Enhanced inactivation of Escherichia coli by ultrasound combined with peracetic acid during water disinfection.

Peracetic acid (PAA) is a desirable disinfectant for municipal wastewater because of its potent disinfection performance and limited toxic by-products. This study explored the efficiency and mechanism of Escherichia coli inactivation by PAA combined with ultrasound simultaneously (ultrasound + PAA) or (ultrasound → PAA) sequentially. The result showed that 60 kHz ultrasound combined with PAA sequentially (60 kHz → PAA) had excellent inactivation performance on E. coli, up to 4.69-log10. The result also showed that the increase of pH and humic acid concentration in solution significantly reduced the inactivation efficiency of 60 kHz → PAA treatment. We also observed that the increase of temperature was beneficial to the disinfection, while anions (Cl-; HCO3-) had little effect. With 60 kHz → PAA, the PAA and the synergism between PAA and ultrasound played major contribution to the inactivation, which we assumed might be due to both the diffusion of PAA into the cells and the damage to the cytomembrane by ultrasound, as evidenced through the laser confocal microscopy (LSCM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The inactivation mechanism involved the destruction of cell membrane and loss of intracellular material. Empirically, 60 kHz → PAA was found to be effective for the inactivation of E. coli in actual wastewater, and the regrowth potential of E. coli treated by 60 kHz → PAA was significantly lower than that treated only by PAA.

Functionalized polymer modified buried interface for enhanced efficiency and stability of perovskite solar cells.

Although great progress has been made in perovskite solar cells (PCSs), further development of PCSs is hindered by a large number of defects, nonradiative recombination, and mysterious stresses. Here, we propose a new interfacial strategy by introducing a new polymer material named povidone-iodine (PV-I) as a buffer layer. A series of studies indicate that the introduced buffer layer can form a strong chemical interaction with SnO2 and the perovskite, which can not only passivate the defects of the two functional layers but also strengthen the interfacial connection. The reduction of film defects and the enhancement of interface connection are beneficial to the extraction and transport of the carrier. In addition, the introduction of a buffer layer releases the interfacial stress. Ultimately, we achieved attractive efficiency (22.02%, 0.1 cm2) and considerable long-term stability (after aging 500 h, the target device still retains 81% of its original PCE). The excellent performance of the device indicates that this strategy can be used as an effective control method for perovskite solar cells to facilitate their commercialization.

In-situ micro-Raman study of SnSe single crystals under atmosphere: Effect of laser power and temperature.

Single crystal of tin selenide (SnSe) was studied by micro-Raman spectroscopy under atmosphere conditions. The effect of varying the incident laser power on the sample up to 2 mW was analyzed. The Raman spectra showed that the number of all vibrational modes have not decreased or increased, but all peaks red-shifted and softened obviously as the laser power increased to the threshold value. The temperature-dependent micro-Raman study of the single crystal was carried out for illustrating thermal effect due to the high incident laser power. A new SnSe2 phase appeared at high temperature without vacuum and become the dominant phase at the surface of the crystal gradually because of oxidation. Detecting few amounts of SnSe2 crystals on the surface of single crystal shows the high sensitivity of Raman spectroscopy. High resolution transmission electron microscopy (HRTEM) was also used to confirm that the newly generated SnSe2 phase is precipitated by SnSe under high temperature oxidation conditions. To study the Raman spectra of low thermal conductivity materials under high temperature and non-vacuum conditions, lower incident laser power should be used to avoid the influence of additional thermal effects.

Furin-instructed aggregated gold nanoparticles for re-educating tumor associated macrophages and overcoming breast cancer chemoresistance.

Insufficient drug accumulation and chemoresistance remain two major challenges in cancer chemotherapy. Herein, we designed a furin-responsive aggregated nanoplatform loaded with doxorubicin (DOX) and hydroxychloroquine (HCQ) (AuNPs-D&H-R&C) to combine chemotherapy, autophagy inhibition and macrophage polarization. AuNPs-D&H-R&C could passively target breast tumor via enhanced permeability and retention (EPR) effect after systemic administration and further aggregate together triggered by furin overexpressed in breast cancer. The in situ aggregations hindered the back-flow of NPs to the bloodstream and exocytosis of tumor cells, leading to enhanced drug accumulation within tumors. Moreover, upon exposure to acidic pH in the endosomes/lysosomes, HCQ was efficiently released and it inhibited autophagy and thus restored the sensitivity of tumor cell to DOX. Meanwhile, autophagy inhibition could reprogram tumor-promoting M2-like TAMs to anti-tumor M1 phenotype, exerting a synergistic effect in overcoming chemoresistance. In vitro studies demonstrated the superiority of furin-triggered aggregated AuNPs delivery system in enhancing drug accumulation in breast tumor, compared with PEGlyated AuNPs. The co-delivery of DOX and HCQ showed much improved chemotherapeutic efficiency to chemoresistant MCF-7/ADR breast tumor, in large part due to macrophage polarization. In conclusion, we developed a stimulus-responsive delivery system and proposed a potential combination strategy to overcome chemoresistance in cancer chemotherapy.

D-T7 Peptide-Modified PEGylated Bilirubin Nanoparticles Loaded with Cediranib and Paclitaxel for Antiangiogenesis and Chemotherapy of Glioma.

The blood-brain tumor barrier (BTB) and blood-brain barrier (BBB) have always been the major barriers in glioma therapy. In this report, we proposed D-T7 peptide-modified nanoparticles actively targeted glioma by overcoming the BBB and BTB to improve the antiglioma efficacy. Glioma-targeting experiments showed that the penetration effect of the D-T7 peptide-modified nanoparticles was 7.89-fold higher than that of unmodified nanoparticles. Furthermore, cediranib (CD) and paclitaxel (PTX) were used for the combination of the antiangiogenesis and chemotherapy for glioma. PEGylated bilirubin nanoparticles (BRNPs) were selected as a suitable drug delivery system (CD&PTX@TBRBPs) owing to the antioxidant, anti-inflammatory, and reactive oxygen species-responsive ability. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and apoptosis assays showed that CD&PTX@TBRBPs had the highest cytotoxicity and the median survival time of the CD&PTX@TBRNP group was 3.31-fold and 1.23-fold longer than that of the saline and CD&PTX@BRNP groups, respectively. All the results showed that we constructed a novel and accessible peptide-modified dual drug carrier with an enhanced antiglioma effect.

Coadministration of iRGD with Multistage Responsive Nanoparticles Enhanced Tumor Targeting and Penetration Abilities for Breast Cancer Therapy.

Limited tumor targeting and poor penetration of nanoparticles are two major obstacles to improving the outcome of tumor therapy. Herein, coadministration of tumor-homing peptide iRGD and multistage-responsive penetrating nanoparticles for the treatment of breast cancer are reported. This multistage-responsive nanoparticle, IDDHN, was comprised of an NO donor-modified hyaluronic acid (HN) shell and a small-sized dendrimer, namely, dendri-graft-l-lysine conjugated with doxorubicin and indocyanine (IDD). The results showed that IDDHN could be degraded rapidly from about 330 nm to a smaller size that was in a size range of 35 to 150 nm (most at 35-60 nm) after hyaluronidase (HAase) incubation for 4 h; in vitro cellular uptake demonstrated that iRGD could mediate more endocytosis of IDDHN into 4T1 cells, which was attributed to the overexpression of αvß3 integrin receptor. Multicellular spheroids penetration results showed synergistically enhanced deeper distribution of IDDHN into tumors, with the presence of iRGD, HAase incubation, and NO release upon laser irradiation. In vivo imaging indicated that coadministration with iRGD markedly enhanced the tumor targeting and penetration abilities of IDDHN. Surprisingly, coadministration of IDDHN with iRGD plus 808 nm laser irradiation nearly suppressed all tumor growth. These results systematically revealed the excellent potential of coadministration of iRGD with multistage-responsive nanoparticles for enhancing drug delivery efficiency and overcoming the 4T1 breast cancer.

Enzyme-triggered size shrink and laser-enhanced NO release nanoparticles for deep tumor penetration and combination therapy.

Chemotherapy remains restricted by poor drug delivery efficacy due to the heterogenous nature of tumor. Herein, we presented a novel nanoparticle that could not only response to the tumor microenvironment but also modulate it for deep tumor penetration and combination therapy. The intelligent nanoparticle (IDDHN) was engineered by hyaluronidase (HAase)-triggered size shrinkable hyaluronic acid shells, which were modified with NIR laser sensitive nitric oxide donor (HN), small-sized dendrimeric prodrug (IDD) of doxorubicin (DOX) as chemotherapy agent and indocyanine green (ICG) as photothermal agent into a single nanoparticle. IDDHN displayed synergistic deep penetration both in vitro and in vivo, owing to the enzymatically degradable HN shell mediated by HAase and laser-enhanced NO release triggered deep penetration upon strong hyperthermia effect of ICG under the NIR laser irradiation. The therapeutic effect of IDDHN was verified in 4T1 xenograft tumor model, and IDDHN showed a much better antitumor efficiency with few side effects upon NIR laser irradiation. Therefore, the valid of this study might provide a novel tactic for engineering nanoparticles both response to and modulate the tumor microenvironment for improving penetration and heterogeneity distribution of therapeutic agents in tumor.

Multidimensional Theranostics for Tumor Fluorescence Imaging, Photoacoustic Imaging and Photothermal Treatment Based on Manganese Doped Carbon Dots.

Multidimensional theranostics have received a lot of attention because of their improved diagnostic accuracy and therapeutic diversity. In this study, we developed a kind of manganese doped nigrosine originated carbon dots (Mn-NCDs), with the average particle size of approximate 3 nm and the long emission wavelength of 653 nm. In vitro experiment demonstrated that Mn-NCDs could be well internalized by 4T1 cells, and the temperature of Mn-NCDs solution could rapidly rise from 23.1 °C to more than 50 °C when exposed to NIR laser, thus it could generate enough hyperthermia to efficiently destroy 4T1 cells. Furthermore, the in vivo fluorescent and photoacoustic imaging studies highlighted the applicability of Mn-NCDs in dual-mode tumor diagnosis. The prepared Mn-NCDs with long emission wavelength and photothermal anti-cancer effect exhibited great potential for dual-mode imaging and treatment of triple negative breast cancer.