Bioorthogonal labeling and profiling of N6-isopentenyladenosine (i6A) modified RNA.

Chemical modifications in RNAs play crucial roles in diversifying their structures and regulating numerous biochemical processes. Since the 1990s, several hydrophobic prenyl-modifications have been discovered in various RNAs. Prenyl groups serve as precursors for terpenes and many other biological molecules. The processes of prenylation in different macromolecules have been extensively studied. We introduce here a novel chemical biology toolkit that not only labels i6A, a prenyl-modified RNA residue, by leveraging the unique reactivity of the prenyl group, but also provides a general strategy to incorporate fluorescence functionalities into RNAs for molecular tracking purposes. Our findings revealed that iodine-mediated cyclization reactions of the prenyl group occur rapidly, transforming i6A from a hydrogen-bond acceptor to a donor. Based on this reactivity, we developed an Iodine-Mediated Cyclization and Reverse Transcription (IMCRT) tRNA-seq method, which can profile all nine endogenous tRNAs containing i6A residues in Saccharomyces cerevisiae with single-base resolution. Furthermore, under stress conditions, we observed a decline in i6A levels in budding yeast, accompanied by significant decrease of mutation rate at A37 position. Thus, the IMCRT tRNA-seq method not only permits semi-quantification of i6A levels in tRNAs but also holds potential for transcriptome-wide detection and analysis of various RNA species containing i6A modifications.

Skin-Friendly Flexible Ultraviolet Detectors Based on Reversibly Deformable Worm-Like Polymer Nanoparticles.

Flexible ultraviolet (UV) light detection technology has important applications in wearable devices, smart sensors, and other fields and attracts much attention in recent years. However, for most semiconductor-based UV detectors, the elastic modulus between rigid semiconductors and flexible substrates is mismatched, which makes it difficult to fabricate UV detectors that meet the needs of wearable devices. Herein, a fully flexible, large-scale, skin-friendly UV photodetector component centered on photo-responsive worm-like polymer nanoparticles (NPs) is developed, and the resulting device can quantitatively detect UV illumination. Skin-friendly poly(vinyl alcohol) (PVA), amphiphilic azobenzene-containing polymer NPs (AzNPs), and water-soluble ionic liquids (IL) are formed into (AzNPs-IL)/PVA fabrics by electrospinning. There are interactions such as hydrogen bonding among PVA, AzNPs, and IL, which make the material system stable. The UV detector made of the fabric realizes UV sensing through the illuminance-mechanical stress-electrical signal conversion mechanism. It is capable of achieving a response time of 9 s, a detection range of 10-150 mW cm-2, and stability for 1000 cycle tests upon 365 nm UV irradiation. Moreover, it has good skin affinity, and the water contact angle of the fabric is only 23.57°, which holds great promise for wearable smart devices.

Infection microenvironment-triggered nanoparticles eradicate MRSA by thermally amplified chemodynamic therapy and M1 macrophage.

It is of great significance to develop a novel approach to treat bacterial infections, as the frequent misuse of antibiotics leads to the serious problem of bacterial resistance. This study proposed antibiotic-free antibacterial nanoparticles for eliminating methicillin-resistant Staphylococcus aureus (MRSA) based on a multi-model synergistic antibacterial ability of chemodynamic therapy (CDT), photothermal effect, and innate immunomodulation. Specifically, a polydopamine (PDA) layer coated and Ag nanoparticles loaded core-shell structure Fe3O4 nanoparticles (Fe3O4@PDA-Ag) is prepared. The Fe3O4 catalyzes H2O2 present in acidic microenvironment of bacterial infection into more toxic reactive oxygen species (ROS) and synergizes with the released Ag ions to exert a stronger bactericidal capacity, which can be augmented by photothermal action of PDA triggered by near-infrared light and loosen the biofilm by photothermal action to promote the penetration of ROS and Ag ion into the biofilm, result in disrupting biofilm structure along with killing encapsulated bacteria. Furthermore, Fe3O4@PDA-Ag exerts indirect antibacterial effects by promoting M1 macrophage polarizing. Animal models demonstrated that Fe3O4@PDA-Ag effectively controlled MRSA-induced infections through photothermal enhanced CDT, Ag+ releasing, and macrophage-mediated bactericidal properties. The acid-triggered antibacterial nanoparticles are expected to combat drug-resistant bacteria infection.

Effects of oral carbohydrate loading in patients scheduled for painless bidirectional endoscopy: a prospective randomized controlled trial.

PURPOSE: Traditional fasting causes considerable discomfort without added assurance of security, whereas oral carbohydrate beverage offers an alternative to improve medical experience. This study aims to explore the impact of different types and dosages of oral fluids loading before painless bidirectional endoscopy on the gastric emptying and wellbeing. METHODS: 180 patients arranged for bidirectional endoscopy with intravenous anesthesia were randomized: patients in the control group (Group C) obeyed standard fasting; the 200 mL carbohydrate group (Group P1), 400 mL carbohydrate group (Group P2), 200 mL water group (Group W1) and 400 mL water group (Group W2) respectively consumed 200 mL or 400 mL corresponding clear liquids 2 h before the procedure. Gastric emptying metrics under ultrasound, subjective comfort indexes, periprocedural blood glucose and vital signs were contrasted among the groups. RESULTS: No significant differences were detected in the gastric emptying including CSA (cross-sectional area), GV (gastric volume), cGV (corrected gastric volume) and the three-point grading system among groups, and none had a cGV > 1.5 mL/kg before anesthesia. Participants in Group P2 experienced less preprocedural thirst and mouth dryness, so as the postprocedural thirst, mouth dryness and hunger. Periprocedural blood glucose and MAP had the similar trend in all groups. The occurrence of hypotension, bradycardia, hypoxia, and the required norepinephrine was comparable among the groups. CONCLUSIONS: Oral beverage loading with 200 mL or 400 mL can be safely applicated 2 h before painless bidirectional endoscopy without increasing the gastric volume. 400 mL carbohydrate solution effectively relieves the discomfort and could serve as a consideration. TRIAL REGISTRATION: Registered in the Chinese Clinical Trial Registry on December 5, 2023 (ChiCTR2300078319).

Efficient treatment of colon cancer with codelivery of TRAIL and imatinib by liposomes.

To solve the problem of resistance of tumor cells to TRAIL and the inevitable side effects of imatinib during treatment, we successfully prepared a kind of multifunctional liposome that encapsulated imatinib in its internal water phase and inserted TRAIL on its membrane in this study, which named ITLPs. The liposomes appeared uniform spherical and the particle size was approximately 150 nm. ITLPs showed high accumulation in TRAIL-resistance cells and HT-29 tumor-bearing mice model. In vitro cytotoxicity assay results showed that the killing activity of HT-29 cells treated with ITLPs increased by 50% and confirmed that this killing activity was mediated by the apoptosis pathway. Through mechanism studies, it was found that ITLPs arrested up to 32.3% of cells in phase M to exert anti-tumor effects. In vivo anti-tumor study showed that ITLPs achieved 61.8% tumor suppression and little toxicity in the HT-29 tumor-bearing mice model. Overall results demonstrated that codelivery of imatinib and TRAIL via liposomes may be a prospective method in the treatment of the TRAIL-resistance tumor.

A cost-effectiveness analysis of fluoride varnish application in preventing Root caries in elderly persons: a Markov simulation study.

BACKGROUND: Root caries are prevalent issues that affect dental health, particularly among elderly individuals with exposed root surfaces. Fluoride therapy has shown effectiveness in preventing root caries, but limited studies have addressed its cost-effectiveness in elderly persons population. This study aimed to evaluate the cost-effectiveness of a fluoride treatment program for preventing root caries in elderly persons within the context of Chinese public healthcare. METHODS: A Markov simulation model was adopted for the cost-effectiveness analysis in a hypothetical scenario from a healthcare system perspective. A 60-year-old subject with 23 teeth was simulated for 20 years. A 5% sodium fluoride varnish treatment was compared with no preventive intervention in terms of effectiveness and cost. Tooth years free of root caries were set as the effect. Transition probabilities were estimated from the data of a community-based cohort and published studies, and costs were based on documents published by the government. The incremental cost-effectiveness ratio (ICER) was calculated to evaluate cost-effectiveness. Univariate and probabilistic sensitivity analyses were performed to evaluate the influence of data uncertainty. RESULTS: Fluoride treatment was more effective (with a difference of 10.20 root caries-free tooth years) but also more costly (with a difference of ¥1636.22). The ICER was ¥160.35 per root caries-free tooth year gained. One-way sensitivity analysis showed that the risk ratio of root caries in the fluoride treatment group influenced the result most. In the probabilistic sensitivity analysis, fluoride treatment was cost-effective in 70.5% of the simulated cases. CONCLUSIONS: Regular 5% sodium fluoride varnish application was cost-effective for preventing root caries in the elderly persons in most scenarios with the consideration of data uncertainty, but to a limited extent. Improved public dental health awareness may reduce the incremental cost and make the intervention more cost-effective. Overall, the study shed light on the economic viability and impact of such preventive interventions, providing a scientific basis for dental care policies and healthcare resource allocation.

[Preparation of hybrid exosomes based on bovine milk exosomes and liposomes and pharmacodynamic study of sinomenine loaded exosomes in treatment of rheumatoid arthritis].

This study investigates the therapeutic effect of hybrid exosomes loaded with sinomenine(SIN) obtained by membrane fusion of milk exosomes with liposomes in collagen-induced arthritis(CIA) rats. Exosomes were isolated from fresh bovine milk by sucrose density gradient centrifugation, while liposomes were prepared using the emulsion solvent evaporation-low temperature curing method. Hybrid exosomes were characterized after membrane fusion through co-incubation: The morphology was detected by transmission electron microscopy, the particle size and potential by nanoparticle size potentiostat, and the expressions of surface characteristic proteins CD63 and TSG101 before and after fusion by Western blot(WB). The drug loading capacity and encapsulation rate of sinomenine were measured after the loading of sinomenine on exosomes by ultrasonic method. The CIA rat model was induced by collagen antibody. The efficacy experiment consisted of the control group, model group, SIN group, SIN-liposome group, SIN-milk exosome group, SIN-hybrid exosome group and positive drug(dexamethasone) group. The changes in body mass of rats during administration were recorded. Besides, the foot swelling, immune organ index, arthritis index, microcirculation index, synovial histopathology, and serum inflammatory factor levels detected by enzyme-linked immunosorbent assay were observed for pharmacodynamical study. Under transmission electron microscopy, both hybrid exosomes and milk exosomes showed saucer-like appearance. After co-incubation, the exosome particle size increased from(97.92±3.42)nm to(132.70±4.07)nm, and the Zeta potential changed from(-2.01±0.33)mV to(-17.90±2.13)mV. WB assay showed that CD63 and TSG101 proteins were normally expressed in milk exosomes and hybrid exosomes. The encapsulation rate of milk exosomes was 31.64%±2.48%, with a drug loading of 2.35%±0.52%, while the hybrid exosomes exhibited an encapsulation rate of 48.21%±3.12% and drug loading of 3.17%±0.36%, as determined by the microplate reader. Pharmacodynamic results showed that compared with the model group, the general condition, swelling degree of foot, arthritis index and immune organ index of all drug administration groups were significantly improved(P<0.05, P<0.01); microvascular comprehensive score and vascular resistance were significantly decreased(P<0.05, P<0.01); serum levels of TNF-α, IL-1ß and IL-6 inflammatory factors were significantly decreased(P<0.01); and the lesions of synovial tissue were improved to some extent. Meanwhile, compared with the SIN group, SIN-liposome group and SIN-milk exosome group, the SIN-hybrid exosome group had a more stable and durable drug effect. The hybrid exosomes obtained by co-incubation of milk-derived exosomes with liposomes successfully improved the drug carrying capacity of exosomes and biocompatibility of liposomes. The hybrid exosomes loaded with sinomenine have good efficacy on CIA model rats, and can effectively solve the problems of TCM such as sinomenine, which have good efficacy but short biological half-life. The study provides new insights for the development of TCM and the treatment of diseases such as rheumatoid arthritis.

Antitumor activity of pegylated human interferon ß as monotherapy or in combination with immune checkpoint inhibitors via tumor growth inhibition and dendritic cell activation.

Type I interferons (IFN), especially human IFN alpha (IFNα), have been utilized for antitumor therapy for decades. Human interferon beta (IFNß) is rarely used for cancer treatment, despite advantages over IFNα in biological activities such as tumor growth inhibition and dendritic cell (DC) activation. The utilization of pegylated human IFNß (PEG-IFNß), as monotherapy or in combination with immune checkpoint inhibitors (ICIs) was evaluated in this study through in vivo efficacy studies in syngeneic mouse melanoma, non-small cell lung cancer (NSCLC), and colon adenocarcinoma (COAD) models resistant to immune checkpoint inhibitors (ICIs). In vitro comparative study of PEG-IFNß and pegylated IFNα-2b was performed in terms of tumor growth inhibition against human melanoma, NSCLC and COAD cell lines and activation of human monocyte-derived DCs (MoDCs). Our data demonstrate that the in vivo antitumor effects of PEG-IFNß are partially attributable to tumor growth-inhibitory effects and DC-activating activities, superior to pegylated IFNα-2b. Our findings suggest that utilizing PEG-IFNß as an antitumor therapy can enhance the therapeutic effect of ICIs in ICI-resistant tumors by directly inhibiting tumor growth and induction of DC maturation.

Codelivery of TRAIL and Mitomycin C via Liposomes Shows Improved Antitumor Effect on TRAIL-Resistant Tumors.

Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) constitutes a promising antitumor drug, tumor resistance to TRAIL has become a major obstacle in its clinical application. Mitomycin C (MMC) is an effective TRAIL-resistant tumor sensitizer, which indicates a potential utility of combination therapy. However, the efficacy of this combination therapy is limited owing to its short half-life and the cumulative toxicity of MMC. To address these issues, we successfully developed a multifunctional liposome (MTLPs) with human TRAIL protein on the surface and MMC encapsulated in the internal aqueous phase to codeliver TRAIL and MMC. MTLPs are uniform spherical particles that exhibit efficient cellular uptake by HT-29 TRAIL-resistant tumor cells, thereby inducing a stronger killing effect compared with control groups. In vivo assays revealed that MTLPs efficiently accumulated in tumors and safely achieved 97.8% tumor suppression via the synergistic effect of TRAIL and MMC in an HT-29 tumor xenograft model while ensuring biosafety. These results suggest that the liposomal codelivery of TRAIL and MMC provides a novel approach to overcome TRAIL-resistant tumors.

A GP130-Targeting Small Molecule, LMT-28, Reduces LPS-Induced Bone Resorption around Implants in Diabetic Models by Inhibiting IL-6/GP130/JAK2/STAT3 Signaling.

In this study, we examined the effect of the GP130-targeting molecule, LMT-28, on lipopolysaccharide- (LPS-) induced bone resorption around implants in diabetic models using in vitro and rat animal experiments. First, LMT-28 was added to osteoblasts stimulated by LPS and advanced glycation end products (AGEs), and nuclear factor-κB receptor-activating factor ligand (RANKL) and associated pathways were evaluated. Then, LMT-28 was administered by gavage at 0.23 mg/kg once every 5 days for 2 weeks to type 2 diabetic rats with peri-implantitis induced by LPS injection and silk ligature. The expression of IL-6 and RANKL was evaluated by immunohistochemistry, and the bone resorption around implants was evaluated by microcomputed tomography. The results showed that LMT-28 downregulated the expression of RANKL through the JAK2/STAT3 signaling pathway in osteoblasts stimulated by LPS and AGEs, reduced bone resorption around implants with peri-implantitis, decreased the expression of IL-6 and RANKL, and decreased osteoclast activity in type 2 diabetic rats. This study confirmed the ability of LMT-28 to reduce LPS-induced bone resorption around implants in diabetic rats.

Fruit Rot Caused by Fusarium sulawesiense on Chilli in Guangxi, China.

Chilli (Capsicum annuum) is considered as one of the most important vegetables and spice crops throughout the world which is widely cultivated in China. In October 2019, fruit rot symptoms were observed on chilli in Guilin, Guangxi, China (N24°18', E109°45'). Irregular dark green spots initially appeared on the middle or bottom of the fruit, then extended to larger grayish brown lesions and started to rot. In the late stage, the whole fruit dried up after water loss. Three disease samples were collected from three towns of different counties in Guilin where the disease incidence of chilli fruits was 15-30%. The margin of diseased fruits was cut into small pieces (3×3 mm), disinfected with 75% ethanol solution for 10 s, 2% NaOCl for 1 min, and rinsed in sterile distilled water three times. Tissue pieces were separately plated on potato dextrose agar (PDA) and incubated at 25°C for seven days. Fifty-four fungal isolates with similar morphology were consistently recovered from diseased tissues of three fruits, with 100% isolation frequency. Three representatives GC1-1, GC2-1 and PLX1-1 were selected for further analysis. The colonies produced abundant whitish to yellowish aerial mycelium on PDA after 7 days incubation at 25°C in the dark. Macroconidia cultured on carnation leaf agar (CLA) for 7 days were long, hyaline, falcate, with dorsal and ventral lines often gradually wider toward apex, curved apical cell and foot-shaped basal cell, mostly 2 to 5 septa, and ranged from 24.16 to 38.88 × 3.36 to 6.55 µm (average 31.39×4.48 µm), from 19.44 to 28.68 × 3.02 to 4.99 µm (average 23.02×3.89 µm), and from 20.96 to 35.05 × 3.30 to 6.06 µm (average 26.24×4.51 µm) for GC1-1, GC2-1, and PLX1-1, respectively. Microconidia were hyaline, fusoid or ovoid, one-septate or nonseptate, and ranged from 4.61 to 10.14 × 2.61 to 4.77 µm (average 8.13×3.58 µm), from 3.55 to 7.85 × 1.95 to 3.04 µm (average 5.79×2.39 µm), and from 6.75 to 18.48 × 3.05 to 9.07 µm (average 14.32×4.31 µm) for GC1-1, GC2-1, and PLX1-1, respectively. Genomic DNA was extracted from 7-day-old aerial mycelia of these isolates. The internal transcribed spacer (ITS), translation elongation factor (TEF1), calmodulin (CAM) and partial RNA polymerase second largest subunit (RPB2) were amplified using primers ITS4/ITS1, EF1/EF2, CL1/CL2A, and 5F2/7cR, respectively (White et al. 1990; O'Donnell et al. 2000, 2010). Sequences were deposited in GenBank (ITS: OQ080044-OQ080046; TEF1: OQ101589-OQ101591; CAM: OQ101586-OQ101588; RPB2: OQ101592-OQ101594). A maximum Likelihood (ML) phylogenetic tree was constructed with RAxML version 8.2.10 based on the concatenated sequences (ITS, CAM, TEF1, RPB2). According to morphology and phylogenetic analysis, the isolates were identified as Fusarium sulawesiense (Maryani et al. 2019). For pathogenicity tests, multiple punctures in a 5-mm-diameter circle were made with a sterilized toothpick on detached young healthy fruits, followed by inoculation with 10 µl of conidial suspension (106 spores/ml in 0.1% sterile Tween 20). Each isolate was inoculated onto eighteen fruits. Controls were inoculated with water containing 0.1% sterile Tween 20 under the same conditions. Symptoms were observed on the inoculated fruits 7 days after incubation at 25°C, whereas non-inoculated controls were asymptomatic. The fungus was re-isolated from inoculated chilli fruits, completing Koch's postulates. To our knowledge, this is the first report of Fusarium sulawesiense causing fruit rot on Chilli in China. These results will provide valuable information for prevention and management of fruit rot on Chilli.

Effect of quorum quenching on biofouling control and microbial community in membrane bioreactors by Brucella sp. ZJ1.

Quorum quenching (QQ) has been demonstrated to be a novel technique for controlling biofouling in membrane bioreactors (MBRs), as it can significantly inhibit biofilm formation by disrupting quorum sensing (QS). The exploration of new QQ bacterial strains and the evaluation of their performance in mitigating membrane fouling in MBR systems is significant. In this study, an efficient QQ strain, Brucella sp. ZJ1 was encapsulated in alginate beads and evaluated for its ability to mitigate biofouling. The findings revealed that MBR with QQ beads extended the operation time by 2-3 times without affecting pollutant degradation. QQ beads maintained approximately 50% QQ activity after more than 50 days operation, indicating a long-lasting and endurable QQ effect. The QQ effect reduced extracellular polymeric substance (EPS) production especially in terms of polysaccharide and protein by more than 40%. QQ beads in the MBR also reduced the cake resistance and the irreversible resistance of membrane biofouling. Metagenomic sequencing suggests that QQ beads suppressed the QS effect and increased the abundance of QQ enzyme genes, ultimately inducing efficient membrane biofouling control.

Liposome-Based Co-Immunotherapy with TLR Agonist and CD47-SIRPα Checkpoint Blockade for Efficient Treatment of Colon Cancer.

Antitumor immunity is an essential component of cancer therapy and is primarily mediated by the innate immune response, which plays a critical role in initiating and shaping the adaptive immune response. Emerging evidence has identified innate immune checkpoints and pattern recognition receptors, such as CD47 and Toll-like receptor 7 (TLR7), as promising therapeutic targets for cancer treatment. Based on the fusion protein Fc-CV1, which comprises a high-affinity SIRPα variant (CV1), and the Fc fragment of the human IgG1 antibody, we exploited a preparation which coupled Fc-CV1 to imiquimod (TLR7 agonist)-loaded liposomes (CILPs) to actively target CT26. WT syngeneic colon tumor models. In vitro studies revealed that CILPs exhibited superior sustained release properties and cell uptake efficiency compared to free imiquimod. In vivo assays proved that CILPs exhibited more efficient accumulation in tumors, and a more significant tumor suppression effect than the control groups. This immunotherapy preparation possessed the advantages of low doses and low toxicity. These results demonstrated that a combination of immune checkpoint blockade (ICB) therapy and innate immunity agonists, such as the Fc-CV1 and imiquimod-loaded liposome preparation utilized in this study, could represent a highly effective strategy for tumor therapy.

Effects of different designs of orthodontic clear aligners on the maxillary central incisors in the tooth extraction cases: a biomechanical study.

BACKGROUND: Controlling the 3D movement of central incisors during tooth extraction cases with clear aligners is important but challenging in invisible orthodontic treatment. This study aimed to explore the biomechanical effects of central incisors in tooth extraction cases with clear aligners under different power ridge design schemes and propose appropriate advice for orthodontic clinic. METHODS: A series of Finite Element models was constructed to simulate anterior teeth retraction or no retraction with different power ridge designs. These models all consisted of maxillary dentition with extracted first premolars, alveolar bone, periodontal ligaments and clear aligner. And the biomechanical effects were analysed and compared in each model. RESULTS: For the model of anterior teeth retraction without power ridge and for the model of anterior teeth no retraction with a single power ridge, the central incisors exhibited crown lingual inclination and relative extrusion. For the model of anterior teeth no retraction with double power ridges, the central incisors tended to have crown labial inclination and relative intrusion. For the model of anterior tooth retraction with double power ridges, the central incisors exhibited a similar trend to the first kind of model, but as the depth of the power ridge increased, there was a gradual decrease in crown retraction value and an increase in crown extrusion value. The simulated results showed that von-Mises stress concentration was observed in the cervical and apical regions of the periodontal ligaments of the central incisors. The clear aligner connection areas of adjacent teeth and power ridge areas also exhibited von-Mises stress concentration and the addition of power ridge caused the clear aligner to spread out on the labial and lingual sides. CONCLUSIONS: The central incisors are prone to losing torque and extruding in tooth extraction cases. Double power ridges have a certain root torque effect when there are no auxiliary designs, but they still cannot rescue tooth inclination during tooth retraction period. For tooth translation, it may be a better clinical procedure to change the one-step aligner design to two-step process: tilting retraction and root control.

[Research Advances in Medical Materials and Products for Soft Tissue Repairs].

Soft tissue is an indispensable tissue in human body. It plays an important role in protecting the body from external physical, chemical or biological factors. Mild soft tissue injuries can self-heal, while severe soft tissue injuries may require related treatment. Natural polymers (such as chitosan, hyaluronic acid, and collagen) and synthetic polymers (such as polyethylene glycol and polylactic acid) exhibit good biocompatibility, biodegradability and low toxicity. It can be used for soft tissue repairs for antibacterial, hemostatic and wound healing purposes. Their related properties can be enhanced through modification or preparation of composite materials. Commonly used soft tissue repairs include wound dressings, biological patches, medical tissue adhesives, and tissue engineering scaffolds. This study introduces the properties, mechanisms of action and applications of various soft tissue repair medical materials, including chitosan, hyaluronic acid, collagen, polyethylene glycol and polylactic acid, and provides an outlook on the application prospects of soft tissue repair medical materials and products.

Rapid Regulation of Local Temperature and Transient Receptor Potential Vanilloid 1 Ion Channels with Wide-Field Plasmonic Thermal Microscopy.

Plasmonic absorption of light can create significant local heat and has become a promising tool for rapid temperature regulation in diverse fields, from biomedical technology to optoelectronics. Current plasmonic heating usually relies on specially designed nanomaterials randomly distributed in the space and barely provides uniform temperature regulation in a wide field. Herein, we report a rapid temperature regulation strategy on a plain gold-coated glass slip using a plasmonic scattering microscopy, which can be referred to as wide-field plasmonic thermal microscopy (W-PTM). We calibrated the W-PTM by monitoring the phase transition of the temperature-sensitive polymer solutions, showing that it can provide a temperature regulation range of 33-80 °C. Moreover, the W-PTM provides imaging capability, thus allowing the statistical analysis of the phase-transitioned polymeric nanoparticles. Finally, we demonstrated that W-PTM can be used for noninvasive and local regulation of the transient receptor potential vanilloid 1 (TRPV1) ion channels in the living cells, which can be monitored by simultaneous fluorescence imaging of the calcium influx. With the nondestructive local temperature-regulating and concurrent fluorescence imaging capability, we anticipate that W-PTM can be a powerful tool to study cellular activities associated with cellular membrane temperature changes.

Bending-Insensitive Intrinsically Flexible Ultraviolet Encoding Devices Based on Piezoelectric Nanogenerator-Supplied Liquid Crystalline Polymer Fabrics.

It is significantly challenging for state-of-the-art wearable electronics to stably monitor physicochemical signals under dynamic motions. Herein, a bending-insensitive, self-powered, and intrinsically flexible UV detector has been realized based on well-designed oriented composite fabrics, consisting of ionic liquid (IL)-containing liquid crystalline polymers (ILCPs) and piezoelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] nanogenerators. The novel composite fabrics establish effective UV illuminance-internal stress-electric signal conversion by coupling resistive and piezoelectric effects, with a fast response time of 190 ms. Particularly, benefiting from the intrinsic flexibility of composite fabrics, the ILCP/P(VDF-TrFE) device can maintain stable performance under dynamic bending even if the frequency is up to 2.5 Hz, with a bending insensitivity of less than 1% performance variation under 1.0 mW cm-2 UV light. Combined with the Internet of Things and the American Standard Code for Information Interchange (ASCII), wearable encoding electronics have been successfully implemented with a printing speed of 3.2 s per character under dynamic bending.

Loss of THIN EXINE2 disrupts multiple processes in the mechanism of pollen exine formation.

Exine, the sporopollenin-based outer layer of the pollen wall, forms through an unusual mechanism involving interactions between two anther cell types: developing pollen and tapetum. How sporopollenin precursors and other components required for exine formation are delivered from tapetum to pollen and assemble on the pollen surface is still largely unclear. Here, we characterized an Arabidopsis (Arabidopsis thaliana) mutant, thin exine2 (tex2), which develops pollen with abnormally thin exine. The TEX2 gene (also known as REPRESSOR OF CYTOKININ DEFICIENCY1 (ROCK1)) encodes a putative nucleotide-sugar transporter localized to the endoplasmic reticulum. Tapetal expression of TEX2 is sufficient for proper exine development. Loss of TEX2 leads to the formation of abnormal primexine, lack of primary exine elements, and subsequent failure of sporopollenin to correctly assemble into exine structures. Using immunohistochemistry, we investigated the carbohydrate composition of the tex2 primexine and found it accumulates increased amounts of arabinogalactans. Tapetum in tex2 accumulates prominent metabolic inclusions which depend on the sporopollenin polyketide biosynthesis and transport and likely correspond to a sporopollenin-like material. Even though such inclusions have not been previously reported, we show mutations in one of the known sporopollenin biosynthesis genes, LAP5/PKSB, but not in its paralog LAP6/PKSA, also lead to accumulation of similar inclusions, suggesting separate roles for the two paralogs. Finally, we show tex2 tapetal inclusions, as well as synthetic lethality in the double mutants of TEX2 and other exine genes, could be used as reporters when investigating genetic relationships between genes involved in exine formation.

Bioinspired Polysaccharide Derivative with Efficient and Stable Lubrication for Silicon-Based Devices.

It is becoming increasingly important to synthesize efficient biomacromolecule lubricants suitable for medical devices. Even though the development of biomimetic lubricants has made great progress, the current system suitable for hydrophobic silicone-based medical devices is highly limited. In this work, we synthesize one kind of novel polysaccharide-derived macromolecule lubricant of chitosan (CS) grafted polyethylene glycol (PEG) chains and catechol groups (CT) (CS-g-PEG-g-CT). CS-g-PEG-g-CT shows good adsorption ability by applying quantitative analysis of quartz crystal microbalance (QCM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and confocal fluorescence imaging technique, as well as the typical shear-thinning feature. CS-g-PEG-g-CT exhibits low and stable coefficients of friction (COFs) (0.01-0.02) on polydimethylsiloxane (PDMS) surfaces at a wide range of mass concentrations in diverse media including pure water, physiological saline, and PBS buffer solution and is even tolerant to various normal loads and sliding frequencies for complex pressurizing or shearing environments. Subsequently, systematic surface characterizations are used to verify the dynamic attachment ability of the CS-g-PEG-g-CT lubricant on the loading/shearing process. The lubrication mechanism of CS-g-PEG-g-CT can be attributed to the synergy of strong adsorption from catechol groups to form a uniform assembly layer, excellent hydration effect from PEG chains, and typical shear-thinning feature to dissipate viscous resistance. Surprisingly, CS-g-PEG-g-CT exhibits efficient lubricity on silicone-based commercial contact lenses and catheters. The current macromolecule lubricant demonstrates great real application potential in the fields of medical devices and disease treatments.

Development of Biocompatible Ene-Ligation Enabled by Prenyl-Based ß-Caryophyllene with Triazoline/Selectfluor under Physiological Conditions.

Here, we first report a rapid and highly selective biocompatible ligation that proceeds via a strain-promoted prenyl-involved [2, 3]-Ene rearrangement process. We demonstrate the usefulness of naturally occurring strain-promoted ß-caryophyllene with triazoline (PTAD)/Selectfluor in the study of tagging molecule-of-interest. Experiments in peptide (Histone H3 (1-21) and Myhc (614-629)) and protein (BSA, ßLG, and HSP40) models exemplified the utility of the Ene-ligation for in vivo imaging and tracking.