Sclerotinia rot of Zephyranthes candida caused by Sclerotinia sclerotiorum and Sclerotinia minor.

Sclerotinia rot is a serious disease that occurs on Zephyranthes candida. A thorough understanding of the pathogenic fungal species and understanding the biological characteristics are important for controlling sclerotinia. Fungal strains were isolated from the diseased leaves of Z. candida through tissue isolation. Koch's hypothesis screened pathogenic strains by pathogenicity of healthy leaves, including re-isolation and identification. A multigene phylogenetic tree was constructed by extracting genomic DNA from pathogenic strains and measuring the nucleotide sequences at four sites, including the internal transcribed spacer (ITS), RNA polymerase II second largest subunit (RPB2), glyceraldehyde-3-phosphate dehydrogenase (G3PDH), and heat shock protein 60 (HSP60). Morphological characteristics of the fungal structures were evaluated through microscopic analysis. The growth of pathogens was observed and recorded under different pH, different temperatures, different carbon sources and different nitrogen sources to clarify their biological characteristics. Representative strains D7, D13, X4, and X15 infected Z. candida and caused sclerotinia rot. At the beginning of the culture, white flocculent fungal hyphae appeared on the potato dextrose agar (PDA) medium, and black spherical to irregular-shaped sclerotia appeared at the edge of the colony after 7 days. The diameter of the sclerotia was 2.4-8.6 mm and 0.4-0.9 mm, respectively. One sclerotium was able to germinate from 1 to 5 apothecia. Ascus were cylindrical or spindle-shaped, with a size of 110.0-120.0 × 9.2-11.6 µm. One ascus contained eight colorless, oval ascospores, with a size of 8.4-12.0 × 4.5-5.5 µm. Based on the phylogenetic tree constructed with the gene sequences for ITS, G3PDH, HSP60, and RPB2, D7 and D13 shared 99% homology with sclerotinia sclerotiorum, whereas X4 and X15 shared 99% homology with sclerotinia minor. S. sclerotiorum growth was more suitable when the culture temperature was 15°C-25°C, pH 5.0, carbon source was maltose and nitrogen source was yeast powder. S. minor growth was more suitable when the culture temperature was 15°C, pH 5.0, the carbon source was glucose, and the nitrogen source was yeast powder. The results identified the pathogens as S. sclerotiorum and S. minor. To the best of our knowledge, this is the first report of S. sclerotiorum and S. minor causing sclerotinia rot on Z. candida. We herein aimed to identify the causal agent of sclerotinia rot of Z. candida in China based on morphological characteristics, molecular identification, and pathogenicity tests. Performed the experiments on the biological characteristics, to understand the law of disease occurrence. We also evaluated methods for the effective control of this disease. Our findings provide support for further studies on the pathogenesis mechanism of sclerotinia rot.

Acceptor Engineering Produces Ultrafast Nonradiative Decay in NIR-II Aza-BODIPY Nanoparticles for Efficient Osteosarcoma Photothermal Therapy via Concurrent Apoptosis and Pyroptosis.

Small-molecule photothermal agents (PTAs) with intense second near-infrared (NIR-II, 1,000 to 1,700 nm) absorption and high photothermal conversion efficiencies (PCEs) are promising candidates for treating deep-seated tumors such as osteosarcoma. To date, the development of small-molecule NIR-II PTAs has largely relied on fabricating donor-acceptor-donor (D-A-D/D') structures and limited success has been achieved. Herein, through acceptor engineering, a donor-acceptor-acceptor (D-A-A')-structured NIR-II aza-boron-dipyrromethene (aza-BODIPY) PTA (SW8) was readily developed for the 1,064-nm laser-mediated phototheranostic treatment of osteosarcoma. Changing the donor groups to acceptor groups produced remarkable red-shifts of absorption maximums from first near-infrared (NIR-I) regions (~808 nm) to NIR-II ones (~1,064 nm) for aza-BODIPYs (SW1 to SW8). Furthermore, SW8 self-assembled into nanoparticles (SW8@NPs) with intense NIR-II absorption and an ultrahigh PCE (75%, 1,064 nm). This ultrahigh PCE primarily originated from an additional nonradiative decay pathway, which showed a 100-fold enhanced decay rate compared to that shown by conventional pathways such as internal conversion and vibrational relaxation. Eventually, SW8@NPs performed highly efficient 1,064-nm laser-mediated NIR-II photothermal therapy of osteosarcoma via concurrent apoptosis and pyroptosis. This work not only illustrates a remote approach for treating deep-seated tumors with high spatiotemporal control but also provides a new strategy for building high-performance small-molecule NIR-II PTAs.

Biodegradable silica nanocapsules enable efficient nuclear-targeted delivery of native proteins for cancer therapy.

Cell nucleus is the desired subcellular organelle of many therapeutic drugs. Although numerous nanomaterial-based methods have been developed which could facilitate nuclear-targeted delivery of small-molecule drugs, few are known to be capable of delivering exogenous native proteins. Herein, we report a convenient and highly robust approach for effective nuclear-targeted delivery of native proteins/antibodies by using biodegradable silica nanocapsules (BSNPs) that were surface-modified with different nuclear localization signals (NLS) peptides. We found that, upon gaining entry to mammalian cells via endocytosis, such nanocapsules (protein@BSNP-NLS) could effectively escape from endolysosomal vesicles with the assistance of an endosomolytic peptide (i.e., L17E), accumulate in cell nuclei and release the encapsulated protein cargo with biological activities. Cloaked with HeLa cell membrane, DNase@BSNP-NLS/L17E-M (with L17E encapsulated) homologously delivered functional proteins to cancer cell nuclei in tumor-xenografted mice. In vitro and in vivo anti-tumor properties, such as long blood circulation time and effective tumor growth inhibition, indicate that the nuclear-targeted cell-membrane-cloaked BSNPs (DNase@BSNP-NLS/L17E-M) platform is a promising therapeutic approach to nuclear related diseases.

Porous Silicon Nanocarriers with Stimulus-Cleavable Linkers for Effective Cancer Therapy.

Porous silicon nanoparticles (pSiNPs) are widely utilized as drug carriers due to their excellent biocompatibility, large surface area, and versatile surface chemistry. However, the dispersion in pore size and biodegradability of pSiNPs arguably have hindered the application of pSiNPs for controlled drug release. Here, a step-changing solution to this problem is described involving the design, synthesis, and application of three different linker-drug conjugates comprising anticancer drug doxorubicin (DOX) and different stimulus-cleavable linkers (SCLs) including the photocleavable linker (ortho-nitrobenzyl), pH-cleavable linker (hydrazone), and enzyme-cleavable linker (ß-glucuronide). These SCL-DOX conjugates are covalently attached to the surface of pSiNP via copper (I)-catalyzed alkyne-azide cycloaddition (CuAAC, i.e., click reaction) to afford pSiNP-SCL-DOXs. The mass loading of the covalent conjugation approach for pSiNP-SCL-DOX reaches over 250 µg of DOX per mg of pSiNPs, which is notably twice the mass loading achieved by noncovalent loading. Moreover, the covalent conjugation between SCL-DOX and pSiNPs endows the pSiNPs with excellent stability and highly controlled release behavior. When tested in both in vitro and in vivo tumor models, the pSiNP-SCL-DOXs induces excellent tumor growth inhibition.

Nonmetallic SERS-based immunosensor byintegrating MoS2 nanoflower and nanosheet towards the direct serum detection of carbohydrate antigen 19-9.

Recently, nonmetallic substrates have stimulated great interest in surface-enhanced Raman scattering (SERS)-based immunoassay owing to their good uniformity, stability, and biocompatibility. In this context, a novel nonmetallic SERS-based immunoassay mediated by two-dimensional molybdenum disulfide (MoS2) was delivered for the sensitive and specific monitoring of carbohydrate antigen 19-9 (CA19-9). The effective enrichment of molecules on the large active surfaces of MoS2 as well as potential 532-nm laser-induced charge transfer resonances between them engendered desirable enhancement factor values at the level of 105. Intriguingly, a sandwich immunocomplex combined MoS2 nanoflower and nanosheet exhibited not only a wide linear range from 5 × 10-4 to 1 × 102 IU·mL-1 but also a limit of detection as low as 3.43 × 10-4 IU·mL-1 towards CA19-9. More meaningful, the analytical result for clinical patient serum sample was basically compared with the conventional chemiluminescent immunoassay. Such a novel nonmetallic SERS-based immunosensor with desirable biocompatibility and sensitivity is promising for clinical diagnosis.

Activation of WNT7b autocrine eases metastasis of colorectal cancer via epithelial to mesenchymal transition and predicts poor prognosis.

BACKGROUND: Aberrant activation of the Wnt/ß-catenin signaling pathway is one of the most frequent abnormalities in human cancer, including colorectal cancer (CRC). Previous studies revealed pivotal functions of WNT family members in colorectal cancer, as well as their prognostic values. Nevertheless, the prognostic role and mechanisms underlying WNT7b in colorectal cancer development remains unclear. METHODS: In this study, WNT7b expression was measured by immunohistochemical staining of 100 cases of surgically resected human colorectal cancerous tissues as well as matched adjacent normal tissues constructed as tissue microarrays. In vitro studies, we attempted to substantiate the WNT7b expressional pattern previously found in immunohistochemistry staining. We used the colorectal cancer cell-line HCT116 and normal colorectal cell-line FHC for immunofluorescence staining and nuclear/cytoplasmic separated western blotting. We measured epithelial-mesenchymal transition (EMT) markers and migration capacity of HCT116 in the context of WNT7b knocked-down using short interfering RNA. Finally, clinical and prognostic values of WNT7b activation levels were examined. RESULTS: WNT7b was expressed in the nucleus in adjacent normal tissues. In CRC tissues, nuclear expression of WNT7b was similar; however, membrane and cytoplasmic expression was strikingly enhanced. Consistently, in vitro analysis confirmed the same expression pattern of WNT7b. Compared with FHC cells, HCT116 cells displayed higher levels of WNT7b membrane and cytoplasmic enrichment, as well as higher migration capacity with a sensitized EMT process. Either partial knockdown of WNT7b or blockade of the Wnt/ß-catenin signaling pathway reversed EMT process and inhibited the migration of HCT116 cells. Finally, elevated secretion levels of WNT7b were significantly associated with lymphatic and remote metastasis and predicted worse prognosis in the CRC cohort. CONCLUSION: In summary, we demonstrated that the activation of WNT7b autocrine probably contributes to CRC metastasis by triggering EMT process through the Wnt/ß-catenin signaling pathway. High levels of WNT7b autocrine secretion predicts poor outcome in patients with CRC. This molecule is a promising candidate for clinical CRC treatments.

Immunoassay of Tumor Markers Based on Graphene Surface-Enhanced Raman Spectroscopy.

With a unique chemical enhancement capability, graphene oxide is exceptionally suitable to serve as an alternative surface-enhanced Raman scattering (SERS) substrate, which is usually defined as GERS. However, such a GERS matrix with both promising uniformity and molecule enrichment ability has not been applied in the quantitative detection of tumor markers. Herein, an ultrasensitive and specific immunoassay of carcinoembryonic antigens mediated by the GERS matrix was demonstrated. With the assistance of Au NRs as immunoprobes, a reliable limit of detection as low as 3.01 pg/mL was finally achieved because of the collective effect of chemical and electromagnetic enhancements. Meanwhile, a calibration curve with a high R2 value of 0.996 was obtained in the range from 1 µg/mL to 10 pg/mL. These results exhibit that the GERS matrix has a great promise for participating in immunoassay, which may pave a potential avenue for the real utilization of the SERS technique in clinical biomedicine.