Design, synthesis and biological evaluation of novel modified dual-target shikonin derivatives for colorectal cancer treatment.

Warburg effect provides energy and material essential for tumor proliferation, the reverse of Warburg effect provides insights into the development of a novel anti-cancer strategy. Pyruvate kinase 2 (PKM2) and pyruvate dehydrogenase kinase 1 (PDK1) are two key enzymes in tumor glucose metabolism pathway that not only contribute to the Warburg effect through accelerating aerobic glycolysis, but also serve as druggable target for colorectal cancer (CRC). Considering that targeting PKM2 or PDK1 alone does not seem to be sufficient to remodel abnormal glucose metabolism and achieve significant antitumor activity, a series of novel benzenesulfonyl shikonin derivatives were designed to regulate PKM2 and PDK1 simultaneously. By means of molecular docking and antiproliferative screen, we found that compound Z10 could act as the combination of PKM2 activator and PDK1 inhibitor, thereby significantly inhibited glycolysis that reshaping tumor metabolism. Moreover, Z10 could inhibit proliferation, migration and induce apoptosis in CRC cell HCT-8. Finally, the in vivo anti-tumor activity of Z10 was evaluated in a colorectal cancer cell xenograft model in nude mice and the results demonstrated that Z10 induced tumor cell apoptosis and inhibited tumor cell proliferation with lower toxicity than shikonin. Our findings indicated that it is feasible to alter tumor energy metabolism through multi-target synergies, and the dual-target benzenesulfonyl shikonin derivative Z10 could be a potential anti-CRC agent.

Composite acousto-optical modulation.

We propose a composite acousto-optical modulation (AOM) scheme for wide-band, efficient modulation of CW and pulsed lasers. We show that by adjusting the amplitudes and phases of weakly-driven daughter AOMs, diffraction beyond the Bragg condition can be achieved with exceptional efficiencies. Furthermore, by imaging pairs of AOMs with opposite directions of sound-wave propagation, high contrast switching of output orders can be achieved at the driving radio frequency (rf) limit, thereby enabling efficient bidirectional routing of a synchronized mode-locked laser. Here we demonstrate a simplest example of such scheme with a double-AOM setup for efficient diffraction across an octave of rf bandwidth, and for routing a mode-locked pulse train with up to frep = 400 MHz repetition rate. We discuss extension of the composite scheme toward multi-path routing and time-domain multiplexing, so as to individually shape each pulses of ultrafast lasers for novel quantum control applications.

Anti-microbial efficacy, mechanisms and druggability evaluation of the natural flavonoids.

AIMS: This study was conducted to evaluate 35 natural flavonoids for their in vitro susceptibility against E. coli (ATCC 25922), Ps. aeruginosa (ATCC 27853), B. subtilis (ATCC 530) and Staph. aureus (ATCC 6538) in search of a potential broad-spectrum antibiotic. METHODS AND RESULTS: Glabridin, a natural isoflavonoid isolated from Glycyrrhiza glabra L., was identified to be highly active with a MIC of 8-16 µg ml-1 against Staph. aureus, B. subtilis and E. coli. By the results of the docking simulation, we located the potential targets of glabridin as DNA gyrase and dihydrofolate reductase (DHFR). The subsequent DNA gyrase inhibition assays (glabridin: IC50  = 0.8516 µmol L-1 , ciprofloxacin: IC50  = 0.04697 µmol L-1 ), DHFR inhibition assays (glabridin: inhibition ratio = 29%, methotrexate: inhibition ratio = 45% under 100 µmol L-1 treatment) and TUNEL confirmed that glabridin acted as DNA gyrase inhibitor and DHFR mild inhibitor, exerting bactericidal activity by blocking bacterial nucleic acid synthesis. CCK-8 and in silico calculations were also conducted to verify the low cytotoxicity and acceptable druggability of glabridin. CONCLUSION: These findings suggest that glabridin represents the prototypical member of an exciting structural class of natural antimicrobial agents. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reports a novel mechanism of bactericidal activity of glabridin against Staph. aureus.

Precise pulse shaping for quantum control of strong optical transitions.

Advances of quantum control technology have led to nearly perfect single-qubit control of nuclear spins and atomic hyperfine ground states. In contrast, quantum control of strong optical transitions, even for free atoms, are far from being perfect. Developments of such quantum control appears to be limited by available laser technology for generating isolated, sub-nanosecond optical waveforms with 10's of GHz programming bandwidth. Here we propose a simple and robust method for the desired pulse shaping, based on precisely stacking multiple delayed picosecond pulses. Our proof-of-principal demonstration leads to arbitrarily shapeable optical waveforms with 30 GHz bandwidth and 100 ps duration. We confirm the stability of the waveforms by interfacing the pulses with laser-cooled atoms, resulting in "super-resolved" spectroscopic signals. This pulse shaping method may open exciting perspectives in quantum optics, and for fast laser cooling and atom interferometry with mode-locked lasers.

Geometric Control of Collective Spontaneous Emission.

Dipole spin-wave states of atomic ensembles with wave vector k(ω) mismatched from the dispersion relation of light are difficult to access by far-field excitation but may support rich phenomena beyond the traditional phase-matched scenario in quantum optics. We propose and demonstrate an optical technique to efficiently access these states. In particular, subnanosecond laser pulses shaped by a home-developed wideband modulation method are applied to shift the spin wave in k space with state-dependent geometric phase patterning, in an error-resilient fashion and on timescales much faster than spontaneous emission. We verify this control through the redirection, switch off, and recall of collectively enhanced emission from a ^{87}Rb gas with ∼75% single-step efficiency. Our work represents a first step toward efficient control of electric dipole spin waves for studying many-body dissipative dynamics of excited gases, as well as for numerous quantum optical applications.

Silica-Lipid Hybrid Microparticles as Efficient Vehicles for Enhanced Stability and Bioaccessibility of Curcumin.

Curcumin is an active ingredient with multiple functions, but its application is often restricted due to its poor water solubility, weak stability, and consequently low bioaccessibility. Based on this, the aim of this work is to develop a new vehicle to overcome these restrictions. Here we developed a curcumin-loaded nanoemulsion and then curcumin-loaded silica-lipid hybrid microparticles through emulsification and vacuum drying, respectively. The loading of curcumin in the nanoemulsion and microparticles was (0.30±0.02) and (0.67±0.02) %, respectively. FTIR and XRD analyses of microparticles revealed that curcumin was encapsulated in porous, amorphous silica. In vitro antioxidant activities showed that the encapsulation would not affect the antioxidant activity of curcumin. In vitro simulated digestion indicated that nanoemulsion and microparticles had higher curcumin bioaccessibility than the control group. The storage stability of microparticles remained the same during 6 weeks in the dark at 4, 25 and 40 °C. Moreover, the microparticles had a better chemical stability than nanoemulsion under the light. The cell viability was over 80% when the concentration of nanocarriers was less than 45 µg/mL. Hence, the microparticles could be a promising means to load curcumin and improve its solubility, light stability and bioaccessibility.

PKM2/PDK1 dual-targeted shikonin derivatives restore the sensitivity of EGFR-mutated NSCLC cells to gefitinib by remodeling glucose metabolism.

Pyruvate kinase 2 (PKM2) and pyruvate dehydrogenase kinase 1 (PDK1) are two key enzymes in tumor glucose metabolism pathway that not only promote tumor growth and proliferation through accelerating aerobic glycolysis, but also contribute to drug resistance of non-small cell lung cancer (NSCLC). Considering that targeting PKM2 or PDK1 alone seems insufficient to remodel abnormal glucose metabolism to achieve significant antitumor activity, we proposed a "two-step approach" that regulates PKM2 and PDK1 synchronously. Firstly, we found that the combination of ML265 (PKM2 activator) and AZD7545 (PDK1 inhibitor) could synergistically inhibit proliferation and induce apoptosis in H1299 cells. Base on this, we designed a series of novel shikonin (SK) thioether derivatives as PKM2/PDK1 dual-target agents, among which the most potent compound E5 featuring a 2-methyl substitution on the benzene ring exerted significantly increased inhibitory activity toward EGFR mutant NSCLC cell H1975 (IC50 = 1.51 µmol/L), which was 3 and 17-fold more active than the lead compound SK (IC50 = 4.56 µmol/L) and the positive control gefitinib (IC50 = 25.56 µmol/L), respectively. Additionally, E5 also showed good anti-tumor activity in xenografted mouse models, with significantly lower toxicity side effects than SK. Moreover, E5 also inhibited the entry of PKM2 into nucleus to regulate the transcriptional activation of oncogenes, thus restoring the sensitivity of H1975 cell to gefitinib. Collectively, these data demonstrate that E5, a dual inhibitor of PKM2/PDK1, may be a promising adjunct to gefitinib in the treatment of EGFR-TKIs resistant NSCLC, deserving further investigation.

The host niches of soybean rather than genetic modification or glyphosate application drive the assembly of root-associated microbial communities.

Plant roots significantly influence soil microbial diversity, and soil microorganisms play significant roles in both natural and agricultural ecosystems. Although the genetically modified (GM) crops with enhanced insect and herbicide resistance are thought to have unmatched yield and stress resistance advantages, thorough and in-depth case studies still need to be carried out in a real-world setting due to the potential effects of GM plants on soil microbial communities. In this study, three treatments were used: a recipient soybean variety Jack, a triple transgenic soybean line JD321, and the glyphosate-treated JD321 (JD321G). Three sampling stages (flowering, seed filling and maturing), as well as three host niches of soybean rhizosphere [intact roots (RT), rhizospheric soil (RS) and surrounding soil (SS)] were established. In comparison to Jack, the rhizospheric soil of JD321G had higher urease activity and lower nitrite reductase at the flowering stage. Different treatments and different sampling stages existed no significant effects on the compositions of microbial communities at different taxonomic levels. However, at the genus level, the relative abundance of three plant growth-promoting fungal genera (i.e. Mortierella, Chaetomium and Pseudombrophila) increased while endophytic bacteria Chryseobacterium and pathogenic bacteria Streptomyces decreased from the inside to the outside of the roots (i.e. RT → RS → SS). Moreover, two bacterial genera, Bradyrhizobium and Ensifer were more abundant in RT than in RS and SS, as well as three species, Agrobacterium radiobacter, Ensifer fredii and Ensifer meliloti, which are closely related to nitrogen-fixation. Furthermore, five clusters of orthologous groups (COGs) associated to nitrogen-fixation genes were higher in RT than in RS, whereas only one COG annotated as dinitrogenase iron-molybdenum cofactor biosynthesis protein was lower. Overall, the results imply that the rhizosphere host niches throughout the soil-plant continuum largely control the composition and function of the root-associated microbiome of triple transgenic soybean.

Novel shikonin derivatives suppress cell proliferation, migration and induce apoptosis in human triple-negative breast cancer cells via regulating PDK1/PDHC axis.

AIMS: PDK1 is one of the key enzymes in the glucose metabolism pathway, which is abnormally high expressed in breast cancer tissues and can promote tumor proliferation and metastasis. PDK1 and the PDHC/PDK axis are important targets for regulating glucose metabolism and anti-tumor activity. In this study, we evaluated the anti-tumor activities of a series of semi-synthesized shikonin (SK) derivatives against human breast cancer cells. MAIN METHODS: The anti-proliferation activity of SK derivatives against human breast cancer cell lines was tested by CCK-8 and EdU assay. Flow cytometry was utilized to evaluate cell apoptosis, reactive oxygen species and cell cycle distribution. Cell migration ability was determined by wound healing and trans-well assay. PDK1 targeting effect was confirmed by western bolting, molecular docking, bio-layer interferometry and PDK1 enzyme activity assay. Nude-mouse transplanted tumor model was used to evaluate their anti-tumor effect in vivo. KEY FINDINGS: Findings revealed that SK derivatives had good anti-proliferation ability against MDA-MB-231 cell. They induced cell apoptosis by regulating the mitochondrial apoptosis and death receptor pathway. They also inhibited cell migration by suppressing EMT progression. Molecular docking, PDK1 affinity and enzyme activity demonstrated their PDK1 targeting. In vivo antitumor experiment showed that E2 could significantly inhibit tumor growth with lower side-effect on mice than SK. SIGNIFICANCE: In conclusion, the novel SK derivatives E2 and E5 inhibited tumor glycolysis by targeting PDK1 and ultimately induced apoptosis. Our data demonstrated that E2 would be a good lead compound for the treatment of human TNBC as a novel PDK1 inhibitor.

Topical delivery of chemotherapeutic drugs using nano-hybrid hydrogels to inhibit post-surgical tumour recurrence.

Residual microtumours after surgical resection leading to tumour relapse is one of the major challenges for cancer therapy. Herein, we developed a nano-hybrid oligopeptide hydrogel for topical delivery of a chemotherapeutic drug, docetaxel (DTX), to inhibit the post-surgical tumour recurrence. This nano-hybrid hydrogel (DTX-CTs/Gel) was prepared by encapsulating DTX in cell-penetrating peptide-modified transfersomes followed by embedment in an oligopeptide hydrogel. The obtained DTX-CTs/Gel showed paintable and injectable properties, and could support prolonged retention at the administrated sites after topical administration. DTX-CTs released from the hydrogel presented high skin and tumour penetration capabilities, and increased the accumulation of DTX in the cancer cells leading to enhanced cell death. We showed that the topical delivery of DTX using DTX-CTs/Gel efficiently slowed down the tumour relapse in post-surgical mouse melanoma and breast tumour models.

Enzyme-instructed hybrid nanogel/nanofiber oligopeptide hydrogel for localized protein delivery.

Enzyme-catalysis self-assembled oligopeptide hydrogel holds great interest in drug delivery, which has merits of biocompatibility, biodegradability and mild gelation conditions. However, its application for protein delivery is greatly limited by inevitable degradation of enzyme on the encapsulated proteins leading to loss of protein activity. Moreover, for the intracellularly acted proteins, cell membrane as a primary barrier hinders the transmembrane delivery of proteins. The internalized proteins also suffer from acidic and enzymatic degradation in endosomes and lysosomes. We herein develop a protease-manipulated hybrid nanogel/nanofiber hydrogel for localized delivery of intracellularly acted proteins. The embedded polymeric nanogels (CytoC/aNGs) preserve activity of cytochrome c (CytoC) that is an intracellular activator for cell apoptosis as a model protein against proteolysis, and do not affect the gelation properties of the protease-catalysis assembled hydrogels. The injectable hydrogel (CytoC/aNGs/Gel) serves as a reservoir to enhance intratumoral retention and realize sustainable release of CytoC/aNGs. The released CytoC/aNGs increase cellular uptake of CytoC and enhance its intracellular delivery to its target site, cytoplasm, resulting in favorable apoptosis-inducing and cytotoxic effects. We show that a single local administration of CytoC/aNGs/Gel efficiently inhibit the tumor growth in the breast tumor mouse model.

Oriented efficient biosynthesis of rare ginsenoside Rh2 from PPD by compiling UGT-Yjic mutant with sucrose synthase.

Ginsenoside Rh2 (3ß-O-Glc-protopanaxadiol), a trace but an important pharmacological component of ginseng, has exhibited excellent medicinal potential. Many studies have found that the synthesis of Rh2 by UDP-glucosyltransferase (UGT) is an alternative production strategy. In this study, Yjic from B. subtilis 168 was found to synthesize ginsenoside F12 (3ß,12ß-Di-O-Glc-protopanaxadiol) and Rh2 at a ratio of 7:3. Yjic regioselectivity toward Rh2 synthesis was successfully improved using a semi-rational design including structure-guided alanine scanning and saturation mutations. As a result, mutant M315F was found to efficiently synthesize Rh2 (~99%) and block the further glycosylation of C12-OH. The circulation of UDPG was achieved by combining M315F with AtSuSy through a cascade reaction. Furthermore, an extraordinarily high yield of Rh2 (3.7 g/L) was attained in an aqueous solvent system with 17% DMSO (v/v) through the fed-batch feeding of PPD. This study presents the high potential for the oriented preparation of ginsenoside Rh2.

Study of the modification mechanism of heavy metal ions adsorbed by biomass-activated carbon doped with a solid nitrogen source.

In this study, the N-doping of biomass-activated carbon with dicyandiamide was performed via an ultrasonic method and a redox method. BET, SEM, EDS, FT-IR and XPS were used to determine the pore structures, morphologies and surface chemistry of the adsorbents obtained. The N-doping effect of the two modification methods on the same solid nitrogen source was evaluated and the simulated adsorption experiments of heavy metal ions in wastewater were conducted. The results showed that the N-doped biomass-activated carbon having the higher doping content was obtained by a redox method with nitric acid at 25 °C, a solid nitrogen source ratio of 1 : 1 and charring at 800 °C for 2 hours. The adsorption efficiency for the divalent copper ion of the sample obtained by the redox method was 41.15% higher than that of the ultrasonic method sample, and proved that pyridinium nitrogens and amino groups play important roles in adsorption and complexation processes. The isothermal adsorption experiments of N-doped activated carbon conformed to the Freundlich model, which mainly depended on chemical adsorption. The kinetics for copper ion adsorption followed a pseudo-second-order kinetic model. Thermodynamic experiments showed that a higher temperature was advantageous to adsorption. Simultaneously, this study further analyzed the N-doping process of the redox method sample and suggested that improvements can be implemented in the N-doping of activated carbon with solid nitrogen sources.

Solid Self-Emulsifying Delivery System (S-SEDS) of Dihydromyricetin: A New Way for Preparing Functional Food.

The present study was aimed at formulating and evaluating a novel solid self-emulsifying delivery system (S-SEDS) for the application in functional foods of dihydromyricetin (DMY). First, solubility study and pseudo-ternary phase diagram analysis were adopted to optimize the formulation of liquid self-emulsifying delivery system (L-SEDS). And the thermodynamic stable L-SEDS with 5% content of DMY was fabricated and further developed into a solid form via vacuum rotary evaporation with Aerosil 300 as the solid adsorbent. Solid state characterization of the S-SEDS was performed by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray powder diffraction. Furthermore, studies proved that the antioxidant activity and bioaccessibility of DMY were improved after incorporated into S-SEDS formulation compared to pure DMY. The S-SEDS showed good resistance against various storage conditions investigated for 10 weeks. PRACTICAL APPLICATION: Solid self-emulsifying delivery system (S-SEDS) combined the advantages of liquid self-emulsifying delivery system with those of a solid dosage form to overcome the disadvantages associated with liquid formulations is more convenient for storage and transportation in practical application. Furthermore, the technology of producing S-SEDS is simple and can be realized in industrial production. Hence, S-SEDS could be a promising strategy to overcome the poor water solubility and short biological half-life of dihydromyricetin for further application in functional foods and beverage industry.

Enhanced Transdermal Drug Delivery by Transfersome-Embedded Oligopeptide Hydrogel for Topical Chemotherapy of Melanoma.

Topical administration of anticancer drugs provides a potential chemotherapeutic modality with high patient compliance for cutaneous melanoma. However, the drug delivery efficiency is highly limited by physiological barriers from the skin to the tumor, which cannot acquire desired therapeutic efficacy. Herein, we propose a paintable oligopeptide hydrogel containing paclitaxel (PTX)-encapsulated cell-penetrating-peptide (CPP)-modified transfersomes (PTX-CTs) to enhance transdermal PTX delivery for topical melanoma treatment. After being plastered on the skin above the melanoma tumor, the PTX-CTs-embedded hydrogel (PTX-CTs/Gel) as a patch provided prolonged retention capacity of the PTX-CTs on the skin. The PTX-CTs with superior deformability could efficiently squeeze through the channels in the stratum coreum, and the surfactant components improved the fluidity of the lipid molecules in the stratum corneum to further enhance the skin permeation. Moreover, the CPP modification rendered the PTX-CT-enhanced penetration in the skin and tumor stroma as well as efficient transportation in the tumor cells. The PTX-CTs were shown to effectively slow the tumor growth in combination with the systemic chemotherapy using Taxol, the commercial PTX formulation on the xenograft B10F16 melanoma mouse model.