Global Lysine Acetylation and 2-Hydroxyisobutyrylation Profiling Reveals the Metabolism Conversion Mechanism in Giardia lamblia.

Giardia lamblia (G. lamblia) is the cause of giardiasis, a common infection that affects the general population of the world. Despite the constant possibility of damage because of their own metabolism, G. lamblia has survived and evolved to adapt to various environments. However, research on energy-metabolism conversion in G. lamblia is limited. This study aimed to reveal the dynamic metabolism conversion mechanism in G. lamblia under sugar starvation by detecting global lysine acetylation (Kac) and 2-hydroxyisobutyrylation (Khib) sites combined with quantitative proteome analyses. A total of 2999 acetylation sites on 956 proteins and 8877 2-hydroxyisobutyryl sites on 1546 proteins were quantified under sugar starvation. Integrated Kac and Khib data revealed that modified proteins were associated with arginine biosynthesis, glycolysis/gluconeogenesis, and alanine, aspartate, and glutamate metabolisms. These findings suggest that Kac and Khib were ubiquitous and provide deep insight into the metabolism conversion mechanism in G. lamblia under sugar starvation. Overall, these results can help delineate the biology of G. lamblia infections and reveal the evolutionary rule from prokaryote to eukaryote.

A redox-responsive dihydroartemisinin dimeric nanoprodrug for enhanced antitumor activity.

Redox-responsive drug delivery system emerges as a hopeful platform for tumor treatment. Dihydroartemisinin (DHA) has been investigated as an innovative tumor therapeutic agent. Herein, a DHA dimeric prodrug bridged with disulfide bond as linker (DHA2-SS) has been designed and synthesized. The prepared prodrugs could self-assemble into nanoparticles (SS NPs) with high DHA content (> 90%) and robust stability. These SS NPs display sensitive redox responsive capability and can release DHA under the tumor heterogeneity microenvironment. SS NPs possess preferable antitumor therapeutic activity in contrast with free DHA. Moreover, the possible anti-cancer mechanism of SS NPs was investigated through RNA-seq analysis, bioinformatics and molecular biological method. SS NPs could induce apoptosis via mitochondrial apoptosis pathway, as well as glycolysis inhibition associate with the regulation of PI3K/AKT/HIF-1α signal path, which may offer an underlying therapeutic target for liver cancer. Our study highlights the potential of using redox responsive prodrug nanoparticles to treat cancer, meanwhile provides insights into the anti-cancer mechanism of DHA prodrug.

Targeted juglone blocks the invasion and metastasis of HPV-positive cervical cancer cells.

Human papillomaviruses (HPVs), for instance, HPV 16 and HPV 18, are concerned associated with cervical cancer. Thus, it is essential to suppress HPVs-in HPV-positive cervical cancer for treating cervical cancer. The purpose of this study was to explore the proposed molecular mechanisms, which that underlies the antintumor potential of juglone to treat of HPV-positive on cervical cancer cells. The results showed that juglone suppressed HPV-positive cell growth in a dose- and time-dependent way. In addition, cell invasion and metastasis were also inhibited by juglone. Nevertheless, when pin 1 was knocked down in HPV-positive cells, cell proliferation, invasion and metastasis were reduced. This study was designed to acquire an understanding of the mechanism of invasion and metastasis in HPV-positive cells suppressed by juglone. It provides evidence of the advantageous use of juglone in the future.

Juglone Inhibits Proliferation of HPV-Positive Cervical Cancer Cells Specifically.

Human papillomaviruses (HPVs), such as HPV 16 and HPV 18 are related to cervical cancer. Therefore, it is important to inhibit HPV-positive cervical cancer for treating cervical cancer. This study is aiming at investigating the proposed molecular mechanism, which underlies the antineoplastic potential of the aqueous extract of juglone of HPV-positive cervical cancer cells. According to the results, it is showed that, juglone prohibited HPV positive cervical cancer cells' growth through dose-dependent way. Nevertheless, when pin 1 was knocked down, the proliferation inhibition reduced. The detection of apoptosis and cell cycle also illustrated that juglone influenced HPV positive cells. Western blot expressed the influence mechanism that it affected the B-cell lymphoma 2 (Bcl-2) family and later activated the Caspase-depended apoptosis way. It is contributable for this study to understand the mechanism of inhibiting HPV positive cells by juglone and it also provides an effective strategy for the application of it in the future.

Protective effects and plausible mechanisms of antler-velvet polypeptide against hydrogen peroxide induced injury in human umbilical vein endothelial cells.

Antler velvet polypeptide (VAP) is a prominent bioactive component of antler velvet. Whereas uncharacterized crude extracts have typically been used in pharmacological studies, in this study, the velvet polypeptide was isolated and purified by acid water extraction, ethanol precipitation, ammonium sulfate fractionation and precipitation, and chromatography, progressively. Human umbilical vein endothelial cells (HUVECs) were induced with H2O2 followed purified polypeptide treatment. Cell viability was evaluated by MTT assay. The apoptosis of cells was detected by fluorescence microscopy and flow cytometry. A cell analyzer was used to measure the mitochondrial membrane potential. The intracellular reactive oxygen species (ROS) levels were determined by flow cytometry. Oxidative stress related biochemical parameters were detected, and the expression of apoptosis-related proteins was examined by Western blot analysis. The results indicated that a 7.0 kDa polypeptide (VAP II) was isolated from antler velvet. VAP II enhanced cell viability, decreased cell apoptosis, reversed depolarization of mitochondrial membrane potential, decreased ROS levels, inhibited oxidative stress, and regulated the downstream signaling apoptotic cascade expression caused by H2O2. The protective effects of VAP II on HUVECs suggests a potential strategy for the treatment of cardiovascular disease.

[Dihydroartemisinin inhibits proliferation of pancreatic cancer JF-305 cells by regulating expression of apoptosis related proteins and production of reactive oxygen species].

To investigate the effect of dihydroartemisinin on apoptosis of human pancreatic cancer cell line JF-305 and the role of reactive oxygen species(ROS) in the apoptosis of JF-305 cells induced by dihydroartemisinin. MTT assays were used to detect effect of different concentrations of dihydroartemisinin on cells proliferation of JF-305 lines. Cell cycle was detected by flow cytometry, and the apoptotic morphology was observed by Hoechst 333258 fluorescence staining. Annexin V fluorescence staining was used to detect the apoptosis changes of JF-305 cells, while DCFH-DA was used to detect the changes of ROS during apoptosis process. Western blot was used to detect the protein expression changes of Bax, Bcl-2, Cleaved caspase-3, Cleaved caspase-9 and Cyto C. As compared with the control group, the JF-305 cells proliferation was inhibited significantly(P<0.05) after treatment with different concentrations of dihydroartemisimin for 48 h; cell cycle was blocked in the G2/M phase; apoptotic morphology of nuclear condensation, aggregation, and fragmentation was found, and the apoptosis ratio was increased(P<0.05). DCFH-DA detection showed that the cell ROS was increased significantly after dihydroartemisinin treatment(P<0.05). Western blot results showed that the expression of Bcl-2 protein was down-regulated; the expression of Bax protein was up-regulated; the ration of Bax/Bcl-2 was increased and the protein expression levels of Cleaved caspase-3, Cleaved caspase-9 and Cyto C were increased after dihydroartemisinin treatment. Therefore, dihydroartemisinin could induce apoptosis of JF-305 cells, and the possible mechanism may be related to the formation and increasing of ROS.

CSL regulates AKT to mediate androgen independence in prostate cancer progression.

BACKGROUND: Aberrant signaling pathways leads to cancer initiation and progression. Both Notch and PI3K/AKT signaling pathways are believed to be involved in prostate cancer. How the interaction between the two pathways contributes to prostate cancer progression to androgen independence is still elusive. METHODS: Prostate cancer cells were grown in RPMI 1,640 supplemented with 10% heat-inactivated fetal bovine serum (FBS) or 10% charcoal-stripped heat-inactivated fetal bovine serum (FCS), 1% penicillin-streptomycin in 75 cm2 polystyrene flasks, and maintained at 37 °C in a humidified atmosphere with 5% CO2 . Cell proliferation, invasion were performed with cell counting, matrigel assay in vitro. Dual luciferase assays were performed using reporter plasmids with ARE (Androgen Response Element, ARE). RNA interference was applied to gene silence. Tumorigenicity of cancer cells was evaluated by mouse xenograft in vivo. RESULTS: A subpopulation of casodex resistant prostate cancer cells were identified with an overexpressed androgen receptor (AR) and aggressive phenotypes, characterized with high proliferation, invasion in vitro and enhanced tumorigenesis in vivo. Gene profiling for androgen-dependent LNCaP and androgen-independent LNCaP-CR revealed that both CSL and AKT gave the similar expressional pattern upon casodex treatment. Immunoblot demonstrated that CSL and AKT were dramatically suppressed in androgen dependent LNCaP cells, but slightly inhibited in LNCaP-CR cells as well as other androgen independent prostate cancer cells. Further studies indicated that CSL regulates AKT, and subsequently AR in prostate cancer cells. AKT mediates casodex resistance and androgen independence through regulation of cyclin D1. CONCLUSION: CSL-AKT-AR axis might play an important role in prostate cancer progression. Targeting CSL depleted the casodex resistant population through inhibition of the AKT, suggesting a more effective therapeutic strategy for abrogating casodex resistance in advanced prostate cancer.

The apoptotic effect and the plausible mechanism of microwave radiation on rat myocardial cells.

Microwaves may exert adverse biological effects on the cardiovascular system at the integrated system and cellular levels. However, the mechanism underlying such effects remains poorly understood. Here, we report a previously uncharacterized mechanism through which microwaves damage myocardial cells. Rats were treated with 2450 MHz microwave radiation at 50, 100, 150, or 200 mW/cm(2) for 6 min. Microwave treatment significantly enhanced the levels of various enzymes in serum. In addition, it increased the malondialdehyde content while decreasing the levels of antioxidative stress enzymes, activities of enzyme complexes I-IV, and ATP in myocardial tissues. Notably, irradiated myocardial cells exhibited structural damage and underwent apoptosis. Furthermore, Western blot analysis revealed significant changes in expression levels of proteins involved in oxidative stress regulation and apoptotic signaling pathways, indicating that microwave irradiation could induce myocardial cell apoptosis by interfering with oxidative stress and cardiac energy metabolism. Our findings provide useful insights into the mechanism of microwave-induced damage to the cardiovascular system.

[Effect of Qidan Granule on PMC Derived Peptide Content and Structure of Hippocampal CA1 Region in Microwave Radiated Rats].

OBJECTIVE: To explore the protection of high intensity microwave radiation on hypothalamo-pituitary-adrenal axis (HPAA) activity and hippocampal CA1 structure in rats and the protectiveeffect of Qindan Granule (QG) on radiation injured rats. METHODS: Totally 48 Wistar rats were randomlydivided into 8 groups, i.e., the normal control group, post-radiation day 1, 7, and 10 groups, 7 and 10days prevention groups, day 7 and 10 treatment groups, 6 in each group. Rats in prevention groups wererespectively administered with QG liquid (1 mL/100 g, 4. 75 g crude drugs) for 7 days and 10 days bygastrogavage and then microwave radiation. Then preventive effect for radiation injury was statisticallycalculated with the normal control group and the post-radiation day 1 group. Rats in treatment groupswere firstly irradiated, and then administered with QG liquid (1 mL/100 g, 4.75 g crude drugs). Finally preventive effect for radiation injury was statistically calculated with the normal control group, post-radiation day 7 and 10 groups. Contents of corticotrophin releasing hormone (CRH), beta endorphin (beta-EP), adrenocorticotropic hormone (ACTH), and heat shock protein 70 (HSP70) were detected. Morphological changes and structure of hippocampal CA1 region were observed under light microscope. RESULTS: Compared with the normal control group, contents of CRH and beta-EP significantly decreased in each radiation group. Serum contents of ACTH and beta-EP significantly increased in post-radiation day 1 and 7 groups (P < 0.05). Compared with radiation groups, beta-EP content in serum and pituitary significantly increased, and serum ACTH content significantly decreased in prevention groups (P < 0.05). Pituitary contents of CRH and beta-EP significantly increased in prevention groups. Serum contents of ACTH, beta-EP, and HSP70 were significantly lower in day 7 treatment group than post-radiation day 7 group (P < 0.05). Morphological results showed that pyramidal neurons in the hippocampal CA1 region arranged in disorder, with swollen cells, shrunken and condensed nucleus, dark dyeing cytoplasm, unclear structure. Vessels in partial regions were dilated with static blood; tissues were swollen and sparse. In prevention and treatment groups pathological damage of hippocampal CA1 region was obviously attenuated; neurons were arranged more regularly; swollen, pycnotic, or deleted neuron number were decreased; vascular dilatation and congestion was lessened. CONCLUSION: QG could affect HPAA function and activity of high intensity microwave radiated rats, showing certain preventive and therapeutic effects of microwave radiated rats by adjusting synthesis and release of partial bioactive peptides and hormones in HPAA, improving pathological injury in hippocampal CA1 region.

[The cardiac injury effect of microwave radiation on rabbit and its mechanism].

OBJECTIVE: To investigate the cardiac injury effect of different intensities microwave radiation on rabbits and its possible mechanism. METHODS: Rabbits were radiated by intensity of 50, 100, 150 and 200 mW/cm2 2450 MHz microwave for 20 min. 6 h after microwave radiation, the heart tissue was taken. ATP and mitochondria complex IV and V were measured in myocardial cells. The changes of myocardial tissue were observed by light microscopic. The expression of Caspase-3 and HSP 70 were detected by western blotting. RESULTS: The activity of ATP and mitochondria complex IV and V decreased significantly compared with normal control in cardiac tissue. 100, 150 and 200 mW/cm2 microwave radiation group vs. control group (P <0. 05). The HE staining result showed that myocardial cell appears edema, muscle fiber malalignment, cells appeared obvious injury. Results of western blotting showed that the expression of Caspase-3 and HSP 70 protein increased significantly in different dosage radiation group (P <0. 05). CONCLUSION: Microwave radiation has injury effect on rabbit heart. The possible mechanism may be related with inducing cell apoptosis by changing of stress level in myocardial cell.

Apoptosis induced by microwave radiation in pancreatic cancer JF305 cells.

New therapeutic approaches are needed to improve the survival rate from pancreatic cancer, one of the most lethal human malignancies. In this study, JF305 cells were treated with microwaves at doses of 2.5, 5.0, 10.0, 15.0, and 20.0 mW/cm(2) for 20 min. The inhibition of JF305 cell proliferation was tested using the MTT assay. Apoptotic cells were detected with Hoechst 33258 staining and a Nucleo-Counter NC-3000. The expression of apoptosis-related proteins was examined with Western blot. The results showed that microwaves inhibited the growth of JF305 cells in a dose-dependent manner, and caused morphological changes in apoptotic body formation. The percentages of apoptosis detected using annexin V-fluorescein isothiocyanate (FITC) were 4.0%, 10.0%, 12.0%, and 30.0% with the dosage of microwave (0, 5.0, 10.0, and 20.0 mW/cm(2)), respectively. Treatment with microwaves increased the activity of caspase-9 and caspase-3, down-regulated the expression of Bcl-2, and up-regulated the expression of Bax and CytoC. In addition, the expression level of p65 was increased whereas the level of IκBα down-regulated. Those results suggest that microwaves inhibit cell growth and induce apoptosis in JF305 cells through an NF-κB-regulated mitochondria-mediated pathway.

Effects of fibroblast growth factor 21 on cell damage in vitro and atherosclerosis in vivo.

Fibroblast growth factor 21 (FGF-21), which is a modulator of glucose and lipid homeostasis, acts as a novel therapeutic reagent for many metabolic perturbations. However, its potential as a treatment for cardiovascular disease, especially atherosclerosis (AS) has not been fully explored. Here, we report that recombinant FGF-21 improves resistance to cell damage from oxidative stress in vitro, and from atherosclerosis in vivo. Human umbilical vein endothelial cells (HUVECs) were induced with H2O2, followed by treatment with high purity recombinant FGF-21. The results indicated that FGF-21 significantly enhanced cell viability and decreased the degree of DNA fragmentation in HUVECs, as caused by H2O2 stress induction. Further studies revealed that FGF-21 inhibited H2O2-induced cell apoptosis by preventing the activation of mitogen-activated protein kinase (MAPK) signaling pathways. In an established rat model, FGF-21 dramatically improved the condition of atherosclerotic rats by decreasing serum levels of total triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and total cholesterol (TC), and by increasing the serum levels of high density lipoprotein cholesterol (HDL-C). FGF-21 also has antioxidant effects in the atherosclerotic rat, such that increased levels of superoxide dismutase, reduced glutathione, and reduced malondialdehyde were observed. These data provide novel insight into the potential use of FGF-21 in the prevention and treatment of human cardiovascular diseases.

[Proliferation inhibition and apoptosis induction of Juglone on human cervical cancer Caski cells].

OBJECTIVE: To explore the effects of Juglone on proliferation and apoptosis of human cervical cancer Caski cells, and to further study the related mechanism of cell apoptosis. METHODS: Cultured Caski cells were incubated with 20, 40, 60, 80 and 100 µmol/L juglone for 24 h. The proliferation of Caski cells was detected by methyl thiazolyl tetrazolium (MTT) assay. The cell apoptosis were detected by transmission electron microscope. The expression of Bcl-2 and Bax were detected by Western blot. RESULTS: MTT results showed that in different doses of juglone groups, the Caski cell growth was greatly inhibited (P < 0.05, P < 0.01) and showed dose dependent when compared with control group except 20 µmol/L. The IC50 of juglone was 42.4 µmol/L. After treatment on Caski cells with 40 µmol/L juglone, typical apoptosis characteristics was observed by transmission electronmicro scope. The expression of Bcl-2 was decreased while the expression of Bax was increased significantly when compared with control group (P < 0.05). CONCLUSION: Juglone significantly inhibits the proliferation and induces the apoptosis of Caski cells in vitro.

Nanoscale dihydroartemisinin@zeolitic imidazolate frameworks for enhanced antigiardial activity and mechanism analysis.

An artificial semisynthetic material can be derived from artemisinin (ART) called dihydroartemisinin (DHA). Although DHA has enhanced antigiardial potential, its clinical application is limited because of its poor selectivity and low solubility. The drug's absorption has a direct impact on the cell, and mechanism research is limited to its destruction of the cytoskeleton. In this study, we used the zeolitic imidazolate framework-8 and loaded it with DHA (DHA@Zif-8) to improve its antigiardial potential. DHA@Zif-8 can enhance cellular uptake, increase antigiardial proliferation and encystation, and expand the endoplasmic reticulum compared with the DHA-treated group. We used RNA sequencing (RNA-seq) to investigate the antigiardial mechanism. We found that 126 genes were downregulated and 123 genes were upregulated. According to the KEGG and GO pathway analysis, the metabolic functions in G. lamblia are affected by DHA@Zif-8 NPs. We used real-time quantitative reverse transcription polymerase chain reaction to verify our results using the RNA-seq data. DHA@Zif-8 NPs significantly enhanced the eradication of the parasite from the stool in vivo. In addition, the intestinal mucosal injury caused by G. lamblia trophozoites markedly improved in the intestine. This research provided the potential of utilizing DHA@Zif-8 to develop an antiprotozoan drug for clinical applications.

[Inhibitory effect of microwave radiation on proliferation of human pancreatic cancer JF305 cells and its mechanism].

OBJECTIVE: To investigate on the proliferation effect of different intensities 2450 MHz microwave radiation on human pancreatic cancer JF305 cells and its possible mechanism. METHODS: JF305 cells were radiated by intensity of 2.5, 5.0, 10.0, 15.0 and 20.0 mW/cm2 microwave for 20 min. The proliferation capacity of JF305 was measured by MTT assays, Annexin V-FITC and PI staining was used for detecting cell apoptosis. The activity of Caspase-3 was examined. The expressions of Caspase-3 and HSP 70 protein after the cell treatment with microwave were detected by Western blotting. RESULTS: After microwave radiation, the proliferation inhibition rates of JF305 cells were significantly higher compared with control group. Annexin V-FITC and PI staining result showed that microwave radiation could induce cell apoptosis. Caspase-3 increased after radiated by microwave, compared with control group (P < 0.05). Results of Western blotting showed that the expression of Caspase-3 and HSP 70 protein increased significantly in different dosage radiation group. CONCLUSION: Microwave radiation can inhibit the proliferation of JF305 cells, the possible mechanism may be related with inducing cell apoptosis by changing of stress level.

The Construction of Alkaline Phosphatase-Responsive Biomaterial and Its Application for In Vivo Urinary Tract Infection Therapy.

Urinary tract infections caused by urinary catheter implantations are becoming more serious. Therefore, the construction of a responsive antibacterial biomaterial that can not only provide biocompatible conditions, but also effectively prevent the growth and metabolism of bacteria, is urgently needed. In this work, a benzophenone-derived phosphatase light-triggered antibacterial agent is designed and synthesized, which is tethered to the biological materials using a one-step method for in vivo antibacterial therapy. This surface could kill gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). More importantly, because this material exhibited a zwitterion structure, it does not damage blood cells and tissue cells. When the bacteria interact with this surface, the initial fouling of the bacteria is reduced by zwitterion hydration. When the bacteria actively accumulate and metabolize to produce a certain amount of alkaline phosphatase, the surface immediately started the sterilization performance, and the bactericidal effect is achieved by destroying the bacterial cell membrane. In summary, an antibacterial biomaterial that shows biocompatibility with mammalian cells is successfully constructed, providing new ideas for the development of intelligent urinary catheters.

Self-assembly and self-delivery of the pure nanodrug dihydroartemisinin for tumor therapy and mechanism analysis.

Dihydroartemisinin (DHA), a plant-derived natural product, has recently been proven to be an effective therapeutic agent for cancer treatment. Nevertheless, the poor water solubility and low bioavailability of DHA seriously impede its clinical applications. Herein, a simple and green strategy based on the self-assembly of DHA was developed to synthesize carrier-free nanoparticles (NPs). The resulting nanodrug (DHA NPs) was formed by the self-assembly of DHA molecules via hydrogen bonding and hydrophobic interactions. The DHA NPs exhibited a near-spherical morphology with narrow size distribution, favorable drug encapsulation efficiency (>92%), excellent stability, and on-demand drug release behavior. Furthermore, the in vitro and in vivo experiments revealed that the DHA NPs exhibited significantly higher therapeutic efficacy than the DHA equivalent. In addition, we further explored the potential molecular mechanism of the DHA NPs by utilizing RNA-seq technology and western blotting analysis, which demonstrated that the p53 signaling pathway plays a crucial part in the process of inhibiting tumor cell growth and inducing apoptosis. This work not only reveals the rationale for developing pure nanodrugs via the self-assembly of natural small molecules for oncotherapy but also the investigation of the antitumor mechanism and provides novel theoretical support for the clinical usage of DHA.

Anticancer activity and mechanism of juglone on human cervical carcinoma HeLa cells.

Induction of apoptosis in tumor cells has become the major focus of anti-tumor therapeutics development. Juglone, a major chemical constituent of Juglans mandshurica Maxim, possesses several bioactivities, including anti-tumor. In the present study, HeLa cells were incubated with juglone at various concentrations. The proliferation inhibition of juglone on HeLa cells was tested by the MTT assay. Occurrence of apoptosis was detected by Hoechst 33258 staining, flow cytometry, and transmission electron microscopy. The expression of apoptotic-related proteins was examined by Western blot. The results showed that juglone inhibits the growth of HeLa cells in dose-dependent manner. Topical morphological changes of apoptotic body formation after juglone treatment were observed. The percentages of early apoptosis of Annexin V-FITC were 5.23%, 7.95%, 10.69%, and 20.92% with the concentrations of juglone (12.5, 25, 50, and 100 µmol/L), respectively. After cells were treated with juglone at the different dose for 24 h, the expression of Bcl-2 was significantly down-regulated and the expression of Bax was significantly up-regulated compared with the control. These events paralleled with activation of caspase-9, -8, -3, and PARP cleavage. The results suggest that juglone may be effective for the treatment of HeLa cells.

pH responsive zwitterionic-to-cationic transition for safe self-defensive antibacterial application.

Bacteria-induced infections have always been associated with various medical devices. The construction of an intelligent antimicrobial surface is an important challenge. In this study, we report the construction of a zwitterionic surface with good biocompatibility under physiological conditions and which shows an anti-adhesion effect on the original bacteria. Once the bacteria multiply, the acidic environment initiated by the bacteria will cause the amide bond on the surface to break, and the zwitterionic surface can be rapidly converted to a cationic bactericidal surface. Confocal laser scanning (CLSM) and scanning electron microscopy (SEM) show that the zwitterionic surface has efficient antibacterial activity with an anti-adhesion property while the pH-responsive transition to quaternary ammonium compounds with a germicidal surface in the acidic environment of bacterial metabolism aids the activity. Thus, the pH-responsive zwitterionic-to-cationic transition antibacterial design opens up new ideas for the efficient and safe application of cationic bactericides in clinical medical antibacterial materials.

Supramolecular hybrids of carbon dots and dihydroartemisinin for enhanced anticancer activity and mechanism analysis.

Dihydroartemisinin (DHA) has been regarded as a potential anticancer agent in recent years. Nevertheless, the clinical applications of DHA are seriously restricted as a result of its intrinsic characteristics, such as poor water solubility, instability, and fast clearance. Herein, a type of fluorescent nanoparticles was successfully fabricated via supramolecular assembling of carbon dots (CDs) and DHA. The formulated CDs-DHA fluorescent nanoparticles not only significantly improve the solubility and stability of DHA, but also possess favorable biocompatibility and pH-dependent drug release behavior. In particular, the hybrids of CDs and DHA as nanocarriers can effectively promote the endocytosis of DHA and exhibit enhanced antitumor effects compared with free DHA in vitro and in vivo. In addition, we also explore the possible action mechanism of CDs-DHA through flow cytometric assay, transfection and western blot analysis. The results indicate that CDs-DHA nanoparticles suppress the progression of hepatic carcinoma through inducing apoptosis and inhibiting glucose metabolism, and the mechanism is related to the downregulation of PKM2 expression and the suppression of the Akt/mTOR signaling pathway, which may provide a potential therapeutic target for hepatic carcinoma treatment. This work emphasizes the great potential of utilizing CDs as a safe and convenient platform to deliver DHA for efficient cancer therapy, and the study on the anticancer mechanism can also offer theoretical support for the clinical application of DHA.