium chloride (LiCl) thereby achieving the function of humidity adaptive. PBLL hydrogel retains water at low humidity (<50%) and absorbs water from air at high humidity (>50%) over the 17 days of testing. Remarkably, the PBLL hydrogel also exhibits strong anti-freezing properties (-80 °C), high conductivity (8.18 S m-1 at room temperature, 1.9 S m-1 at -80 °C), high gauge factor (GF approaching 5.1). Additionally, PBLL hydrogels exhibit strong inhibitory effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), as well as biocompatibility. By synergistically integrating PBLL hydrogel with wireless transmission and Internet of Things (IoT) technologies, this study has accomplished real-time human-computer interaction systems for sports training and rehabilitation evaluation. PBLL hydrogel exhibits significant potential in the fields of medical rehabilitation, artificial intelligence (AI), and the Internet of Things (IoT).

Breast tumor-on-chip: from the tumor microenvironment to medical applications.

With the development of microfluidic technology, tumor-on-chip models have gradually become a new tool for the study of breast cancer because they can simulate more key factors of the tumor microenvironment compared with traditional models in vitro. Here, we review up-to-date advancements in breast tumor-on-chip models. We summarize and analyze the breast tumor microenvironment (TME), preclinical breast cancer models for TME simulation, fabrication methods of tumor-on-chip models, tumor-on-chip models for TME reconstruction, and applications of breast tumor-on-chip models and provide a perspective on breast tumor-on-chip models. This review will contribute to the construction and design of microenvironments for breast tumor-on-chip models, even the development of the pharmaceutical field, personalized/precision therapy, and clinical medicine.

Biotechnological potential of a rhizosphere Pseudomonas aeruginosa strain producing phenazine-1-carboxylic acid and phenazine-1-carboxamide.

Bacterial phenazine metabolites belong to a group of nitrogen-containing heterocyclic compounds with antimicrobial activities. In this study, a rhizosphere Pseudomonas aeruginosa strain PA1201 was isolated and identified through 16S rDNA sequence analysis and fatty acid profiling. PA1201 inhibited the growth of various pathogenic microorganisms, including Rhizotonia solani, Magnaporthe grisea, Fusarium graminearum, Xanthomonas oryzae pv. oryzae, Xanthomonas oryzae pv. oryzicola, and Staphylococcus aureus. High Performance Liquid Chromatography showed that PA1201 produced high levels of phenazine-1-carboxylic acid (PCA), a registered green fungicide 'Shenqinmycin' with the fermentation titers of 81.7 mg/L in pigment producing medium (PPM) and 926.9 mg/L in SCG medium containing soybean meal, corn steep liquor and glucose. In addition, PA1201 produced another antifungal metabolite, phenazine-1-carboxaminde (PCN), a derivative of PCA, with the fermentation titers of 18.1 and 489.5 mg/L in PPM and SCG medium respectively. To the best of our knowledge, PA1201 is a rhizosphere originating P. aeruginosa strain that congenitally produces the highest levels of PCA and PCN among currently reported P. aeruginosa isolates, which endows it great biotechnological potential to be transformed to a biopesticide-producing engineering strain.

Engineering the central biosynthetic and secondary metabolic pathways of Pseudomonas aeruginosa strain PA1201 to improve phenazine-1-carboxylic acid production.

The secondary metabolite phenazine-1-carboxylic acid (PCA) is an important component of the newly registered biopesticide Shenqinmycin. We used a combined method involving gene, promoter, and protein engineering to modify the central biosynthetic and secondary metabolic pathways in the PCA-producing Pseudomonas aeruginosa strain PA1201. The PCA yield of the resulting strain PA-IV was increased 54.6-fold via the following strategies: (1) blocking PCA conversion and enhancing PCA efflux pumping; (2) increasing metabolic flux towards the PCA biosynthetic pathway through the over-production of two DAHP synthases and blocking the synthesis of 21 secondary metabolites; (3) increasing the PCA precursor supply through the engineering of five chorismate-utilizing enzymes; (4) engineering the promoters of two PCA biosynthetic gene clusters. Strain PA-IV produced 9882 mg/L PCA in fed-batch fermentation, which is twice as much as that produced by the current industrial strain. Strain PA-IV was also genetically stable and comparable to Escherichia coli in cytotoxicity.

[Isolation, identification and characterization of rice rhizobacterium Pseudomonas aeruginosa PA1201 producing high level of biopesticide "Shenqinmycin" and phenazine-1-carboxamide].

OBJECTIVE: To identify bacterial strains with the inhibitory activity to rice pathogens, and to evaluate their potentials for the development of new biopesticides. METHODS: Rice rhizosphere Pseudomonas strains were isolated using 1-aminocyclopropane-1-carboxylic acid as the sole carbon source. Strain PA1201 was further identified through morphological analysis, biochemical characterization, 16S rDNA sequence analysis and phospholipid fatty acid profiling. Qualitative and quantitative analysis of the production of the green pesticide Shenqinmycin as well as phenazine-1-carboxamide produced by PA1201 was done by HPLC. Cytotoxicity of PA1201 was evaluated using human alveolar epithelial cell line A549 and Drosophila melanogaster as hosts. RESULTS: Strain PA1201 inhibited Rhizotonia solani Kuhn and Xanthomonas oryzae pv. oryzae, the causal agents of rice sheath blight and bacterial blight, respectively. It was further identified as Pseudomonas aeruginosa PA1201, which produces shenqinmycin and phenazine-1-carboxamide. The fermentation titer of shenqinmycin and phenazine-1-carboxamide in the PPM medium was 81.7 mg/L and 18. 1 mg/L, respectively. In the medium supplemented with soybean meal and corn steep liquor, the level of shenqinmycin and phenazine-1-carboxamide reached 926. 9 mg/L and 489. 5 mg/L. PA1201 also produced high level of extracellular protease and was toxic to human cell line and fruit fly. CONCLUSION: Strain PA1201 could be engineered for higher yield of Shenqinmycin or for a new biopesticide.

Tough, high conductivity pectin polysaccharide-based hydrogel for strain sensing and real-time information transmission.

Hydrogels from natural polymers are eco-friendly, biocompatible and adjustable for manufacturing wearable sensors. However, it is still challenging to prepare natural polymer hydrogel sensors with excellent properties (e.g., high conductivity). Here, we developed a physically cross-linked, highly conductive and multifunctional hydrogel (named PPTP) to address this challenge. The natural renewable pectin-based PPTP hydrogel is synthesized by introducing tannic acid (TA), calcium chloride (CaCl2), and sodium chloride (NaCl) into the pectin/polyvinyl alcohol (PVA) dual network structure. The hydrogel exhibits excellent characteristics, including unique tensile strength (2.6155 MPa), high electrical conductivity (7 S m-1), and high sensitivity (GF = 3.75). It is also recyclable, further enhancing its eco-friendly nature. The PPTP hydrogel can be used for monitoring human joint activities, as flexible electrodes for monitoring electrocardiogram (ECG) signals, and touchable screen pen for electronic skin. Moreover, when combined with Morse code and wireless Bluetooth technology, PPTP hydrogels can be used for underwater and land information encryption, and decryption. Our unique PPTP hydrogel offers promising opportunities for medical monitoring, information transfer, and human-computer interaction.

BMP4/SMAD8 signaling pathway regulated granular cell proliferation to promote follicle development in Wanxi white goose.

Granular cells proliferation in goose regulated by bone morphogenetic proteins (BMPs) signaling pathway is still unknown. In this experiment, BMPs and their receptor, and receptor activated mothers against decapentaplegic homologs (SMADs) were quantitatively expressed in granular cell layer of pre-hierarchycal and hierarchycal follicles in Wanxi White goose. The screened BMP was then used for construction of overexpressed and knockdown vectors and transfected into granular cells of goose to assess the cell proliferation and apoptosis. Granular cells with BMP-overexpressed were then used for ChIP-Seq analysis to elucidate the molecular mechanism of BMP affecting granular cell proliferation. The results showed that the mRNA expression of BMP4 was significantly expressed in pre-hierarchical follicles, and also highly expressed in hierarchical follicles than other BMPs, while the Ⅰ and Ⅱ type of BMP receptors were expressed in basic level. The mRNA expression of SMAD8 was significantly elevated in pre-hierarchical follicles. Overexpression of BMP4 could promote the proliferation of granular cells and inhibited the expression of BMP4 caused a higher cell apoptosis. ChIP-Seq identified multiple regulatory targets of SMAD4, which were mostly related to cell cycle and lipid metabolism according to the GO and KEGG pathway enrichment. From the five most significant binding motif and quantitative expression verification, the activin membrane binding inhibitor (BAMBI) was down regulated in BMP4 overexpressed granular cells. In conclusion, the BMP4 was highly expressed in granular cells and phosphorylates SMAD8, the activated SMAD8 combined with SMAD4 transfers into nucleus to regulate the expression of BAMBI to promote lipid synthesis.

Quorum sensing systems differentially regulate the production of phenazine-1-carboxylic acid in the rhizobacterium Pseudomonas aeruginosa PA1201.

Pseudomonas aeruginosa strain PA1201 is a newly identified rhizobacterium that produces high levels of the secondary metabolite phenazine-1-carboxylic acid (PCA), the newly registered biopesticide Shenqinmycin. PCA production in liquid batch cultures utilizing a specialized PCA-promoting medium (PPM) typically occurs after the period of most rapid growth, and production is regulated in a quorum sensing (QS)-dependent manner. PA1201 contains two PCA biosynthetic gene clusters phz1 and phz2; both clusters contribute to PCA production, with phz2 making a greater contribution. PA1201 also contains a complete set of genes for four QS systems (LasI/LasR, RhlI/RhlR, PQS/MvfR, and IQS). By using several methods including gene deletion, the construction of promoter-lacZ fusion reporter strains, and RNA-Seq analysis, this study investigated the effects of the four QS systems on bacterial growth, QS signal production, the expression of phz1 and phz2, and PCA production. The possible mechanisms for the strain- and condition-dependent expression of phz1 and phz2 were discussed, and a schematic model was proposed. These findings provide a basis for further genetic engineering of the QS systems to improve PCA production.