Ferrate(VI)/percarbonate for the oxidation of micropollutants: Interactive activation and release of low-concentration hydrogen peroxide for efficient electron utilization.

A novel "ferrate/percarbonate (Fe(VI)/SPC) co-oxidation process" was used to treat ciprofloxacin (CIP) and various micropollutants (MPs), which owned better performance than mixture of Fe(VI), Na2CO3 and H2O2. The mechanism investigation found that the low-concentration H2O2 (1-2 µM) released by SPC can promote the high-valent iron intermediates (Fe(IV)/Fe(V)) of Fe(VI) to the MP oxidation, and Fe(VI) products can also activate SPC to produce hydroxyl radical (·OH). The interactive activation of Fe(VI) and SPC was realized, which retained the high selectivity of Fe(VI) to electron-rich pollutants, and also made up the oxidation of electron-deficient pollutants through •OH, improving the degradation effect of various MPs by 20-30%, and the rate constant was increased by 1 to 3 times. Moreover, non-purgeable organic carbon (NPOC) determination confirmed that â€¢OH participation reduced the NPOC value of CIP from 5.43 mg/L to 4.37 mg/L. The transformation pathway of CIP showed that Fe(VI)/SPC resulted in more hydroxylation intermediates of CIP than Fe(VI) alone. Acute toxicity assays found that the photoinhibition rate of CIP treated with Fe(VI) alone was 14.5%, while the sample treated with Fe(VI)/SPC showed no significant photoinhibition effect, which proved that the new process had good detoxification properties for CIP.

How Should We Activate Ferrate(VI)? Fe(IV) and Fe(V) Tell Different Stories about Fluoroquinolone Transformation and Toxicity Changes.

Many studies have investigated activation of ferrate (Fe(VI)) to produce reactive high-valent iron intermediates to enhance the oxidation of micropollutants. However, the differences in the risk of pollutant transformation caused by Fe(IV) and Fe(V) have not been taken seriously. In this study, Fe(VI)-alone, Fe3+/Fe(VI), and NaHCO3/Fe(VI) processes were used to oxidize fluoroquinolone antibiotics to explore the different effects of Fe(IV) and Fe(V) on product accumulation and toxicity changes. The contribution of Fe(IV) to levofloxacin degradation was 99.9% in the Fe3+/Fe(VI) process, and that of Fe(V) was 89.4% in the NaHCO3/Fe(VI) process. The cytotoxicity equivalents of levofloxacin decreased by 1.9 mg phenol/L in the Fe(IV)-dominant process while they significantly (p < 0.05) increased by 4.7 mg phenol/L in the Fe(V)-dominant process. The acute toxicity toward luminescent bacteria and the results for other fluoroquinolone antibiotics also showed that Fe(IV) reduced the toxicity and Fe(V) increased the toxicity. Density functional theory calculations showed that Fe(V) induced quinolone ring opening, which would increase the toxicity. Fe(IV) tended to oxidize the piperazine group, which reduced the toxicity. These results show the different-pollutant transformation caused by Fe(IV) and Fe(V). In future, the different risk outcomes during Fe(VI) activation should be taken seriously.

Snail-inspired AFG/GelMA hydrogel accelerates diabetic wound healing via inflammatory cytokines suppression and macrophage polarization.

Diabetic foot ulcers (DFUs) are a severe and rapidly growing diabetic complication, but treating DFUs remains a challenge for the existing therapies are expensive and highly non-responsive. Recently, we discovered that a natural adhesive from snail mucus can promote skin wound healing. Herein, inspired by the finding, we developed a double-network hydrogel biomaterial that composed of snail glycosaminoglycan (AFG) and methacrylated gelatin (GelMA), in which AFG is the main bioactive component of snail mucus and GelMA provides a scaffold mimicking the proteins in snail mucus. The biomimetic hydrogel exhibited strong tissue adhesion, potent anti-inflammatory activity, and excellent biocompatibility. The biodegradable AFG/GelMA hydrogel markedly promoted chronic wound healing in both STZ-induced type 1 diabetic rat and db/db mouse models after a single treatment. Further mechanistic research showed that the hydrogel significantly attenuated inflammation by sequestrating pro-inflammatory cytokines, as well as downregulated their expression by inhibiting NF-ĸB signaling pathway, and it can also promote macrophage polarization to M2 phenotype. Taken together, the bioinspired hydrogel can effectively promote the transition of chronic wounds from inflammation to proliferation stage. These data suggest that the AFG/GelMA hydrogel is a promising therapeutic biomaterial for the treatment of chronic diabetic wounds.

Efficient wastewater disinfection by raised 1O2 yield through enhanced electron transfer and intersystem crossing via photocatalysis of peroxymonosulfate with CuS quantum dots modified MIL-101(Fe).

Peroxymonosulfate (PMS)-based photocatalysis is a promising alternative approach for wastewater disinfection. Singlet oxygen (1O2) is sensitive and efficient for bacterial inactivation. This study developed a 1O2-predominated PMS disinfection technique under visible light with CuS quantum dots (QDs) modified MIL-101(Fe) (CSQDs@MF). CuS QDs modification greatly enhanced the 1O2 quantum yield by 80% than that of MIL-101(Fe). Photoelectricity and photoluminescence tests demonstrated that both the enhanced electron transfer and energy transfer were responsible for improved 1O2 generation in Vis/PMS/CSQDs@MF system. The system took 60 min to inactivate 7.5-log E. coli, and it could be applied in a broad pH and dissolve oxygen range. Bacterial inactivation mechanism suggested that 1O2 attacked cell membrane first, then induced oxidative stress, up-regulated intracellular ROS level, eventually broke DNA strand. The system showed good disinfection performance on Gram-positive B. subtilis and fecal coliforms in practical wastewater, implying it is a promising alternative disinfection technology for wastewater treatment.

Optimization of the ultrasound-assisted aqueous enzymatic extraction of Pinus koraiensis nuts oil by response surface methodology.

Response surfaces methodology was established in order to optimize ultrasound-assisted aqueous alkaline protease extraction parameters of Pinus koraiensis nuts oil (PNO) in this short communication. On the oil yield, the impacts of single factors were studied. The solid-liquid ratio, enzyme concentration, enzyme hydrolysis temperature, and enzyme hydrolysis duration were chosen for further optimization of the extraction process utilizing a Box-Behnken design based on statistical significance analysis. Under ideal extraction conditions, a maximum oil recovery of 68.35% was achieved: solid-liquid ratio, enzyme concentration, enzyme hydrolysis temperature, and enzyme hydrolysis duration were 1:5 (g/mL), 3.23 mg/g, 44 °C, and 2.84 h, respectively. Furthermore, physicochemical properties testing revealed that the oil was of higher quality than other approaches. Meanwhile, the DPPH radical-scavenging activities increased with increased content compared to olive oil, with an IC50 value of 0.082 mg/mL. The method has a lot of potential when it comes to extracting oils from plants.

A facile method for anti-cancer drug encapsulation into polymersomes with a core-satellite structure.

Polymersomes possess the self-assembly vesicular structure similar to liposomes. Although a variety of comparisons between polymersomes and liposomes in the aspects of physical properties, preparation and applications have been elaborated in many studies, few focus on their differences in drug encapsulation, delivery and release in vitro and in vivo. In the present work, we have provided a modified direct hydration method to encapsulate anti-cancer drug paclitaxel (PTX) into PEG-b-PCL constituted polymersomes (PTX@PS). In addition to advantages including narrow particle size distribution, high colloid stability and moderate drug-loading efficiency, we find that the loaded drug aggregate in small clusters and reside through the polymersome membrane, representing a unique core-satellite structure which might facilitate the sustained drug release. Compared with commercial liposomal PTX formulation (Lipusu®), PTX@PS exhibited superb tumor cell killing ability underlain by multiple pro-apoptotic mechanisms. Moreover, endocytic process of PTX@PS significantly inhibits drug transporter P-gp expression which could be largely activated by free drug diffusion. In glioma mice models, it has also confirmed that PTX@PS remarkably eradicate tumors, which renders polymersomes as a promising alternative to liposomes as drug carriers in clinic.

Adding liver R2* quantification to proton density fat fraction MRI of vertebral bone marrow improves the prediction of osteoporosis.

OBJECTIVES: To assess the predictive value of the combination of bone marrow (BM) proton density fat fraction (PDFF) and liver R2* for osteopenia and osteoporosis and the additional role of liver R2*. METHODS: A total of 107 healthy women were included between June 2019 and January 2021. Each participant underwent dual-energy X-ray absorptiometry (DXA) and chemical shift-encoded 3.0-T MRI. PDFF measurements were performed for each lumbar vertebral body, and R2* measurements were performed in liver segments. Agreement among measurements was assessed by Bland-Altman analysis. Receiver operating characteristic (ROC) curves were generated to select optimised cut-offs for BM PDFF and liver R2*. Univariable and multivariable logistic regressions were performed. The C statistic and continuous net reclassification improvement (NRI) were adopted to explore the incremental predictive ability of liver R2*. RESULTS: Bone mass decreased in 42 cases (39.3%) and nonbone mass decreased in 65 cases (60.7%). There were significant differences among the age groups, menopausal status groups, PDFF > 45.0% groups, and R2* > 67.7 groups. Each measurement had good reproducibility. The odds ratios (95% CIs) were 4.05 (1.22-13.43) for PDFF and 4.34 (1.41-13.35) for R2*. The C statistic (95% CI) without R2* was 0.888 (0.827-0.950), and with R2* was 0.900 (0.841-0.960). The NRI resulting from the combination of PDFF and R2* was 75.6% (p < 0.01). CONCLUSION: The predictive improvement over the use of BM PDFF and other traditional risk factors demonstrates the potential of liver R2* as a biomarker for osteopenia and osteoporosis in healthy women. KEY POINTS: • Liver R2* is a biomarker for the assessment of osteopenia and osteoporosis. • Liver R2* improved the ability to predict osteopenia and osteoporosis. • The intra- and interobserver measurements showed high agreement.

A cationic cyclodextrin derivative-lipid hybrid nanoparticles for gene delivery effectively promotes stability and transfection efficiency.

Genetic medicines hold great promise for treatment of a number of diseases; however, the development of effective gene delivery carrier is still a challenge. The commonly used gene carrier liposomes and cationic polymers have limited their clinical application due to their respective disadvantages. Lipid-polymer hybrid nanoparticles (LHNPs) are novel drug delivery system that exhibit complementary characteristics of both polymeric nanoparticles and liposomes. In this account, we developed the α-cyclodextrin-conjugated generation-2 polyamidoamine dendrimers-lipids hybrid nanoparticles (CDG2-LHNPs) for gene delivery. The pDNA/CDG2-LHNPs was stable during 15 days of storage period both at 4 °C, 25 °C, and 37 °C, whereas the particle size of pDNA/CDG2 and pDNA/liposomes dramatically increased after storage at 4 °C for 8 h. CDG2-LHNPs showed significantly superior transfection efficiencies compared to either CDG2 or liposomes. The mechanism of high transfection efficiency of pDNA/CDG2-LHNPs was further explored using pharmacological inhibitors chlorpromazine, filipin, and cytochalasion D. The result demonstrated that cell uptake of pDNA/CDG2-LHNPs was mediated by clathrin-mediated endocytosis (CME), caveolae-mediated endocytosis (CvME), and macropinocytosis together. pDNA/CDG2-LHNPs were more likely be taken up by cells through CvME, which avoided lysosomal degradation to a large extent. Moreover, the liposome component of pDNA/CDG2-LHNPs increased its cell uptake efficiency, and the CDG2 polymer component increased its proton buffer capacity, so the hybrid nanoparticles taken up by CME could also successfully escape from the lysosome. CDG2-LHNPs with stability and high-transfection efficiency overcome the shortcomings of liposomes and polymers applied separately, and have great potential for gene drug delivery.

Fatty acid synthase (Fasn) inhibits the expression levels of immune response genes via alteration of alternative splicing in islet cells.

BACKGROUND: Increasing evidence has shown that fatty acid synthase (Fasn) is associated with diabetes mellitus (DM) and insulin resistance, however, it remains unclear how Fasn upregulation leads to dysregulation of energy homeostasis in islet cells. Consequently, uncovering the function of Fasn in islet cells. Consequently, uncovering the function of FASN in islet cells is immensely important for finding a treatment target. AIM: In this study, we elucidated the biological function of Fasn on the target genes in a rat insulinoma INS-1 cell line. METHODS: We created a Fasn overexpressing rat insulinoma cell line (Fasn-OE), and performed bulk RNA-sequencing (RNA-seq) experiments on Fasn-OE and INS-1 (control) cells. We first identified differentially expressed genes (DEGs) using Bioconductor package edgeR, and then discovered enriched gene ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways using the KEGG Orthology Based Annotation System (KOBAS) 2.0 web server. Furthermore, we identified alternative splicing events (ASEs) and regulated alternative splicing events (RASEs) by applying the ABLas pipeline. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used for validation of selected differentially expressed genes (DEGs) and Fasn-regulated alternative splicing genes (RASGs). RESULTS: In this study we found that Fasn overexpression led to significant changes of gene expression profiles, including downregulations of mRNA levels of immune related genes, including Bst2, Ddit3, Isg15, Mx2, Oas1a, Oasl, and RT1-S3 in INS-1 cell line. Furthermore, Fasn positively regulated the expression of transcription factors such as Fat1 and Ncl diabetes-related genes. Importantly, Fasn overexpression to result in alternative splicing events including in a metabolism-associated ATP binding protein mRNA Abcc5. In Gene Ontology analysis, the downregulated genes in Fasn-OE cells were mainly enriched in inflammatory response and innate immune response. In Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the downregulated genes were mainly enriched in TNF signaling pathway and cytokine-mediated signaling pathways. CONCLUSIONS: Our findings showed that upregulation of Fasn may play a critical role in islet cell immunmetabolism via modifications of immune/inflammatory related genes on transcription and alternative splicing level, which provide novel insights into characterizing the function of Fasn in islet cell immunity and for the development of chemo/immune therapies.

The pH-triggered polyglutamate brush co-delivery of MDR1 and survivin-targeting siRNAs efficiently overcomes multi-drug resistance of NSCLC.

Multi-drug resistance (MDR) is one of the major challenges in the successful chemotherapy of non-small cell lung cancer (NSCLC). Although RNA interference (RNAi) has been widely used to silence resistance-related genes, the effect remains unsatisfactory. In this study, we attempted to overcome MDR of NSCLC by simultaneously interfering with two RNAs that have different functions. A new pH-triggered polyglutamate brush polymer dimethylmaleic anhydride-poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (DMA-mPEG-b-PG-g-spermine, DPPGS) was designed and synthesized. The DPPGS/small interfering RNA (siRNA) complex nanoparticles (DPPGSN) were prepared. The results demonstrated that DPPGSN could be transformed from a negatively charged form into a positively charged form in the slightly acidic tumor extracellular environment. The siRNA targeting MDR1 mRNA (siMDR1) and siRNA targeting survivin mRNA (siSurvivin) could be efficiently co-delivered by DPPGS to simultaneously interfere with two genes (p < 0.01). Furthermore, DPPGS co-delivery of siMDR1 and siSurvivin lowered the IC50 value of cisplatin (DDP) in A549/DDP (p < 0.01) cells and increased the apoptosis rate of the cells (p < 0.01). Therefore, co-delivery of siMDR1 and siSurvivin using DPPGS would be a promising approach for overcoming MDR of NSCLC.

Construction of Bi2O3/CuNiFe LDHs composite and its enhanced photocatalytic degradation of lomefloxacin with persulfate under simulated sunlight.

Advanced oxidation methods based on photocatalysis and sulfate radicals have attached most interest towards contaminant degradation. However, there are a lack of coupling two methods in the field of pollutant degradation. In the present study, a new Bi2O3/CuNiFe LDHs composite was fabricated and it could efficiently activate persulfate (PS) for lomefloxacin (LOM) decomposition under simulated sunlight, in which 84.6% of LOM (10 mg·L-1) was degraded over 40 min with 0.4 g·L-1 of Bi2O3/CuNiFe LDHs composite and 0.74 mM of PS at natural pH. In addition, the Bi2O3/CuNiFe LDHs composite possessed good reusability and stability at least four runs. Moreover, active radical scavenging experiments indicated that hydroxyl radicals (HO·), sulfate radicals (SO4·-), superoxide radicals (O2·-) and hole (h+) were the main radicals under LOM degradation process. Subsequently, the possible degradation intermediates were determined and the decomposition pathways were put forward. At the same time, activated sludge inhibition experiments were performed to assess the variation of toxicity of LOM and its degradation intermediates during oxidation. Finally, possible reaction mechanism of Bi2O3/CuNiFe LDHs composite for PS activation under simulated sunlight was proposed.

Precise structures and anti-intrinsic tenase complex activity of three fucosylated glycosaminoglycans and their fragments.

Fucosylated glycosaminoglycan (FG), a glycosaminoglycan derivative containing distinct sulfated fucose (FucS) branches, displays potent anticoagulant activity by inhibiting the intrinsic tenase complex (iXase). Herein, AmFG, SvFG and HaFG from three species of sea cucumbers were isolated and depolymerized by ß-eliminative cleavage. Three series of fragments, A1-A4, S1-S4 and H1-H4, were purified from the depolymerized FGs. Based on structural analysis of these fragments, three FGs were deduced as -{→4)-[L-FucS-α(1→3)]-D-GlcA-ß(1→3)-D-GalNAc4S6S-ß(1}n-. The structures differed in sulfation types of FucS, namely, most of FucS in AmFG was Fuc3S4S, but the FucS in SvFG was Fuc2S4S, while the FucS in HaFG was Fuc3S4S, Fuc2S4S and Fuc4S. However, all FucS branches attached to C-3 of GlcA as monosaccharides. Anticoagulant and anti-iXase assays showed the octasaccharide is the minimum fragment for potent anticoagulant activity via anti-iXase irrespective of FucS types. Among FG fragments with same degree of polymerization, oligosaccharides containing Fuc2S4S had more potent anti-iXase activity.

Oral administration of Urtica macrorrhiza Hand.-Mazz. polysaccharides to protect against cyclophosphamide-induced intestinal immunosuppression.

As a strategy to prevent the well-known immunosuppressant effects of cyclophosphamide (CY), the immunomodulatory activity of the polysaccharide isolated from Urtica macrorrhiza Hand.-Mazz. (UMHMPS) was investigated in the present study. The chemical properties of UMHMPS, including total carbohydrates, uronic acid, protein contents, monosaccharide compositions, molecular weight and structural confirmation, were investigated. The immunomodulatory activity of UMHMPS was evaluated using a CY-induced immunosuppression mouse model. The results revealed that UMHMPS, which is composed of rhamnose, gluconic acid, galactose acid, galactose and xylose, exhibited potent immunomodulatory activity and low toxicity in mice. It increased the secretions of secretory immunoglobulin A, interferon (IFN)-γ and interleukin (IL)-4, and maintained the balance of the ratios of IFN-γ/IL-4 and cluster of differentiation (CD)3+/CD19+ cells in Peyer's patches. Furthermore, it increased the expression of Toll-like receptor (TLR)-4, indicating that TLR4 may be one of the receptors of UMHMPS. Therefore, the present study provides evidence for the potential use of UMHMPS as an immune enhancement drug in chemotherapy.

Glutamine addiction activates polyglutamine-based nanocarriers delivering therapeutic siRNAs to orthotopic lung tumor mediated by glutamine transporter SLC1A5.

Many human cancer cells exhibit an oncogenetic-driven addiction to glutamine (Gln) as rapidly proliferating cancer cells consume Gln at a dramatically increased rate compared to normal cells. Tumor cells, therefore, compete with host cells for Gln, which causes Gln to flux from normal tissues to the tumor. We have developed and characterized a Gln macromolecular analog polyglutamine (PGS) for the delivery of gene regulators, such as siRNAs, in our previous works. Here, we hypothesize that PGS can utilize the Gln transporter SLC1A5 to specifically deliver therapeutic compounds to Gln-addicted cancer cells. Compared to human lung fibroblast HLF cells, cisplatin-resistant human lung adenocarcinoma A549/DDP cells significantly overexpress SLC1A5, which has a high binding affinity to PGS, as confirmed through molecular docking analysis. Due to the differences in Gln metabolism between malignant and normal cells, PGS/siRNA complexes were remarkably increased in cancer cells, especially when cells were deprived of Gln, which mirrors the conditions that are commonly found in a tumor microenvironment. Furthermore, we identified that chemical and genetic inhibition of Gln transporter SLC1A5 reduced the cellular internalization of PGS/siRNA complexes, suggesting a critical role for SLC1A5 in PGS uptake in cells. In turn, PGS upregulated SLC1A5 expression. Increased uptake of PGS complexes profoundly decreased intracellular Gln levels. Decreased Gln caused a moderate reduction in cell growth. To restore drug sensitivity and further enhance anti-tumor effects, the hybrid siRNAs anti-Survivin and anti-MDR1 (siSM), as model therapeutics, were administered through the PGS delivery system, which resulted in knockdown of Survivin and MDR1 and further sensitized cancer cells to the drug cisplatin (DDP). Since PGS complexes administered i.v. mostly accumulated in the lung parenchyma, a lung orthotopic tumor model was established to evaluate their inhibitory effects on tumors in the lungs. PGS/siSM comparably decreased the rate of tumor growth, while concurrent administration of PGS/siSM and DDP enhanced this effect and insignificantly improved life span. Consistent with our hypothesis, this study demonstrated that PGS mimicked Gln in the SLC1A5 pathway and selectively ferried therapeutics to Gln-addicted cancer cells. Our findings identified a new lung cancer targeting strategy based on Gln metabolism and can be used as a drug/gene delivery system.

Synthesis of Magnetic CoFe2O4 Nanoparticles and Their Efficient Degradation of Diclofenac by Activating Persulfate via Formation of Sulfate Radicals.

In this study, magnetic CoFe2O4 nanoparticles were synthesized by hydrothermal method by using ferric nitrate and cobalt nitrate as raw materials. Subsequently, physicochemical properties of the resulting CoFe2O4 nanoparticles were systematically studied by scanning electron microscope, X-ray diffraction, N2 adsorption/desorption, Fourier transformation infrared spectroscopy and Vibration sample magnetometer measurement. Results indicated that CoFe2O4 nanoparticles with cubic spinel structure possessed an average diameter of 6.9 nm, specific surface area of 103.48 m2 · g-1, saturation magnetization of 54.65 A · m2(emu · g-1) and coercivity of 1.76×104 A · m-1. Furthermore, scavenging experiments revealed that sulfate radicals (.SO-4) was the main active species derived from persulfates, in which 72.3% of diclofenac could be degraded within 30 min treatment. This study provides a promising strategy to synthesize versatile catalyst which would be potentially applied in pharmaceutical wastewater purification.

Noninvasive detection of matrix metalloproteinase-9 in atherosclerotic lesions using technetium-99m-labeled single-photon emission computed tomography in vivo.

OBJECTIVE: Previous studies have suggested that matrix metalloproteinase (MMP) inhibitor uptake may offer a precise estimation of MMP activity in atherosclerotic lesions. In this study, we explored the feasibility of noninvasive detection of MMP-9 activity using technetium-99m-labeled matrix metalloproteinase-9 antibody (Tc-McAb) in vivo. METHODS: ApoE-deficient (ApoE) atherosclerosis mice models (n=10) were induced through a high-cholesterol diet following ligation of their left common carotid artery. After 4 weeks, the models were verified through proton density-weighted and T2-weighted images obtained by MRI. C57BL/6 sham mice (n=8) were used as controls. In addition, normal mice (n=20) were used to characterize blood clearance. After radiolabeled McAb administration, single-photon emission computed tomography (SPECT) was performed. Subsequently, left common carotid arteries were harvested for ex-vivo autoradiograph imaging. Then, morphology and activity assays of MMP-9 were histologically and immunohistochemically examined. RESULTS: MRI showed higher signal intensities in the left common carotid arteries with irregular stenoses in the lumen of blood vessels in atherosclerosis mice models in vivo. Atherosclerotic lesions on left common carotid artery specimens were also clearly visualized using SPECT 2 h after Tc-McAb administration in vivo. Note that the radiochemistry purity of the Tc-McAb used was 85-95%. Biodistribution studies have shown that the clearance of Tc-McAb from blood was rapid. In addition, atherosclerotic lesions were clearly visualized on radioautography film shadows ex vivo. CONCLUSION: MMP-9 activities within the atherosclerotic lesions were noninvasively detected using Tc-labeled SPECT in vivo.

Augmented anti-tumor activity of NK-92 cells expressing chimeric receptors of TGF-ßR II and NKG2D.

The capacity of natural killer (NK) cells to kill tumor cells without specific antigen recognition provides an advantage over T cells and makes them potential effectors for tumor immunotherapy. However, the efficacy of NK cell adoptive therapy can be limited by the immunosuppressive tumor microenvironment. Transforming growth factor-ß (TGF-ß) is a potent immunosuppressive cytokine that can suppress NK cell function. To convert the suppressive signal induced by TGF-ß to an activating signal, we genetically modified NK-92 cells to express a chimeric receptor with TGF-ß type II receptor extracellular and transmembrane domains and the intracellular domain of NK cell-activating receptor NKG2D (TN chimeric receptor). NK-92 cells expressing TN receptors were resistant to TGF-ß-induced suppressive signaling and did not down-regulate NKG2D. These modified NK-92 cells had higher killing capacity and interferon γ (IFN-γ) production against tumor cells compared with the control cells and their cytotoxicity could be further enhanced by TGF-ß. More interestingly, the NK-92 cells expressing TN receptors were better chemo-attracted to the tumor cells expressing TGF-ß. The presence of these modified NK-92 cells significantly inhibited the differentiation of human naïve CD4+ T cells to regulatory T cells. NK-92-TN cells could also inhibit tumor growth in vivo in a hepatocellular carcinoma xenograft tumor model. Therefore, TN chimeric receptors can be a novel strategy to augment anti-tumor efficacy in NK cell adoptive therapy.

Erythropoietin reduces apoptosis of brain tissue cells in rats after cerebral ischemia/reperfusion injury: a characteristic analysis using magnetic resonance imaging.

Some in vitro experiments have shown that erythropoietin (EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion. To validate this hypothesis, we established a rat model of focal cerebral ischemia/reperfusion injury, and treated with intra-cerebroventricular injection of EPO (5,000 U/kg) 20 minutes before injury. Brain tissue in the ischemic injury zone was sampled using MRI-guided localization. The relative area of abnormal tissue, changes in PWI and DWI in the ischemic injury zone, and the number of apoptotic cells based on TdT-mediated dUTP-biotin nick end-labeling (TUNEL) were assessed. Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI, increases cerebral blood volume, and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion. The experiment provides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury.

Highly stable polyglutamate derivatives/siRNA polyplex efficiently down-relegate survivin expression and augment the efficacy of cisplatin.

RNA interfere (RNAi)-based technology holds great promise in cancer treatment. The use of small interfering RNA (siRNA), however, is hampered by its low delivery efficiency in vivo when they are diluted in blood biofluids and in the presence of serum and salt. In this study, we developed the polyglutamate derivative polymer brush, poly(ethyleneglycol) monomethyl ether-b-polyglutamate-g-spermine (mPEG-b-PG-g-spermine, PPGS), which could efficiently deliver survivin-siRNA under ultra-high dilution and in the presence of salt (NaCl 150mM) and serum (10% FBS), most likely due to its PEG-shelled polymer brush structure. On the contrary, aggregation occurred when PEI/siRNA polyplex dispersed in saline and serum-containing media and PEI polyplex dissociated after making a 256-fold dilution. PPGS/si-survivin polyplex exhibited high cellular uptake efficiency and efficiently down-regulated the expression of survivin mRNA in the cisplatin-resistance of non-small cell human lung adenocarcinoma (A549/DDP) cells in the presence of serum. However, either PEI polyplex or Lipofectmine 2000 complex was unstable in serum and salt-containing media and at high dilution rates, which resulted in their dramatical decrease of cellular uptake and gene-silencing efficiency in these conditions. The PPGS/si-survivin polyplex also exhibited synergistic effects of killing the cancer cells by combination treatment with cisplatin. Therefore, the PPGS gene carrier showed great potential in systemic siRNA delivery, and its combination with chemotherapeutic drug is promising in treating drug resistant cancers.

Endothelial cell-targeted pVEGF165 polyplex plays a pivotal role in inhibiting intimal thickening after vascular injury.

Upregulation of vascular endothelial growth factor (VEGF) expression can inhibit intimal thickening after vascular injury. However, the lack of efficient gene delivery systems leads to insufficient VEGF expression, which prevents its application in gene therapy. In the present study, to improve the delivery of the plasmid vector with the VEGF gene (pVEGF165) to the injured vessel wall, we explored the potentially important difference between endothelial cell-targeted and nontargeted polymeric carriers. The αvß3 integrin is overexpressed on activated endothelial cells but not on normal quiescent vessels. In this study, CDG2-cRGD, synthesized by conjugating an αvß3 integrin-binding cyclic arginylglycylaspartic acid (cRGD) peptide with the Generation 2 polycation polyamidoamine (PAMAMG2)-g-cyclodextrin (termed as CDG2), was developed as a targetable carrier. It was observed that the specific integrin-ligand interactions greatly enhanced cellular internalization of CDG2-cRGD in human umbilical vein endothelial cells (HUVECs), which are notoriously difficult to transfect. Consequently, HUVECs were found to show remarkably high levels of VEGF165 expression induced by the CDG2-cRGD polyplex. Interestingly, VEGF165 overexpression in vivo was more complex than that in vitro, and in vivo assays demonstrated that the stimulus response to balloon injury in arteries could obviously upregulate VEGF165 expression in the saline-treated group, although it was not enough to prevent intimal thickening. In gene-transfected groups, intravascular delivery of pVEGF165 with the CDG2-cRGD polyplex into rabbits after vascular injury resulted in a significant inhibition of intimal thickening at 4 weeks, whereas the low therapeutic efficacy in the nontargeted CDG2-treated group was only comparable to that in the saline-treated group. It is becoming clear that the conflicting results of VEGF165 gene therapy in two gene-transfected groups are reflective of the pivotal role of the cRGD-conjugated carriers in achieving the beneficial therapeutic effects of vascular gene therapy.