A copper-loaded self-assembled nanoparticle for disturbing the tumor redox balance and triple anti-tumor therapy.

Both chemodynamic therapy and photodynamic therapy, based on the production of reactive oxygen (ROS), have excellent potential in cancer therapy. However, the abnormal redox homeostasis in tumor cells, especially the overexpressed glutathione (GSH) could scavenge ROS and reduce the anti-tumor efficiency. Therefore, it is essential to develop a simple and effective tumor-specific drug delivery system for modulating the tumor microenvironment (TME) and achieving synergistic therapy at the tumor site. In this study, self-assembled nanoparticles (named CDZP NPs) were developed using copper ion (Cu2+), doxorubicin (Dox), zinc phthalocyanine (ZnPc) and a trace amount of poly(2-(di-methylamino)ethylmethacrylate)-poly[(R)-3-hydroxybutyrate]-poly(2-(dimethylamino)ethylmethacrylate) (PDMAEMA-PHB-PDMAEMA) through chelation, π-π stacking and hydrophobic interaction. These triple factor-responsive (pH, laser and GSH) nanoparticles demonstrated unique advantages through the synergistic effect. Highly controllable drug release ensured its effectiveness at the tumor site, Dox-induced chemotherapy and ZnPc-mediated fluorescence (FL) imaging exhibited the distribution of nanoparticles. Meanwhile, Cu2+-mediated GSH-consumption not only reduced the intracellular ROS elimination but also produced Cu+ to catalyze hydrogen peroxide (H2O2) and generated hydroxyl radicals (˙OH), thereby enhancing the chemodynamic and photodynamic therapy. Herein, this study provides a green and relatively simple method for preparing multifunctional nanoparticles that can effectively modulate the TME and improve synergetic cancer therapy.

Conductive Antifouling Sensing Coating: A Bionic Design Inspired by Natural Cell Membrane.

Constructing antifouling coatings for biosensing interfaces is a major hurdle in driving their practical application. Inspired by the excellent antifouling properties of natural cell membranes, a conductive biomimetic antifouling interface coating is proposed, which highly mimics the excellent antifouling properties of biofilms while overcoming the low conductivity defects of conventional coatings. Polyethylene glycol-Au gel is selected as the support structure and electron transfer layer, on which phospholipids and ampholytes are applied to construct a hydration layer for antifouling. The coating maintains promisingly low adsorption in biological matrices such as whole blood, serum, and urine, and has been utilized to construct multimodal clinical assay systems that provide favorable concordance with clinical results. Thus, this conductive bio-coating breaks the last barrier of biosensors toward practical applications and possesses extremely significant application value.

Root Canal Disinfection Using Highly Effective Aggregation-Induced Emission Photosensitizer.

Root canal (RC) therapy is the primary treatment of dental-pulp and periapical diseases. The mechanical method and chemical irrigation have limitations in RC therapy. Much attention has focused on exploring more controllable and efficacious antimicrobial methods. Although the introduction of photodynamic therapy (PDT) has provided the ideas for RC debridement, the problems of low photosensitive efficiency and nonsignificant germicidal potency of traditional photosensitizers (e.g., methylene blue) have not been solved. Since the concept of "aggregation-induced emission" (AIE) was proposed, optimization of photosensitizers has been boosted considerably. Herein, an AIE photosensitizer, DPA-SCP, with a strong ability to generate singlet oxygen, is proposed for use as an antibacterial application in infected RCs. The antimicrobial activity of DPA-SCP against Enterococcus faecalis suspensions was tested. To explore the antibacterial ability of this photosensitizer against bacterial-biofilm colonization on the inner walls of RCs, we established a model of bacterial biofilm infection. PDT mediated by DPA-SCP had a significant germicidal effect on E. faecalis suspensions and 21-day biofilms in human RCs. PDT mediated by DPA-SCP could achieve efficiency equivalent to that observed using 1% NaOCl, and lead to no significant change in the dentin surface, chemical corrosion, or cytotoxicity.

Fluorescence and drug loading properties of ZnSe:Mn/ZnS-Paclitaxel/SiO2 nanocapsules templated by F127 micelles.

Hydrophobic ZnSe:Mn/ZnS core-shell fluorescence quantum dots (QDs) and anticancer drug paclitaxel (PTX) have been co-loaded into folate conjugated hybrid silica nanocapsules via F127 micelles based soft-template method in a mild aqueous environment at room temperature. The encapsulation of QDs shows a F127: QDs mass ratio dependent behavior, which impact much on the morphology and optical properties of composite nanocapsules. These as prepared composite nanocapsules also exhibit good photoluminescence stability under the temperature ranges from 19°C to 49°C. In addition, the aqueous solubility of PTX (0.1µg/mL) can be efficiently enhanced about 630 times to 62.99µg/mL, and the loaded PTX could be released during 12h sustainably. These tunable fluorescence, enhanced drug loading efficiency and sustained release behavior manifest that the hybrid nanocapsule is a promising theranostic nanoplatform for future combined fluorescence imaging and chemotherapy.

Steam explosion distinctively enhances biomass enzymatic saccharification of cotton stalks by largely reducing cellulose polymerization degree in G. barbadense and G. hirsutum.

In this study, steam explosion pretreatment was performed in cotton stalks, leading to 5-6 folds enhancements on biomass enzymatic saccharification distinctive in Gossypium barbadense and Gossypium hirsutum species. Sequential 1% H2SO4 pretreatment could further increase biomass digestibility of the steam-exploded stalks, and also cause the highest sugar-ethanol conversion rates probably by releasing less inhibitor to yeast fermentation. By comparison, extremely high concentration alkali (16% NaOH) pretreatment with raw stalks resulted in the highest hexoses yields, but it had the lowest sugar-ethanol conversion rates. Characterization of wall polymer features indicated that biomass saccharification was enhanced with steam explosion by largely reducing cellulose DP and extracting hemicelluloses. It also showed that cellulose crystallinity and arabinose substitution degree of xylans were the major factors on biomass digestibility in cotton stalks. Hence, this study has provided the insights into cell wall modification and biomass process technology in cotton stalks and beyond.