Cryptotanshinone-Doped Photothermal Synergistic MXene@PDA Nanosheets with Antibacterial and Anti-Inflammatory Properties for Wound Healing.

Humans are threatened by bacteria and other microorganisms, resulting in countless pathogen-related infections and illnesses. Accumulation of reactive oxygen species (ROS) in infected wounds activates strong inflammatory responses. The overuse of antibiotics has led to increasing bacterial resistance. Therefore, effective ROS scavenging and bactericidal capacity are essential and the advanced development of collaborative therapeutic techniques to combat bacterial infections is needed. Here, this work developes an MXene@polydopamine-cryptotanshinone (MXene@PDA-CPT) antibacterial nanosystem with excellent reactive oxygen and nitrogen species scavenging ability, which effectively inactivates drug-resistant bacteria and biofilms, thereby promoting wound healing. In this system, the adhesion of polydopamine nanoparticles to MXene produced a photothermal synergistic effect and free radical scavenging activity, presenting a promising antibacterial and anti-inflammatory strategy. This nanosystem causes fatal damage to bacterial membranes. The loading of cryptotanshinone further expanded the advantages of the system, causing a stronger bacterial killing effect and inflammation mitigatory effect with desired biosafety and biocompatibility. In addition, combining nanomaterials and active ingredients of traditional Chinese medicine, this work provides a new rationale for the future development of wound dressings, which contributes to eliminating bacterial resistance, delaying disease deterioration, and alleviating the pain of patients.

Understanding fragility and engineering activation stability in two-dimensional covalent organic frameworks.

The sensitivity of covalent organic frameworks (COFs) to pore collapse during activation processes is generally termed activation stability, and activation stability is important for achieving and maintaining COF crystallinity and porosity which are relevant to a variety of applications. However, current understanding of COF stability during activation is insufficient, and prior studies have focused primarily on thermal stability or on the activation stability of other porous materials, such as metal-organic frameworks (MOFs). In this work, we demonstrate and implement a versatile experimental approach to quantify activation stability of COFs and use this to establish a number of relationships between their pore size, the type of pore substituents, pore architecture, and structural robustness. Additionally, density functional theory calculations reveal the impact on both inter-and intra-layer interactions, which govern activation stability, and we demonstrate that activation stability can be systematically tuned using a multivariate synthesis approach involving mixtures of functionalized and unfunctionalized COF building blocks. Our findings provide novel fundamental insights into the activation stability of COFs and offer guidance for the design of more robust COFs.

Solution-Deposited and Patternable Conductive Polymer Thin-Film Electrodes for Microbial Bioelectronics.

Microbial bioelectronic devices integrate naturally occurring or synthetically engineered electroactive microbes with microelectronics. These devices have a broad range of potential applications, but engineering the biotic-abiotic interface for biocompatibility, adhesion, electron transfer, and maximum surface area remains a challenge. Prior approaches to interface modification lack simple processability, the ability to pattern the materials, and/or a significant enhancement in currents. Here, a novel conductive polymer coating that significantly enhances current densities relative to unmodified electrodes in microbial bioelectronics is reported. The coating is based on a blend of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) crosslinked with poly(2-hydroxyethylacrylate) (PHEA) along with a thin polydopamine (PDA) layer for adhesion to an underlying indium tin oxide (ITO) electrode. When used as an interface layer with the current-producing bacterium Shewanella oneidensis MR-1, this material produces a 178-fold increase in the current density compared to unmodified electrodes, a current gain that is higher than previously reported thin-film 2D coatings and 3D conductive polymer coatings. The chemistry, morphology, and electronic properties of the coatings are characterized and the implementation of these coated electrodes for use in microbial fuel cells, multiplexed bioelectronic devices, and organic electrochemical transistor based microbial sensors are demonstrated. It is envisioned that this simple coating will advance the development of microbial bioelectronic devices.

SSTDP: Supervised Spike Timing Dependent Plasticity for Efficient Spiking Neural Network Training.

Spiking Neural Networks (SNNs) are a pathway that could potentially empower low-power event-driven neuromorphic hardware due to their spatio-temporal information processing capability and high biological plausibility. Although SNNs are currently more efficient than artificial neural networks (ANNs), they are not as accurate as ANNs. Error backpropagation is the most common method for directly training neural networks, promoting the prosperity of ANNs in various deep learning fields. However, since the signals transmitted in the SNN are non-differentiable discrete binary spike events, the activation function in the form of spikes presents difficulties for the gradient-based optimization algorithms to be directly applied in SNNs, leading to a performance gap (i.e., accuracy and latency) between SNNs and ANNs. This paper introduces a new learning algorithm, called SSTDP, which bridges the gap between backpropagation (BP)-based learning and spike-time-dependent plasticity (STDP)-based learning to train SNNs efficiently. The scheme incorporates the global optimization process from BP and the efficient weight update derived from STDP. It not only avoids the non-differentiable derivation in the BP process but also utilizes the local feature extraction property of STDP. Consequently, our method can lower the possibility of vanishing spikes in BP training and reduce the number of time steps to reduce network latency. In SSTDP, we employ temporal-based coding and use Integrate-and-Fire (IF) neuron as the neuron model to provide considerable computational benefits. Our experiments show the effectiveness of the proposed SSTDP learning algorithm on the SNN by achieving the best classification accuracy 99.3% on the Caltech 101 dataset, 98.1% on the MNIST dataset, and 91.3% on the CIFAR-10 dataset compared to other SNNs trained with other learning methods. It also surpasses the best inference accuracy of the directly trained SNN with 25~32× less inference latency. Moreover, we analyze event-based computations to demonstrate the efficacy of the SNN for inference operation in the spiking domain, and SSTDP methods can achieve 1.3~37.7× fewer addition operations per inference. The code is available at: https://github.com/MXHX7199/SNN-SSTDP.

Study on the Effect of Deep Eutectic Solvent Liquid Phase Microextraction on Quality Standard, Antitussive, and Expectorant of Sangbaipi Decoction.

The SD was extracted with a new green eutectic solvent, and the extraction method of TCM decoction was developed. In the quantitative analysis by HPLC, choline chloride phenol was selected as the eutectic solvent, THF was used as the extractant, and investigation of DES type, DES molar ratio, DES-to-THF ratio, vortex time, and material-to-liquid ratio was carried out. The experimental results showed that the optimal extraction method was as follows: the molar ratio of DES was 1 : 3, and the material-liquid ratio was 5 : 1200 (mL/µL). The volume ratio of DES to THF was 1200 : 800 (µL), the vortex time was 3 min, and the extraction was repeated two times. The eutectic solvent liquid phase microextraction method was adopted to optimize the extraction method of SD and reduce the complicated processing, long time, and low efficiency of traditional methods. At the same time, in the mouse ammonia water inducing cough and phenol red excretion and expectorant experiments, SD high- and medium-dose groups have a significant inhibitory effect on the frequency of antitussive in mice and both can increase the excretion of phenol red to varying degrees, indicating that SD has good cough-relieving and expectorant effect. The present study suggests a scientific basis and basis for the clinical research and quality standard formulation of SD.

Effective Extraction of Palmatine and Berberine from Coptis chinensis by Deep Eutectic Solvents-Based Ultrasound-Assisted Extraction.

The effective components of Coptis chinensis were extracted by ultrasound-assisted technology, and the contents of palmatine and berberine were used as indexes by using Coptis chinensis as raw material and eutectic solvent as extractant. In addition, the effects of hydrogen bond donor type, molar ratio of hydrogen bond donor to acceptor, material-liquid ratio, water content of eutectic solvent system, sonication time, power, and ultrasonic temperature on the extraction rate of palmatine and berberine were studied. The optimum extraction technology of palmatine and berberine from Coptis chinensis was determined by single-factor experiment and response surface optimization test. As a result, it showed that the eutectic solvent system was constructed with choline chloride as hydrogen bond acceptor and phenol as hydrogen bond donor, with a molar ratio of 1 : 3. In addition, water content of the eutectic solvent system was 30%, ratio of material to liquid was 30 g/mL, ultrasonic time was 30 min, ultrasonic power was 200 W, and ultrasonic temperature was 60°C. At this time, the contents of palmatine and berberine in Coptis chinensis were 16.7145 mg/g and 57.4013 mg/g, respectively, which were predicted to be the same as the value, and the extraction effect was better than that of traditional extraction solvent method.

Simultaneous Determination of Six Active Components in Danggui Kushen Pills via Quantitative Analysis of Multicomponents by Single Marker.

In this paper, a valid evaluation method for the quality control of Danggui Kushen pills (DKP) has been established based on quantitative analysis of multicomponents by single marker (QAMS). Gallic acid, matrine, oxymatrine, catechin, ferulic acid, and rutin were selected as the indexes for quality evaluation of DKP. The analysis was achieved on an Agilent ZORBAX SB-C18 column (250 mm × 4.6 mm, 5 µm) via gradient elution. Gallic acid was used as internal standard to determine the relative correction factors (RCF) between gallic acid and other five constituents in DKP. The contents of those components were calculated at the same time. The accuracy of QAMS method was verified by comparing the contents of six components calculated by external standard (ES) method with those of the QAMS method. It turned out that there was no significant difference between the quantitative results of QAMS method and external standard method. The proposed QAMS method was proved to be accurate and feasible according to methodological experiments, which provided an accurate, efficient, and economical approach for quality evaluation of DKP.

CTRP6 inhibits PDGF-BB-induced vascular smooth muscle cell proliferation and migration.

Vascular smooth muscle cell (VSMC) proliferation and migration play critical roles in the development and progression of atherosclerosis. C1q/tumor necrosis factor-related protein 6 (CTRP6), a member of CTRPs family, was involved in cardiovascular diseases, inflammatory reaction and adipogenesis. However, the role of CTRP6 in VSMCs remains largely unknown. The purpose of this study is to investigate the effects of CTRP6 on VSMC proliferation and migration and explore the possible mechanism. Our results indicated that CTRP6 expression was dramatically down-regulated in human atherosclerotic tissues and in cultured VSMCs stimulated by platelet-derived growth factor-BB (PDGF-BB). In addition, CTRP6 overexpression significantly inhibited the proliferation and migration of VSMCs exposed to PDGF-BB, as well as increased expression of α-SMA and SM22α in PDGF-BB-stimulated VSMCs. Furthermore, CTRP6 overexpression efficiently prevented the activation of PI3K/Akt/mTOR in VSMCs in response to PDGF-BB. In conclusion, these findings showed that CTRP6 inhibits PDGF-BB-induced VSMC proliferation and migration, at least in part, through suppressing the PI3K/Akt/mTOR signaling pathway. Therefore, CTRP6 may be a potential target for the treatment of atherosclerosis.

[Expression and activity analysis of interferonalpha-con and thymosin-alpha1].

This study aimed to obtain recombinant fusion protein of thymosin alphal(TM-alpha1) and consensus IFNalpha (IFNalpha-con) which have bath TM-alpha1 and IFNalpha-con activities. The DNA sequence for the fusion protein was cloned into expression vector of pET-22b (+) and expressed in BL21 (DE3)-Codon plus-RP-X. The expressed product (TM-alpha1-IFN-con) was soluble, and amounted to more than 20% in total proteins of E. coli. By precipitation of (NH4)2SO4, hydrophobic interaction chromatography (HIC, Phenyl Sepharose 6 Fast Flow), anion-exchange chromatography (Q Sepharose Fast Flow), cation-exchange chromatography (SP Sepharose Fast Flow) and gel filtration (Sephadex G-75), it was purified to more than 96% purity. The activity of fusion protein for antivirus was tested by cytopathic-effect inhibition assay and activity for promoting lymphocyte proliferation was tested by cell proliferative assay. The activity for antivirus was higher than commercial IFNalpha1b and IFNalpha2a and activity for promoting lymphocyte proliferation was similar to commercial TM-alpha1. The fusion protein had better effect for anti-HBV in vitro, its effect was stronger than combination of IFNalpha and TM-alpha1 and cell toxicity was less than combination of IFNalpha and TM-alpha1. The above results show that it has effect bath antivirus of IFNalpha and promoting lymphocyte proliferation of the soluble fusion protein expressed in E. coli.