Bioinspired Polydopamine-Coated Hemoglobin as Potential Oxygen Carrier with Antioxidant Properties.

Oxidative side reaction is one of the major factors hindering the development of hemoglobin-based oxygen carriers (HBOCs). To avoid the oxidative toxicity, we designed and synthesized polydopamine-coated hemoglobin (Hb-PDA) nanoparticles via simple one-step assemblage without any toxic reagent. Hb-PDA nanoparticles showed oxidative protection of Hb by inhibiting the generation of methemoglobin (MetHb) and ferryl (Fe IV) Hb, as well as excellent antioxidant properties by scavenging free radicals and reactive oxygen species (ROS). Interestingly, the scavenging rate of Hb-PDA nanoparticles for ABTS+ radical is at most 89%, while for DPPH radical it reaches 49%. In addition, Hb-PDA efficiently reduced the intracellular H2O2-induced ROS generation. Moreover, Hb-PDA nanoparticles exhibited high oxygen affinity, low effect on blood constituents, and low cytotoxicity. The results indicate that polydopamine-coated hemoglobin might be a promising approach for constructing novel oxygen carriers with the capacity to reduce oxidative side reaction.

Enhanced Germicidal Efficacy by Co-Delivery of Validamycin and Hexaconazole with Methoxy Poly(ethylene glycol)-Poly(lactide-co-glycolide) Nanoparticles.

Co-delivery system has been proposed in pharmaceutical field aim to synergistic treatments. The combination formulation is also important in traditional pesticides formulations based on the low pest resistance risk and wide fungicidal spectrum. However, co-delivery nanoparticles (NPs) tend to be more environmentally friendly for the sustained-release behaviour and none of toxic organic solvents or dusts. Hence, we constructed co-delivery NPs which could delivery two kinds of pesticides, which function was similar with pesticides combination formulation. The co-delivery NPs of validamycin and hexaconazole were prepared with the amphiphilic copolymer methoxy poly(ethylene glycol)- poly(lactide-co-glycolide) (mPEG-PLGA) used an improved double emulsion method. The chemical structure of mPEG-PLGA copolymer was confirmed using fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance spectroscopy (NMR). The co-delivery NPs all exhibited good size distribution and held sustained-release property. Germicidal efficacy of the co-delivery NPs against Rhizoctonia cerealis was also studied. The germicidal efficacy of co-delivery NPs against Rhizoctonia cerealis was better than that of traditional pesticides formulation. In addition, co-delivery NPs showed a lasting impact against Rhizoctonia cerealis.

Size-Dependent Effect of Prochloraz-Loaded mPEG-PLGA Micro- and Nanoparticles.

As a controlled release formulation, polymer-based pesticide particle, provide an effective approach to achieve the target crop sites of increasing the pesticide utilization and reducing side effects. The particle size impacts on the dispersibility, pesticide loading content, control effect, etc. It is essential to investigate size-dependent effect. Hence, size-dependent effect of polymer-based pesticide particle was studied systematically in this paper. The biodegradable mPEG-PLGA copolymer with suitable molecular weight (45 KDa) was selected as carrier. Prochloraz-loaded mPEG-PLGA particles with different sizes (190.7 nm, 708.8 nm and 3980.0 nm) were constructed by emulsion/solvent evaporation method based on the same carrier. With the constant mass ratio of copolymer/prochloraz, as the particle size became large, the prochloraz loading content increased, and prochloraz released speed decreased. All prochloraz-loaded particles showed a sustained-release process and sustained impact against the Fusarium graminearum. Among the prochloraz-loaded mPEG-PLGA particles, the 190.7 nm particles exhibited the best germicidal efficacy in two weeks. Hence, the smaller size particles hold a better control efficacy in short time.

[Dynamic changes in programmed death-1 expression on the surface of T cells in chronic hepatitis C patients undergoing interferon therapy].

OBJECTIVE: To investigate the dynamic changes that occur in T cell subsets, particularly involving the surface expression of programmed death 1 (PD-1), in response to pegylated (Peg)-interferon (IFN) a-2a therapy in patients with chronic hepatitis C virus (HCV) infection. METHODS: Twenty-five patients with HCV genotype 1b chronic infection and 10 healthy controls were enrolled in the study. All the HCV patients received combination antiviral therapy of Peg-IFNa-2a (180 mug/week) plus ribavirin. At treatment weeks 0 (baseline), 4, 12, 24 and 48, the level of PD-1 protein expression on the surface of total peripheral CD8+ and CD4+ T cells was determined by flow cytometry and the level of PD-1 mRNA expression in peripheral blood mononuclear cells (PBMCs) was determined by reverse transcription-polymerase chain reaction. Independent student's t-test were used to compare mean values between the two groups, repeat measure variance analysis was used to compare mean values among multiple groups, and Pearson's correlation coefficient was used to assess correlation significance. RESULTS: Over the course of antiviral therapy, the proportions of CD4+ T cells and CD8+ T cells, as well as the CD4+/CD8+ ratio, increased (F = 81.23, 39.28, and 7.01 respectively; all P less than 0.01). In contrast, the PD-1 protein expression frequency on CD4+ T cells and CD8+ T cells significantly declined (F = 100.11 and 158.40 respectively; all P less than 0.01). The PD-1-mRNA expression level in PBMCs was: 1.40+/-0.26 at baseline, 1.30+/-0.27 at week-4, 1.14+/-0.18 at week-12, 1.06+/-0.26 at week-24, and 0.83+/-0.25 at week-48 (F = 20.09; P less than 0.01). A positive correlation existed between the PD-1 protein expression frequencies on CD4+ T cells and CD8+ T cells and the HCV RNA load detected at baseline (r = 0.82 and 0.75 respectively; all P less than 0.01). CONCLUSION: The ability of Peg-IFN-a-2a-based antiviral therapy to suppress HCV replication may involve reduction of PD-1 protein expression on the surface of CD8+ T cells and CD4+ T cells.

Improved efficacy by individualized combination therapy with Peg IFN-a 2a and ADV in HBeAg positive chronic hepatitis B patients.

BACKGROUND/AIMS: Monotherapy with pegylated interferon alpha (Peg-IFNa) or adefovir dipivoxil (ADV) to HBeAg-positive chronic hepatitis B (CHB) patients has limited effects. This study aims to evaluate therapeutic efficacy and safety of individualized combination therapy with Peg-IFNa and ADV. METHODOLOGY: HBeAg-positive CHB patients (n=160) were enrolled in this multi-center, prospective, randomized, 'real-life' cohort study, of which received Peg IFNa-2a monotherapy or combination therapy with ADV base on the baseline features and treatment response. RESULTS: At week 24, percentages of ALT normalization, HBV DNA undetectable were both higher in individualized treatment group (ITG, 57.50%, 43.75%) than that in standard treatment group (STG, 40.00%, 27.50%; p=0.027, 0.032). The superiority of HBeAg clearance and seroconversion rates in ITG maintained from treatment termination (63.75%, 56.25%) to 48 weeks follow-up (57.50%, 53.75%). At week 96 the combined response rates were 46.25% in ITG compared with 30.00% in STG (p=0.034). Furthermore, there was no statistically significant difference in relapse rates and adverse events between the two groups. CONCLUSIONS: Individualized combination therapy can achieve higher antiviral response rates. In particular, it can accelerate undetectable HBV DNA and elevate HBeAg clearance/seroconversion rates to a greater degree than Peg-IFNa-2a monotherapy.

Harnessing immune response using reactive oxygen Species-Generating/Eliminating inorganic biomaterials for disease treatment.

With the increasing understanding of various biological functions mediated by reactive oxygen species (ROS) in the immune system, a number of studies have been designed to develop ROS-generating/eliminating strategies to selectively modulate immunogenicity for disease treatment. These strategies potentially exploit ROS-modulating inorganic biomaterials to harness host immunity to maximize the therapeutic potency by eliciting a favorable immune response. Inorganic biomaterial-guided in vivo ROS scavenging can exhibit several effects to: i) reduce the secretion of pro-inflammatory factors, ii) induce the phenotypic transition of macrophages from inflammatory M1 to immunosuppressive M2 phase, iii) minimize the recruitment and infiltration of immune cells. and/or iv) suppress the activation of nuclear factor kappa-B (NF-κB) pathway. Inversely, ROS-generating inorganic biomaterials have been found to be capable of: i) inducing immunogenic cell death (ICD), ii) reprograming tumor-associated macrophages from M2 to M1 phenotypes, iii) activating inflammasomes to stimulate tumor immunogenicity, and/or iv) recruiting phagocytes for antimicrobial therapy. This review provides a systematic and up-to-date overview on the progress related to ROS-nanotechnology mediated immunomodulation. We highlight how the ROS-generating/eliminating inorganic biomaterials can converge with immunomodulation and ultimately elicit an effective immune response against inflammation, autoimmune diseases, and/or cancers. We expect that contents presented in this review will be beneficial for the future advancements of ROS-based nanotechnology and its potential applications in this evolving field.

Site-Specific Biomimicry of Antioxidative Melanin Formation and Its Application for Acute Liver Injury Therapy and Imaging.

Biocompatible nano-antioxidants composed of natural molecules/materials, such as dopamine and melanin, are of great interest for diverse biomedical applications. However, the lack of understanding of the precise structure of these biomaterials and thus the actual dose of effective components impedes their advancement to translation. Herein, a strategy to mimic in situ melanin formation and explore its antioxidative applications is reported, by developing a PEGylated, phenylboronic-acid-protected L-DOPA precursor (PAD) that can self-assemble into well-defined nanoparticles (PADN). Exposure to oxidative species leads to deprotection of phenylboronic acids, transforming PADN to PEG-L-DOPA, which, similar to the biosynthetic pathway of melanin, can be oxidized and polymerized into an antioxidative melanin-like structure. With ultrahigh stability and superior antioxidative activity, the PADN shows remarkable efficacy in prevention and treatment of acute liver injury/failure. Moreover, the in situ structure transformation enables PADN to visualize damaged tissue noninvasively by photoacoustic imaging. Overall, a bioinspired antioxidant with precise structure and site-specific biological activity for theranostics of oxidative stress-related diseases is described.

Auto-fluorescent polymer nanotheranostics for self-monitoring of cancer therapy via triple-collaborative strategy.

Aberrant regulation of angiogenesis supply sufficient oxygen and nutrients to exacerbate tumor progression and metastasis. Taking this hallmark of cancer into account, reported here is a self-monitoring and triple-collaborative therapy system by auto-fluorescent polymer nanotheranostics which could be concurrently against angiogenesis and tumor cell growth by combining the benefits of anti-angiogenesis, RNA interfere and photothermal therapy (PTT). Auto-fluorescent amphiphilic polymer polyethyleneimine-polylactide (PEI-PLA) with positive charge can simultaneously load hydrophobic antiangiogenesis agent combretastatin A4 (CA4), NIR dye IR825 and absorb negatively charged heat shock protein 70 (HSP70) inhibitor (siRNA against HSP70) to construct self-monitoring nanotheranostics (NPICS). NPICS can effectively restrain the expression of HSP70 to reduce their endurance to the IR825-mediated PTT, leading to an enhanced photocytotoxicity. In a xenograft mouse tumor model, NPICS show an effect of inhibition of tumor angiogenesis and also display a highly synergistic anticancer efficacy with NIR laser irradiation. Significantly, based on its inherent auto-fluorescence, PEI-PLA not only serves as the drug carrier, but also as the self-monitor to real-time track NPICS biodistribution and tumor accumulation via fluorescence imaging. Moreover, IR825 endows NPICS could also be used as photoacoustic (PA) agents for in vivo PA imaging. This nanoplatform shows enormous potentials in cancer theranostics.

A non-conjugated polyethylenimine copolymer-based unorthodox nanoprobe for bioimaging and related mechanism exploration.

Unconventional non-conjugated photoluminescent polymers have attracted increasing attention in bioimaging application, however their nonclassical photoluminescence mechanisms remain largely unclear. Herein, an amphiphilic copolymer polyethyleneimine-poly(d,l-lactide) (PEI-PDLLA) was synthesized and the obtained PEI-PDLLA copolymer exhibited intrinsic visible blue luminescence in the solid and concentrated solution states under 365 nm UV light irradiation. Using a computational assay approach, we investigated the unconventional photoluminescence mechanism of PEI-PDLLA. The results revealed that such photoluminescence should be related to the "clustered heteroatom chromophores" formed by through-space electronic interactions of N-heteroatoms in PEI. The copolymers can function as a fluorescent nanoprobe (PEI-PDLLA NPs) via a facile nanoprecipitation method and the self-assembly mechanism of PEI-PDLLA NPs was also investigated in-depth by molecular dynamics simulation. Intriguingly, the PEI-PDLLA NPs exhibited a remarkable excitation-dependent multi-wavelength emission characteristic, which was promising in acquiring a high precision imaging effect. Moreover, in contrast with conventional organic dyes with aggregation-caused quenching (ACQ), the fluorescence intensity of the PEI-PDLLA NPs was enhanced with increasing solution concentration. Furthermore, their applications in bioimaging indicated that PEI-PDLLA NPs could be utilized as a lysosome-specific and tumor-targeted nanoprobe with excellent photostability and good biocompatibility.

Hybrid Prodrug Nanoparticles with Tumor Penetration and Programmed Drug Activation for Enhanced Chemoresistant Cancer Therapy.

Despite nanomedicine having shown great potential for reversing cancer cell resistance, the suboptimal transport across multiple biological obstacles seriously impedes its reaching targets at an efficacious level, which remains a challenging hurdle for clinical success in resistant cancer therapy. Here, a lipid-based hybrid nanoparticle was designed to efficiently deliver the therapeutics to resistant cells and treat resistant cancer in vivo. The hybrid nanoparticles (D-NPs/tetrandrine (TET)) are composed of a pH-responsive prodrug 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)-doxorubicin (DOX), an efflux inhibitor TET, and a surfactant DSPE-[methoxy (poly(ethylene glycol))-2000] (DSPE-mPEG2000), which hierarchically combatted the sequential physiological and pathological barriers of drug resistance and exhibited prolonged blood circulation, high tumor accumulation, and deep tumor parenchyma penetration. In the meantime, the programmed stepwise activation of encapsulated TET and DOX suppressed the function of resistance-related P-glycoprotein in a timely manner and facilitated the DOX sustained accommodation in tumor cells. Through systematic studies, the results show that such a nanosystem dramatically enhances drug potency and significantly overcomes the DOX resistance of breast cancer with negligible systemic toxicities. These findings provide new strategies to systemically combat chemoresistant cancers.

Mesoporous Silica Coated Polydopamine Functionalized Reduced Graphene Oxide for Synergistic Targeted Chemo-Photothermal Therapy.

The integration of different therapies into a single nanoplatform has shown great promise for synergistic tumor treatment. Herein, mesoporous silica (MS) coated polydopamine functionalized reduced graphene oxide (pRGO) further modified with hyaluronic acid (HA) (pRGO@MS-HA) has been utilized as a versatile nanoplatform for synergistic targeted chemo-photothermal therapy against cancer. A facile and green chemical method is adopted for the simultaneous reduction and noncovalent functionalization of graphene oxide (GO) by using mussel inspired dopamine (DA) to enhance biocompatibility and the photothermal effect. Then, it was coated with mesoporous silica (MS) (pRGO@MS) to enhance doxorubicin (DOX) loading and be further modified with the targeting moieties hyaluronic acid (HA). The pH-dependent and near-infrared (NIR) laser irradiation-triggered DOX release from pRGO@MS(DOX)-HA is observed, which could enhance the chemo-photothermal therapy effect. In vitro experimental results confirm that pRGO@MS(DOX)-HA exhibits good dispersibility, excellent photothermal property, remarkable tumor cell killing efficiency, and specificity to target tumor cells. In vivo antitumor experiments further demonstrated that pRGO@MS(DOX)-HA could exhibit an excellent synergistic antitumor efficacy, which is much more distinct than any monotherapy. This work presents a novel nanoplatform which could load chemotherapy drugs with high efficiency and be used as light-mediated photothermal cancer therapy agent.

Triple Redox Responsive Poly(Ethylene Glycol)-Polycaprolactone Polymeric Nanocarriers for Fine-Controlled Drug Release.

Stimuli-responsive nanocarriers with the ability to respond to tumorous heterogeneity have been extensively developed for drug delivery. However, the premature release during blood circulation and insufficient intracellular drug release are still a significant issue. Herein, three disulfide bonds are introduced into the amphiphilic poly(ethylene glycol)-polycaprolactone copolymer blocks to form triple-sensitive cleavable polymeric nanocarrier (tri-PESC NPs) to improve its sensitivity to narrow glutathione (GSH) concentration. The tri-PESC NPs keep intact during blood circulation due to the limited cleaving of triple-disulfide bonds, whereas the loaded drug is efficiently released at tumor cells with the increased concentration of GSH. In vitro studies of doxorubicin-loaded tri-PESC NPs show that the nanocarriers achieve sufficient drug release in cancerous cells and inhibit the tumor cells growth, though they only bring minimum damage to normal cells. Therefore, the tri-PESC NPs with triple-sensitive cleavable bonds hold great promise to improve the therapeutic index in cancer therapy.

Polymeric Nanoparticles as a Metolachlor Carrier: Water-Based Formulation for Hydrophobic Pesticides and Absorption by Plants.

Pesticide formulation is highly desirable for effective utilization of pesticide and environmental pollution reduction. Studies of pesticide delivery system such as microcapsules are developing prosperously. In this work, we chose polymeric nanoparticles as a pesticide delivery system and metolachlor was used as a hydrophobic pesticide model to study water-based mPEG-PLGA nanoparticle formulation. Preparation, characterization results showed that the resulting nanoparticles enhanced "water solubility" of hydrophobic metolachlor and contained no organic solvent or surfactant, which represent one of the most important sources of pesticide pollution. After the release study, absorption of Cy5-labeled nanoparticles into rice roots suggested a possible transmitting pathway of this metolachlor formulation and increased utilization of metolachlor. Furthermore, the bioassay test demonstrated that this nanoparticle showed higher effect than non-nano forms under relatively low concentrations on Oryza sativa, Digitaria sanguinalis. In addition, a simple cytotoxicity test involving metolachlor and metolachlor-loaded nanoparticles was performed, indicating toxicity reduction of the latter to the preosteoblast cell line. All of these results showed that those polymeric nanoparticles could serve as a pesticide carrier with lower environmental impact, comparable effect, and effective delivery.

Tumor Acidity-Induced Sheddable Polyethylenimine-Poly(trimethylene carbonate)/DNA/Polyethylene Glycol-2,3-Dimethylmaleicanhydride Ternary Complex for Efficient and Safe Gene Delivery.

Amphiphilic PEI derivatives/DNA complexes are widely used for DNA delivery, but they are unstable in vivo and have cytotoxicity due to the excess cationic charge. PEGylation of cationic complexes can improve sterical stability and biocompatibility. However, PEGylation significantly inhibits cellular uptake and endosomal escape. In this work, sheddable ternary complexes were developed by coating a tumor acidity-sensitive ß-carboxylic amide functionalized PEG layer on the binary complexes of amphiphilic cationic polyethylenimine-poly(trimethylene carbonate) nanoparticles/DNA (PEI-PTMC/DNA). Such sheddable ternary complexes markedly reduced their nonspecific interactions with serum protein in the bloodstream and obtained minimal cytotoxicity due to the protection of the PEG shell. At the tumor site, the PEG layer was deshielded by responding to the tumor acidic microenvironment and the positively charged complexes re-exposed that had higher affinity with negatively charged cell membranes. Meanwhile the positively charged complexes facilitated endosomal escape. Accordingly, this delivery system improved the biocompatibility of gene-loaded complexes and enhanced the gene transfection efficiency. Such PEGylated complexes with the ability to deshield the PEG layer at the target tissues hold great promise for efficient and safe gene delivery in vivo.

Transferrin conjugated poly (γ-glutamic acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolamine copolymer nanoparticles for targeting drug delivery.

Targeted drug delivery strategies have shown great potential in solving some problems of chemotherapy, such as non-selectivity and severe side effects, thus enhancing the anti-tumor efficiency of chemotherapeutic agents. In this work, we have prepared a novel nanoparticle consisted of amphiphilic poly(γ-glutamic acid-maleimide-co-L-lactide)-1,2-dipalmitoylsn-glycero-3-phosphoethanolamine (γ-PGA-MAL-PLA-DPPE) copolymer decorated with transferrin (Tf), which can specifically deliver anti-cancer drug paclitaxel (PTX) to the tumor cells for targeting chemotherapy. These nanoparticles (NPs) have preferable particle size, high encapsulation efficiency and a pH-dependent release profile. As expected, The Tf modification mediate specific targeting to nasopharyngeal carcinoma (C666-1) cells and human cervical carcinoma (Hela) cells with the transferrin receptor (TfR) overexpressed and enhance cellular uptake of the NPs, as demonstrated by flow cytometry and confocal microscopy assays. In vitro cytotoxicity studies reveal that the NPs have excellent biocompatibility, and the presence of Tf enhance the activity of PTX to the targeted cells. All these results prove that Tf modified γ-PGA-MAL-PLA-DPPE NPs could facilitate the tumor-specific therapy. Therefore, such a targeting drug delivery system provides significant advances toward cancer therapy.

[The virological response in prolonged therapy of chronic hepatitis C with low-dose peginterferon alpha-2a].

OBJECTIVE: To investigate the virological response in prolonged therapy of chronic hepatitis C (CHC) with low-dose peginterferon alpha-2a. METHODS: The 92 cases of in-patients with chronic hepatitis C in September 2004 to September 2006 were divided to three groups according the endurance of interferon. The dose of peginterferon alpha-2a was 67.5 microg, 90 microg and 180 microg per week in group A, B and C respectively. The treatment duration of peginterferon alpha-2a was 96 or 48 weeks in HCV genotype 1b and 2a in group A and B, and in the group C the duration was 48 or 24 weeks in genotype 1b and 2a patients respectively. Meanwhile, ribavirin for 900-1200 mg per day combined treated with all patients. The quantitation of serum HCV RNA were conducted to determine the rapid virological response (RVR), early virological response (EVR) and sustained virological response (SVR) respectively. RESULTS: There were no significant difference between the three groups in the rate of RVR, EVR and SVR (P > 0.05). There was a higer rate of RVR, EVR and SVR in the genotype 2a group than the genotype 1b group (P < 0.05). HCV genotype was the independent predictor (OR = 12.78, 95%, CI = 11.97-82.89, P = 0.0075) of SVR. CONCLUSION: There was a similar virological response between prolonged therapy of chronic hepatitis C with low-dose peginterferon alpha-2a and the standard dose and duration. The genotype was the independent predictors of SVR in peginterferon alpha-2a antiviral therapy of chronic hepatitis C.