Gold nanoclusters stabilized with dopa-containing ligands: Catalyst-indicator integrated probe for tumor cell screening.

Elevated hydrogen peroxide (H2O2) levels not only inflict cellular damage but also serve as a harbinger for various diseases. Tumor cells, in particular, often exhibit an abundance of H2O2. Hence, the detection of this pivotal molecule assumes paramount importance in monitoring physiological states and expediting cancer diagnosis. To this end, we have ingeniously devised an enzyme-free and monomeric system for intracellular H2O2 detection. Our astute selection of dopa-containing peptidomimetics, replete with ortho-bisphenol and amino acid moieties, has engendered the synthesis of distinctive fluorescent gold nanoclusters (AuNCs). These nanoclusters not only function as a peroxidase-like catalyst, catalyzing the decomposition of H2O2 into hydroxyl radicals (·OH), but also serve as an indicator, with their fluorescence quenched in response to varying H2O2 concentrations. Experimental results evince that our GDpE-AuNCs exhibit remarkable sensitivity, boasting a detection limit of 0.49 µM and a linear range of 5-1000 µM. Moreover, the amalgamation of catalyst and indicator within a single structure, facilitating efficient cellular uptake, engenders intracellular H2O2 detection and discernment of tumor cells. This pioneering approach bequeaths a valuable assay probe for monitoring physiological states and ushering in early disease diagnosis.

[Discussion on reference sample research of traditional Chinese medicine compound preparations developed from catalogued ancient classical prescriptions].

The concept of reference sample was put forward in the Guidance on CMC of Traditional Chinese Medicine Compound Preparations Developed from Catalogued Ancient Classical Prescriptions(Interim). The research on reference sample is a key link in the research and development of traditional Chinese medicine(TCM) compound prescriptions from catalogued ancient classical prescriptions(known as Category 3.1 TCM). This paper discusses the content of research on reference sample by analyzing the characteristics of Category 3.1 TCM and the purpose of research on reference sample. Furthermore, suggestions on the research of reference sample are proposed according to the development and evaluation practice of Category 3.1 TCM and research achievements of TCM regulatory science, aiming to provide reference for colleagues in this industry.

An injectable collagen peptide-based hydrogel with desirable antibacterial, self-healing and wound-healing properties based on multiple-dynamic crosslinking.

Conventional collagen-based hydrogels as wound dressing materials are usually lack of antibacterial activity and easily broken when encountering external forces. In this work, we developed a collagen peptide-based hydrogel as a wound dressing, which was composed of adipic acid dihydrazide functionalized collagen peptide (Col-ADH), oxidized dextran (ODex), polyvinyl alcohol (PVA) and borax via multiple-dynamic reversible bonds (acylhydrazone, amine, borate ester and hydrogen bonds). The injectable hydrogel exhibited satisfactory self-healing ability, antibacterial activity, mechanical strength, as well as good biocompatibility and biodegradability. In vivo experiments demonstrated the rapid hemostasis, accelerated cell migration, and promoted wound healing capacities of the hydrogel. These results indicate that the multifunctional collagen peptide-based hydrogel has great potentials in the field of wound dressings.

[Research progress and maturity assessment of continuous manufacturing of traditional Chinese medicine].

The pharmaceutical manufacturing model is gradually changing from intermittent manufacturing to continuous manufacturing and intelligent manufacturing. This paper briefly reviewed the supervision and research progress in continuous pharmaceutical manufacturing in China and abroad and described the definition and advantages of continuous pharmaceutical manufacturing. The continuous manufacturing of traditional Chinese medicine(TCM) at the current stage was summarized in the following three terms: the enhancement of the continuity of intermittent manufacturing operations, the integration of continuous equipment to improve physical continuity between units, and the application of advanced process control strategies to improve process continuity. To achieve continuous manufacturing of TCM, the corresponding key technologies, such as material property characterization, process modeling and simulation, process analysis technology, and system integration, were analyzed from the process and equipment, respectively. It was proposed that the continuous manufacturing equipment system should have the characteristics of high speed, high response, and high reliability, "three high(H~3)" for short. Considering the characteristics and current situation of TCM manufacturing, based on the two dimensions of product quality control and production efficiency, a maturity assessment model for continuous manufacturing of TCM, consisting of operation continuity, equipment continuity, process continuity, and quality control continuity, was proposed to provide references for the application of continuous manufacturing technology for TCM. The implementation of continuous manufacturing or the application of key continuous manufacturing technologies in TCM can help to systematically integrate advanced pharmaceutical technology elements and promote the uniformity of TCM quality and the improvement of production efficiency.

Sub-50 nm core-shell nanoparticles with the pH-responsive squeezing release effect for targeting therapy of hepatocellular carcinoma.

The development of drug delivery systems with high drug loading capacity, low leakage at physiological pH, and rapid release at the lesion sites remains an ongoing challenge. In this work, core-shell poly(6-O-methacryloyl-D-galactose)@poly(tert-butyl methacrylate) (PMADGal@PtBMA) nanoparticles (NPs) of sub-50 nm are facilely synthesized by reversible addition-fragmentation chain transfer (RAFT) soap-free emulsion polymerization with the assistance of 12-crown-4. A hydrophilic poly(methacrylic acid) (PMAA) core can then be revealed after deprotection of the tert-butyl groups, which is negatively charged and can adsorb nearly 100% of incubated doxorubicin (DOX) from a solution at pH 7.4. The physical shrinkage of PMAA chains below pH 6.0 endows the core with the squeezing effect, therefore realizing rapid drug release. It is demonstrated that the DOX release rate of PMADGal@PMAA NPs at pH 5 was 4 times that at pH 7.4. Cellular uptake experiments confirm the high targeting ability of the galactose modified PMADGal shell to human hepatocellular carcinoma (HepG2) cells. The fluorescence intensity of DOX in HepG2 cells is 4.86 times that of HeLa cells after 3 h incubation. Moreover, 20% cross-linked NPs show the highest uptake efficiency by HepG2 cells due to their moderate surface charge, size and hardness. In summary, both the core and the shell of PMADGal@PMAA NPs promise the rapid site-specific release of DOX in HepG2 cells. This work provides a facile and an effective strategy to synthesize core-shell NPs for hepatocellular carcinoma targeting therapy.

Galactosylated Core-Shell Nanoparticles with pH/GSH Dual Sensitivity for Targeting Hepatocellular Carcinoma.

Galactosylated core-shell nanoparticles (NPs) with diameters of sub-50 nm were fabricated in one pot by reversible addition-fragmentation chain transfer (RAFT) soap-free emulsion polymerization. Their galactosylated shells and acidic cores endow them with high targeting and drug loading efficiencies, respectively. Morever, the physical shrinkage and cleavage of the disulfide cross-linked NPs can realize the rapid release of loaded doxorubicin (DOX) under pH 5.0 and reduced glutathione (GSH) conditions. The combination of these excellent properties resulted in an even lower IC50 of DOX-loaded NPs than free DOX, demonstrating that this platform would be promising in targeting the therapy of hepatocellular carcinoma.

Controllable assembly of high sticky and flexibility surface-enhanced Raman scattering substrate for on-site target pesticide residues detection.

Pesticide residues in fruit and vegetable constitute a great threat to mankind's health, and a technique of rapid, cost-effective, ultra-sensitive and non-destructive analysis is especially critical for on-site detection in practical application. A strategy was utilized to fabricate highly viscous and flexible WPU@AgNPs sticky tape for the rapid extraction and Surface-enhanced Raman Scattering (SERS) assay of thiabendazole residues on the surface of fruits. Simply put, the novel WPU@AgNPs tapes were constructed by decorating the waterborne polyurethane (WPU) film with silver nanoparticles (AgNPs), and demonstrated excellent sensitivity with 4-Mercaptopyridine (4-Mpy) as the probe molecule. Meanwhile, the enhancement factor of the novel SERS substrate could reach 7.01 × 106, which was consistent with the finite difference time domain (FDTD) theoretical simulation results. What's more, the high viscosity and flexibility of WPU@AgNPs sticky tapes allowed them to detect the thiabendazole residues on the pear, apple and banana surfaces by a straightforward "paste and peel off" approach. The results showed that the detection limit could reach 1.44, 1.12 and 1.63 ng/cm2. This strategy would be as a common method for prompt, on-site and ultra-sensitive assay of thiabendazole residues in chemical and biological fields.

A multi-modal probe for trace water and simultaneously monitoring lipid droplets and lysosomes.

Recently, multifunctional fluorescent probes have received more and more attention with the rapid development of fluorescence imaging technology. In this article, a multifunctional fluorescent probe NAP-OH was designed and synthesized. NAP-OH exhibited outstanding polarity-sensing performance and was used to detect trace water in different organic solvents by means of fluorescence emission intensity. The fluorescence spectroscopy results indicated that NAP-OH was highly responsive to trace water in acetone (LOD = 28 ppm). The co-localization experiment and cell starvation imaging showed that the probe NAP-OH could be used to distinguish lysosomes from lipid droplets, showing bright red fluorescence in lipid droplets and weak red fluorescence in lysosomes. The oleic acid stimulation experiment shows that the probe can detect the dynamic changes of lipid droplets while observing lysosomes. In addition, NAP-OH showed great photostability and low cytotoxicity and was successfully used in zebrafish imaging. Therefore, these results indicated that NAP-OH, as a multifunctional fluorescent probe, would be used in trace water detection and biological imaging.

Preparation of oxime compound lipid droplet-specifically labeled fluorescent probe and its application in cell imaging.

Fluorescent probes can facilitate our further comprehension of the functional and physiological roles of LDs and thus promote the development of effective therapeutic approaches. Oxime compounds are widely used due to their good crystallinity and high reactivity. However, the majority oximes fluorescent probes are usually employed for the detection of HCIO, and the application of oximes in fluorescently labeled LDS is poorly reported. In this paper, three kinds of LDs fluorescent probes (NAP-a, NAP-b and NAP-c) with D-π-A structure were synthesized by simple synthesis method with 1,8-naphthalimide as fluorescent matrix and oxime group as electron donor. These probes were highly sensitive to polarity, and possessed good photostability and low cytotoxicity. Co-staining experiments showed that these probes could target LDs and the fluorescence image was green. These probes NAP-a, NAP-b and NAP-c possessed high Pearson coefficient (HeLa cells: 0.91, 0.95, 0.86) and Manders coefficient (HeLa cells: 0.91, 0.96, 0.86) with Nile Red. Interestingly, the dynamic variations in their size, shape and distribution could be clearly observed in the oleic acid-treated cell model of LDs. Imaging of zebrafish was performed and green fluorescence was collected in zebrafish. These excellent properties make oxime compound fluorescent probes a promising fluorescent probes for studying LDs and metabolic diseases. This study opens up a new way for the preparation of LDs fluorescent probe.

A novel and fast-responsive two-photon fluorescent probe with modified group for monitoring endogenous HClO accompanied by a large turn-on signal and its application in zebrafish imaging.

Hypochlorous acid (HClO) plays a critical role in physiological activities of maintaining the stable oxidation balance of organisms, which was proved to relate to some serious diseases. In this work, 4-nitrobenzenesulfonylhydrazide based fast-responsive two-photon fluorescent probe CoPh-ClO was designed and synthesized reasonably, which possessed low cytotoxicity, good anti-interference characteristics, a large Stokes shift (85 nm), and good two-photon performance. In addition, probe CoPh-ClO was successfully applied to detect exogenous HClO in living HeLa cells and endogenous HClO in living RAW264.7 cells respectively. Moreover, we successfully achieved tissues imaging with a deep penetration depth of 65 µm and zebrafish imaging accompanied with a high contrast (about 45-fold). Interestingly, the introduce of benzene ring between fluorophore and reaction site made probe CoPh-ClO more sensitive (only 20 s) with a large turn-on signal. The probe CoPh-ClO was modified and possessed better stability (more than 10 mins) even in excessive HClO. All of mentioned above merits demonstrated that CoPh-ClO could be a promising imaging tool for monitoring HClO in various physiological processes, and the introduction of benzene ring would provide a new perspective for the development of multi-function probes.

A novel and stable fluorescent probe for tracking Hg2+ with large Stokes shift and its application in cell imaging.

Giving the fact that mercury ions (Hg2+) is highly toxic, migratory and bioaccumulative and even very small amounts of mercury can cause serious damage to health, resulting in many diseases, such as abdominal pain, renal failure, nervous system damage. The content of mercury in drinking water quality standard of our country has been strictly limited. Therefore, it is of good research interest to develop a stable fluorescent probe capable of detecting the presence of mercury in biological cells. In this study, a novel fluorescent probe based on isophoronitriles scaffold, DNC-Hg, was designed and synthesized for monitoring mercury ion in living HeLa cells. The good properties of the probe may be attributed to the unique strong electron-absorbing group in the structural design, the good conjugation effect, and the mature Hg2+ recognition site. The probe exhibited good selectivity and stability, large Stokes shift(174 nm) and low cytotoxicity. Furthermore, this stable probe DNC-Hg could be used for cellular imaging.

A lysosomal targeted fluorescent probe based on coumarin for monitoring hydrazine in living cells with high performance.

A lysosomal targeted fluorescent probe based on coumarin for monitoring hydrazine (N2H4) in living cells was designed and synthesised. The novel fluorescent probe Cou-Lyso-N2H4, in response to N2H4, exhibited good selectivity, low cytotoxicity, and lysosomal localization, which could be suitable for studying the harmfulness of N2H4 in subcellular organelles during various physiological processes.

Retraction of "Thermoresponsive Gigaporous Microspheres Facilitate the Efficient Refolding of Recombinant Nitrilase Inclusion Bodies".

[This retracts the article DOI: 10.1021/acsomega.0c00432.].

One-Pot Fabrication of Hierarchically Bicontinuous Polystyrene Monoliths with Homogeneous Skeletons and Glycopolymer Surfaces.

The hierarchically bicontinuous polystyrene monoliths (HBPMs) with homogeneous skeletons and glycopolymer surfaces are fabricated for the first time based on the medium internal phase emulsion (MIPE) templating method via activator generated by electron transfer for atom transfer radical polymerization (AGET ATRP). The synergistic self-assembly of amphiphilic diblock glycopolymer (ADG) and Pluronic F127 (PF127) at the oil/water interface via hydrogen bonding interaction contributes to the formation of bicontinuous MIPE with deformed neighboring water droplets, resulting in the highly interconnected HBPM after polymerization. There is a bimodal pore size distribution in the HBPM, that is, through pores (150-5000 nm) and mesopores (10-150 nm). The HBPMs as prepared show excellent biocompatibility, homogeneous skeletons, strong mechanical strength, and high bed permeability, overcoming the practical limitations of the second generation of polystyrene (PS) monoliths. Glycoprotein concanavalin A (Con A) can be easily and quickly separated by the HBPM in hydrophilic interaction chromatography (HILIC) mode. These results suggest the HBPMs have great potentials in catalysis, separations, and biomedical applications.

Construction of flexible, transparent and mechanically robust SERS-active substrate with an efficient spin coating method for rapidin-situtarget molecules detection.

Flexible, transparent and mechanically robust surface enhanced Raman scattering (SERS)-active substrates is currently the most attractive research focus in the field of Raman detection, and also a powerful analysis and identification technique in the biological research. Herein, we introduced a low-cost and large-scale method to fabricate flexible and transparent AgNPs/WPU plasmonic metafilm with monolayer-island phase nanostructures based on silver nanoparticles (AgNPs) and waterborne polyurethane emulsion (WPU) film. The obtained AgNPs/WPU plasmonic metafilm demonstrated excellent SERS sensitivity, signal uniformity and reproducibility, and the SERS substrates could still maintain excellent stability even after being bent or stretched over 100 cycles. The detection concentration was as low as 10-9M with 4-Mercaptobenzoic acid (4-MBA) as probe molecule, and the enhancement factor was high to 2.2 × 107. More importantly, the flexibility and adhesivity of AgNPs/WPU plasmonic metafilm could be directly conformal coverage on the apple surface forin situdetection of thiram residue, and the detection limit was as low as 9.0165 ng cm-2. This versatile AgNPs/WPU plasmonic metalfilm would be a promising SERS substrate for the detection of pesticide residue in chemical and biological applications.

Recyclable Shape-Memory Waterborne Polyurethane Films Based on Perylene Bisimide Modified Polycaprolactone Diol.

Currently, much attention is given to the functionality and recyclability of waterborne polyurethane (WPU). Herein, ε-caprolactone was used as a chain extender for grafting onto perylene bisimide (PBI) and 1,4-butanediol (BDO) via ring-opening reactions to obtain PBI-PCL and BDO- PCL. Then, two kinds of WPU, namely PBI-WPU (PWPU) and BDO-WPU (BWPU), were fabricated using PBI-PCL/polytetrahydrofuran ether glycol (PTMG) and BDO-PCL/PTMG, respectively, as mixed soft segments. The properties and appearance of PWPU and BWPU emulsions were analyzed in terms of particle size, zeta potential and TEM images, and the results showed that PWPU emulsions had uniform particle size distribution and decent storage stability. AFM and DMA results revealed that PWPU films possessed a more significant degree of microphase separation and a higher glass transition temperature (Tg) than BWPU films. The PWPU films displayed good shape-memory and mechanical properties, with tensile strength up to 58.25 MPa and elongation at break up to 1241.36%. TGA analysis indicated that PWPU films had better thermal stability than BWPU films. More importantly, the PWPU films could be dissolved in a mixed solvent of acetone/ethanol (v/v = 2:1) at room temperature. The dissolved PWPU could be dispersed in deionized water to prepare waterborne polyurethane again. After the recycling process was repeated three times, the recycled PWPU emulsion still exhibited good storage stability. The recycled PWPU films maintained their original thermal and mechanical properties. Comparing the properties of BWPU and PWPU showed that the soft segment structure had important influence on waterborne polyurethane performance. Therefore, PWPU may have great potential applications in making recycling and shape-memory coating or paint.

A sensitive bio-probe for tracking lipid droplets with large Stokes shift and its application in cell imaging.

Lipid droplets (LDs) including triacylglycerols and cholesteryl esters are applied for protein transformation and protein maturation in living bodies, which have an important effect on lipid metabolism, homeostasis, and interactions with other organelles. The imbalance of LDs could lead to many serious diseases including insulin resistance, cancer, obesity, liver disease, cardiovascular disease, and neurodegenerative disease. The diameter distribution of LDs is quite extensive from 100 nm to 100 µm. Herein, we designed and constructed a novel organic bio-probe TzAr-N for LDs cell imaging with much more hydrophobic and viscous environment compared to cytosol by using 1,3,5-triazine as electron acceptor. This sensitive probe exhibited favorable merits including large Stokes shift (almost 80 nm), good LDs targeting ability, and a low biological toxicity, which also could not be affected by wide range of pH values. Furthermore, the bio-probe TzAr-N could also mark LDs distribution in living HeLa cells.

[Formulation of technical guidelines in line with characteristics and principles of traditional Chinese medicine changes to improve quality of such preparations--interpretation of Technical guidelines for the study of pharmaceutical changes in traditional Chinese medicines].

In leading the high-quality development of Chinese medicine preparations, it is an important link to formulate the scientific, reasonable, and feasible guidelines for the change of Chinese medicines in accordance with the change characteristics and principles of the Chinese medicines is an important work to promote the Technical guidelines for the study of pharmaceutical changes in traditional Chinese medicines was formed by a broad consensus based on the characteristics and research results of the pharmaceutical changes in Traditional Chinese Medicines(TCM)with the principles of science and risk management. This guideline has clarified the basic principles and requirements for the evaluation of changes in TCM, specified the research and verification work of common change scenarios, defined the boundaries of changes in TCM, and proposed to encourage the use of new technologies, new methods, and new excipients that meet product characteristics. It will definitely promote the quality improvement and the secondary development of TCM. In this article, the revision background and main content of the guideline were introduced, and the main features of the Guideline were analyzed, in order to provide references for the industry.

Cloning and characterization of a novel thermostable amidase, Xam, from Xinfangfangia sp. DLY26.

OBJECTIVE: Identification and characterization of a novel thermostable amidase (Xam) with wide pH tolerance and broad-spectrum substrate specificity. RESULTS: Xam was identified from non-thermophilic Xinfangfangia sp. DLY26 and its acyl transfer activity was investigated. Recombinant Xam was optimally active at 60 °C and pH 9.0. The enzyme had a half life of 18 h at 55 °C and maintained more than 60 % of its maximum activity in the range of pH 3.0-11.0. Additionally, Xam exhibited broad substrate specificity towards aliphatic, aromatic, and heterocyclic amides. CONCLUSIONS: These unique properties make Xam a promising biocatalyst for production of important hydroxamic acids at elevated temperatures.

In-situ grafting temperature-responsive hydrogel as a bifunctional solid-phase microextraction coating for tunable extraction of biomacromolecules.

A temperature-responsive solid-phase microextraction (SPME) coating was prepared via in-situ atom transfer radical polymerization (ATRP) method. By controlling the temperature of solution below and above the lower critical solution temperature (LCST) of the coating, it can switch between hydrophilic and hydrophobic, thus providing a convenient approach for the selective extraction of analytes with different polarities. The average extraction amount of temperature-responsive coating for polar analytes is about 1.5-fold to that of non-polar ones below LCST, and vice versa. Effective extraction of three biomacromolecules was also obtained by controlling the temperature below or above LCST. The adsorption capacity of the coating for the hydrophilic biomacromolecules at 15 °C is 1.5-2 folds that of 50 °C, whereas the adsorption capacity of the coating to BSA at 50 °C is about 3 folds that of 15 °C. This approach holds great promise for SPME because it provides a simple strategy to prepare bifunctional coatings for various applications.