Insurer green finance under regulatory cap-and-trade mechanism associated with green/polluting production during a war.

The cap-and-trade mechanism affects firms' production and operation decisions and carbon emissions, making them move towards environmental sustainability. This article develops a contingent claims model to examine the impact of the regulatory cap-and-trade mechanism on the green finance strategy of an insurer during a war. Participating in the cap-and-trade scheme of the insurer that funds the borrowing firms also implicitly affects firm production and carbon emissions. The results show that increasing the green loans decreases the interest margin of the insurer but helps policyholder protection. The insurer is reluctant to provide green loans for the green borrowing firm and thus retards sustainable development. A stringent regulatory cap of the cap-and-trade mechanism raises the insurer's interest margin but hurts policyholder protection. From the perspective of the insurer's profit, regulatory cap efficiently derives insurer lending toward sustainability through borrowing-firm cleaner production. An increased war impacting the polluting borrowing firm increases the insurer's interest margin but harms policyholder protection, affecting insurance stability adversely. This research enriches related literature and knowledge concerning insurer green finance practices indirectly associated with cleaner production. The research also highlights the significance of the regulatory cap-and-trade mechanism that reflects cleaner production in affecting insurer performance during a war.

Catalpol Protects Against Spinal Cord Injury in Mice Through Regulating MicroRNA-142-Mediated HMGB1/TLR4/NF-κB Signaling Pathway.

Background: Spinal cord injury (SCI) is a devastating condition that leads to paralysis, disability and even death in severe cases. Inflammation, apoptosis and oxidative stress in neurons are key pathogenic processes in SCI. Catalpol (CTP), an iridoid glycoside extracted from Rehmannia glutinosa, has many pharmacological activities, such as anti-inflammatory, anti-oxidative and anti-apoptotic properties. Purpose: Here, we investigated whether CTP could exert neuroprotective effects against SCI, and explored the underlying mechanism involved. Methods: SCI was induced by a weight-drop device and treated with CTP (10 mg and 60 mg/kg). Then the locomotor function of SCI mice was evaluated by the BBB scores, spinal cord edema was measured by the wet/dry weight method, oxidative stress markers and inflammatory factors were detected by commercial kits and neuronal death was measured by TUNEL staining. Moreover, the microRNA expression profile in spinal cords from mice following SCI was analyzed using miRNA microarray. In addition, reactive oxygen species (ROS) generation, inflammatory response and cell apoptosis were detected in murine microglia BV2 cells under oxygen-glucose deprivation (OGD) and CTPtreatment. Results: Our data showed that CTP treatment could improve the functional recovery, as well as suppress the apoptosis, alleviate inflammatory and oxidative response in SCI mice. In addition, CTP was found to be up-regulated miR-142 and the protective effects of CTP on apoptosis, inflammatory and oxidative response may relate to its regulation of HMGB1/TLR4/NF-κB pathway through miR-142. Conclusion: Our findings suggest that CTP may protect the spinal cord from SCI by suppression of apoptosis, oxidative stress and inflammatory response via miR-142/HMGB1/TLR4/NF-κB pathway.

Characterization and hepatoprotective effect of polysaccharides from Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou sarcocarp.

The polysaccharides from Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H. F. Chou sarcocarp (PWJS) is evaluated for the chemical composition, antioxidant activity and hepatoprotective effect. The characteristics of PWJS were determined by FT-IR spectral and HPLC analysis. The antioxidant activity was investigated using in vitro systems. An in vivo study of PWJS against CCl4 induced liver injury was also conducted. HPLC analysis showed that PWJS is an acidic heteropolysaccharide, rich in glucose (38.59%), arabinose (23.16%), galacturonic acid (17.64%) and galactose (10.44%). PWJS displayed strong antioxidant activity in vitro. In the in vivo study, PWJS treatment lowered the serum levels of ALT and AST in CCl4-intoxicated mice. Additionally, levels of antioxidant enzymes (SOD and CAT) and GSH were elevated in liver damage mice by PWJS intervention, while content of MDA was lessened. Meanwhile, PWJS reverses the suppression of Nrf2 nuclear translocation, and increases the protein expression of HO-1, GSTα and NQO1 in liver damage mice. Hematoxylin-eosin staining showed that the condition of liver damage was mitigated. This study demonstrates that PWJS reverses hepatotoxicity in CCl4-intoxicated mice through the mechanisms of antioxidant activity, as well as an augmentation of the Nrf2 pathway in liver tissue.

A strategy to improve serum-tolerant transfection activity of polycation vectors by surface hydroxylation.

The aim of this contribution is to develop a universal method to promote the serum-tolerant capability of polycation-based gene delivery system. A "hydroxylation camouflage" strategy was put forward by coating the polycation vectors with hydroxyl-enriched "skin". Branched polyethyleneimine (PEI) was herein used as the polycation model and modified via the catalyst-free aminolysis reaction with 5-ethyl-5-(hydroxymethyl)-1,3-dioxan-2-oxo (EHDO). PEI-g-EHDO, PEI and alkylated PEI derivative termed as PEI-g-DPA were comparatively explored with respect to the transfection efficiency in the serum-free and serum-conditioned medium. The resultant data indicate that the serum-tolerant capability largely depended on the surface composition and substitution degree. In addition to the reduced surface charge, the introduced function caused by hydroxyl coating is believed to play a crucial role for the improved properties of PEI-g-EHDOs. The EHDO modification can effectively inhibit the adsorption of BSA proteins onto polyplexes surface. And the polyplexes stability was remarkably enhanced in the presence of DNase and heparin after EHDO modification. Note that the transfection activity of PEI-g-EHDO(34.5%) in the serum-conditioned medium was even higher than that without serum addition. In contrast, serum addition led to appreciable reduction in the transfection efficiency mediated by PEI and PEI-g-DPAs. Specifically, as far as the transfection activity in the presence of serum is concerned, PEI-g-EHDO could be up to 30-fold higher than unmodified PEI25k. PEI-g-EHDO(34.5%) displayed little to no hemolytic effect and high cell-biocompatibility with nearly no cytotoxicity detected in 293T cells and HeLa cells. Taking into account the high biocompatibility and serum-tolerant transfection activity, PEI-g-EHDO(34.5%) holds great potential for the use as efficient gene vector. More importantly, it is expected that such "hydroxylation camouflage" strategy may be universally applicable for a majority of existing polycation vectors.

Poly(ß-amino amine) cross-linked PEIs as highly efficient gene vectors.

To increase the release of DNA into the cytoplasm and further improve transgene expression of nucleic acid novel polymeric gene carriers were prepared which would be biodegradable under the reducing conditions in the cytoplasm. Disulfide-containing poly(ß-amino amine)s were first synthesized and then used to cross-link low molecular weight polyethyleneimine (1800 Da) through Michael addition to obtain SS-PBAA-PEIs as the final gene carriers. The physicochemical characteristics of SS-PBAA-PEI/DNA complexes were characterized. In vitro transfection mediated by the SS-PBAA-PEIs under serum conditions was carried out. Cell uptake of the gene delivery systems was observed by confocal laser scanning microscopy. The results of the physicochemical characterisation demonstrated that the SS-PBAA-PEIs could efficiently condense DNA. In vitro transfection under serum conditions showed that SS-PBAA-PEIs had comparable or even higher transfection efficiencies than 25 kDa PEI. And SS-PBAA-PEIs showed much lower cytotoxicity compared with 25 kDa PEI. In summary, the SS-PBAA-PEIs possess great potential as non-viral gene vectors and exhibit high transfection efficiency under serum conditions.

Fabrication of lactobionic-loaded chitosan microcapsules as potential drug carriers targeting the liver.

This paper demonstrates a general approach for fabrication of lactobionic chitosan microcapsules using layer-by-layer assembly via click chemistry. Chitosan was selectively modified with either azide (CHI-Az) or alkyne (CHI-Alk) groups. The growth of the CHI-Az/CHI-Alk click multilayer was studied experimentally by multilayer assembly on planar supports. Linear buildup of the film was observed. The chitosan click capsules were also analyzed with confocal laser scanning microscopy and transmission electron microscopy. Capsules were found to have regular spherical shapes. In addition, (CHI-Az/CHI-Alk)-coated particles were modified with fluorescein isothiocyanate to ensure that the particles can be easily post-functionalized. Finally, lactobionic acid was conjugated onto the (CHI-Az/CHI-Alk)-coated particles and the lactobionic particles exhibited hepatoma cell (HepG2) targeting behavior.

PEGylated PEI-based biodegradable polymers as non-viral gene vectors.

Novel functional biodegradable gene vectors, poly(L-succinimide)-g-polyethylenimines-g-poly(ethylene glycol) (PSI-g-PEI-g-PEGs) were synthesized by conjugating methoxy poly(ethylene glycol) (mPEG, M(w)=750 Da) to PEI segments (M(w)=800 Da) of PSI-g-PEI. The physicochemical properties of PSI-g-PEI-g-PEGs, including buffering capability, pDNA binding ability, cytotoxicity, zeta potential and the particle size of polymer/pDNA complexes, were explored. The influence of PEGylation was discussed based on a comparative study of PSI-g-PEI-g-PEGs, PSI-g-PEI and PEI25k (M(w)=25 kDa). SEM images revealed that PSI-g-PEI-g-PEG/pDNA particles have a regular shape with the diameter ranging from 70 to 170 nm. PEGylation could suppress the aggregation occurrence between complexes, resulting in a reduction of the polymer/pDNA complex size. PSI-g-PEI-g-PEGs exhibited remarkably lower cytotoxicity compared to PSI-g-PEI and PEI25k. In 293T and HeLa cells, the obtained PSI-g-PEI-g-PEGs showed very high transfection efficiency compared to PEI25k. Fluorescent confocal microscopy demonstrated that PSI-g-PEI-g-PEGs could effectively transport pGL-3 plasmids into the nuclei of HeLa cells. Taking into account the continued high transfection efficacy and decreased toxicity after PEG modification, PSI-g-PEI-g-PEGs show great potential as the non-viral vectors for gene transfection.

Self-Assembled Micelles Based on PEG-Polypeptide Hybrid Copolymers for Drug Delivery.

A series of amphiphilic poly(L-leucine)-block-poly(ethylene glycol)-block-poly(L-leucine) (PLL-PEG-PLL) hybrid triblock copolymers have been synthesized. All the blocks in this system have good biocompatibility and low toxicity. The PLL-PEG-PLL copolymers could self-assemble into micelles with PLL blocks as the hydrophobic core and PEG blocks as the hydrophilic shell, which were characterized by FT-IR, (1) H NMR, and transmission electron microscopy analysis. The critical micellar concentration of the copolymer was 95.0 mg · L(-1) . The circular dichroism spectrum shows that the PLL segments adopt a unique α-helical conformation, which is found to play an important role in controlling the drug release rate. The drug release could be effectively sustained by encapsulation in the micelles. The copolymers may have potential applications in drug delivery.

[Effect of active site of Xiangsha Liujunzitang on behavior and injury of hippocampal neurons in depression model mice].

OBJECTIVE: To observe the effect of the active site of Xiangshia Liujunzitang on behavior, injury of hippocampal neurons and Ca2+ ion in hippocampal synaptic in the depression model mice. METHOD: Sixty male Kunming mice were randomly divided into 5 group, the control group, the model group and the active site of Xiangshia Liujunzitang groups (400, 600, 800 mg x kg(-1) body weight). The model was established by separation and chronic unpredictable mild stimulation. The increased weight and crossing scores, rearing scores were measured by open-field and sweet water consumption of mice. Cone cell and configuration of neuron in CA1, CA3 region of hippocampus were observed by Nissl. The concentration of Hippocampal synaptic Ca2+ was detected by fluorimetry. RESULT: Comparing with the mice of control, the increased weight was slowed (P < 0.001), the scores of rearing and crossing were decreased (P < 0.001), sweet water consumption were decreased, too. Numbers of cone cells in CA3 region of hippocampus were decreased obviously (P < 0.001), and Ca2+ ion in hippocampal synaptic was increased obviously. Comparing with the mice of model, the active site of Xiangshia Liujunzitang could increase the increased weight on the 14 th and 21 st day obviously. The active site of Xiangshia Liujunzitang could increase the scores of crossing obviously (P < 0.05), with no dose-effect relationship. The active site of Xiangshia Liujunzitang (800 mg x kg(-1)) could increase the scores of rearing obviously (P < 0.001); The active site of Xiangshia Liujunzitang (400, 600, 800 mg x kg(-1)) could increase sweet water consumption obviously (P < 0.01, P < 0.01, P < 0.001); The active site of Xiangshia Liujunzitang (600, 800 mg x kg(-1)) could increase numbers of cone cell in CA3 region of hippocampus obviously (P < 0.001); The active site of Xiangshia Liujunzitang (600, 800 mg x kg(-1)) could decreased Ca2+ in hippocampal synaptic with dose-effect relationship (P < 0.01, P < 0.001). CONCLUSION: The active site of Xiangshia Liujunzitang can improve all the symptoms of the depression model mice and protect the injury of hippocampal neurons in the depression model mice. The possible mechanism of action is to restrict Ca2+ ion overfreight.

Peptide-functionalized thermo-sensitive hydrogels for sustained drug delivery.

In this study, a KRGDKK (Lys-Arg-Gly-Asp-Lys-Lys) peptide with a RGD sequence is utilized as a functional group to synthesize a novel thermo-sensitive hydrogel. The KRGDKK peptide prepared by a solid phase synthesis approach is coupled to the ends of a poly[(epsilon-caprolactone)-co-lactide]-poly(ethylene glycol)-poly[(epsilon-caprolactone)-co-lactide] (PCLA-PEG-PCLA) triblock copolymer to obtain peptide-PCLA-PEG-PCLA-peptide. The self-assembly behavior of both PCLA-PEG-PCLA and peptide-PCLA-PEG-PCLA-peptide copolymers in aqueous solution is investigated, and hydrogels prepared from PCLA-PEG-PCLA and peptide-PCLA-PEG-PCLA-peptide are also prepared. An in vitro cell viability study demonstrated that the peptide-PCLA-PEG-PCLA-peptide hydrogels do not exhibit an apparent cytotoxicity, which suggests that the hydrogels have promising potential as injectable drug-delivery systems. Furthermore, compared with the PCLA-PEG-PCLA hydrogels, the peptide-PCLA-PEG-PCLA-peptide hydrogels display improved mechanical properties because of hydrogen bonding between the amino groups of KRGDKK. An in vitro drug release study showed that the peptide-PCLA-PEG-PCLA-peptide hydrogels exhibit outstanding controlled release properties and the release of the drug could be sustained for more than a month without initial burst.

Convenient preparation of biodegradable PEI-containing polymers as non-viral vectors for gene transfection.

Poly(L-succinimide)-graft-polyethylenimines (PSPs) were prepared as non-viral vectors for gene transfection. Branched polyethylenimine (Mw= 800, PEI800) was grafted to poly(L-succinimide) (PSI) in a one-step reaction with no catalyst. Gel retardation assay showed that the mobility of PSP/pDNA complexes was completely retarded at the low N/P ratio of 0.42. In vitro transfection experiments showed that, at N/P ratio of 0.84, PSPs can reach the highest transfection level with ten-fold enhancement in 293T cells and five-fold enhancement in HeLa cells as compared with PEI25k (Mw= 25,000). Fluorescent confocal microscopy showed that pGL-3 plasmids condensed by PSPs could be effectively transported into the nuclei of HeLa cells. Significantly reduced cytotoxicity of polymers was observed towards 293T and HeLa cells, with the 50% inhibition concentration of PSPs being almost four times higher than that of PEI25k.

Facile fabrication of diblock methoxy poly(ethylene glycol)-poly(tetramethylene carbonate) and its self-assembled micelles as drug carriers.

AB type diblock methoxy poly(ethylene glycol)-b-poly(tetramethylene carbonate) (mPEG-PTeMC) copolymers were designed for the first time and used as carriers for the sustained release of the hydrophobic drug ibuprofen. In this paper, we developed a facile ring-opening polymerization (ROP) method to prepare mPEG-PTeMC copolymers under the catalysis of Novozym-435 lipase. Attractively, the polymerization has been successfully performed at 30 degrees C, close to room temperature. The data show that the copolymer compositions agree well with the feed ratio of TeMC to mPEG, indicating the controllable feature of the polymerization. The copolymer structures were characterized by (1)H NMR, IR, SEC, and DSC measurements. mPEG-PTeMC exhibits no apparent in vitro cytotoxicity toward human embryonic kidney transformed 293T cells. Those amphiphilic copolymers can readily self-assemble into nanosized micelles (about 150 nm) in aqueous solution. Their critical micelle concentrations are in the range of (1.6-9.3) x 10(-7) mol/L, determined by fluorescence spectroscopy. The micelles present high stability in PBS solution, with no obvious change in micelle diameters over 5 days. Ibuprofen can be loaded effectively in mPEG-PTeMC micelles, and its sustained release behavior is observed. Transmission electron microscopy shows that the well-dispersed spherical micelles are around 25 nm in diameter, while the diameter is 30 nm after loading ibuprofen. The release rate increases when the chain length of the PTeMC block decreases. These properties show that the micelles self-assembled from mPEG-PTeMC copolymers would have great potential as carriers for the effective encapsulation as well as sustained release of hydrophobic drugs.