Activatable theranostic prodrug scaffold with tunable drug release rate for sequential photodynamic and chemotherapy

Glutathione(GSH)-activated prodrugs are promising for overcoming the limitations of conventional anti-tumor drugs.However,current GSH-responsive disulfide groups exhibit unregulated reactivity,making it impossible to precisely control the drug release rate.We herein report a series of GSH-responsive prodrugs with a“three-in-one”molecular design by integrating a fluorescence report unit,stimuliresponsive unit and chemodrug into one scaffold with tunable aromatic nucleophilic substitution(SNAr)reactivity.The drug release rate of these prodrugs is tailored by modification of substituent groups with different electron-withdrawing or-donating abilities on the BODIPY core.Furthermore,the prodrugs self-assemble in water to form nanoparticles that serve as photosensitizers to produce reactive oxygen species upon irradiation for photodynamic therapy(PDT).The PDT process also increases the concentration of GSH in cells,further promoting the release of drugs for chemotherapy.This strategy provides a powerful platform for sequential photodynamic and chemotherapy with tunable drug release rates and synergistic therapeutic effects.

Integrated Development Path of Red Tourism and Rural Revitalization:A Case Study of Li Xiongcai's Hometown in Guangdong

With the increasing attention of the state to the protection and development and utilization of red tourism resources,a series of policy documents have been promulgated and implemented one after another,laying a solid policy and environmental foundation for the integrated development of red tourism and rural revitalization.In this context,this study takes"Li Xiongcai's hometown"in Kengwei Village,Baitu Town,Gaoyao District,Zhaoqing City,Guangdong Province,as a case study,adopts the questionnaire survey method to explore the current situation of the integration and development of red tourism and rural revitalization in five dimensions,namely,industry,culture,talent,ecology and organization,and summarizes the problems in the process of the integration and development of red tourism and rural revitalization and proposes a targeted optimization path to promote the development of red tourism.Targeted optimization paths are proposed to promote the high-quality development of red tourism in Li Xiongcai's hometown,to support the comprehensive revitalization of the countryside,and to provide model cases for other regions in the integration of red tourism and rural revitalization.

Exploring the Integration of Digital Intelligence into the Whole Process of Ideological and Political Education of Political Economy Course in Colleges and Universities

The fusion of digital technology and education has ushered in an era of intelligent educational environment.The course of Political Economy in colleges and universities not only imparts economic knowledge and cultivates financial quotient,but also bears the important task of improving students ideological and moral character.It is worth exploring how to effectively use digital technology to integrate ideological and political education into political economy more accurately.On the basis of building the ideological and political education system of political economy course,this paper explores the practical path of ideological and political education in the era of digital intelligence from three aspects:"before class","during class"and"after class".

热塑性淀粉的制备及在聚乳酸复合材料中的应用

通过糠基缩水甘油醚(FGE)的化学接枝改性,成功制得具有优异熔融加工性能的热塑性淀粉。红外光谱和核磁共振氢谱分析表明,通过马来酸酐的桥接作用,FGE成功接枝到淀粉分子上。X射线衍射分析发现,FGE的接枝能有效破坏淀粉的晶体结构,从而赋予FGE接枝淀粉(FGE-g-St)优异的热塑性加工性能。动态接触角测试发现,FGE-g-St的接触角从原淀粉(N-St)的30°左右提高至65°左右,表现出极其优异的疏水性能,从而显著改善了FGE-g-St与聚乳酸的界面相容性。相对于PLA/N-St复合材料,PLA/FGE-g-St复合材料的拉伸强度、弯曲强度和断裂伸长率均得到显著提高,这得益于其优异的界面相容性。

Orange-emitting bimetallic nanoclusters combined with cyan-emitting Fe@TAOH as white light-emitting materials

White-light-emitting diodes(WLEDs)possess many merits,such as high efficiency and stability.Developing cost-effective,environmentally friendly,high-performance luminophores to achieve high-quality,full-spectrum,white lighting is of great importance to the construction and progress of WLEDs.In this work,solid-state,highly luminescent orange-emitting nanoclusters(MgCl_(2)-Lys-Ag/Au NCs)were prepared via the salt-induced precipitation of Lys-Ag/Au NCs from solution,which showed a high absolute quantum yield of 44.5%.A cyan-emitting metal-organic framework(MOF)-like nanomaterial(named Fe@TAOH)was also prepared by the self-assembly of the coordination compound of Fe^(3+)and TAOH acted upon by H_(3)PO_(4) via H-bonding andπ-πstacking interactions,which showed an emission peak at 485 nm and an absolute quantum yield of 21.7%.The potential application of the two facile-synthesis,low toxicity,and highly luminescent materials in WLEDs was investigated.The WLEDs was constructed by coating powdered Fe@TAOH and MgCl_(2)-Lys-Ag/Au NCs samples on commercial GaN LED chip with 365 nm emissions,and it exhibited acceptable white light characteristics with a CIE color coordinates and a color rendering index(CRI)of(0.28,0.34)and 79.6,respectively,implying good prospects in the field of WLEDs.

In situ synthesis of red fluorescent gold nanoclusters with enzyme-like activity for oxidative stress amplification in chemodynamic therapy

Chemodynamic therapy (CDT) has attracted tremendous interest in cancer therapy because it is independent of oxygen and photoirradiation. However, the therapeutic efficacy of CDT is restricted by insufficient H_(2)O_(2) levels in tumor cells. Herein, employing endogenous GSH as a template and cationic polymeric chitosan (CS) as crosslinker and stabilizer exhibiting easy cell uptake, red luminescent gold nanoclusters (denoted CS-GSH@AuNCs) were successfully synthesized in HeLa cells. The in situ synthesized CS-GSH@AuNCs exhibited both superoxidase dismutase (SOD) and peroxidase (POD)-like activity, which could promote the production of H_(2)O_(2) from superoxide anion radicals (O_(2)^(·-)) and then ^(·)OH. The combination of GSH elimination and H_(2)O_(2) elevation boosted the generation of ^(·)OH, which could trigger cancer cell apoptosis and death. The enzyme-like activity of CS-GSH@AuNCs could be effectively activated under acidic conditions, and showed a high killing effect on tumor cells but minimal toxicity to normal cells. The developed GSH consumption and ^(·)OH promotion theranostic platform is an innovative route for enhanced CDT by the amplification of oxidative stress.

Visualizing nitric oxide-dependent HIF-1 activity under hypoxia with a lipid droplet-targeting fluorescent probe

Evaluating the correlation between hypoxia inducible factor 1(HIF-1) and nitric oxide(NO) generated under hypoxia is of great significance. In this work, we developed a fluorescent probe for the monitor of HIF-1 activity influenced by NO under hypoxia in hepatoma cells with dual-targeting for hepatocyte and lipid droplet(LD). The probe shows excellent selectivity to NO and high sensitivity with 6000-fold fluorescence enhancement. Live cell imaging experiments revealed the probe’s capability of imaging exogenous and endogenous NO with specific in LDs of Hep G2 cells. For cells under hypoxia, HIF-1 induced LD level is observed to correlate with NO level. This work provides the in-situ visualization of NO-dependent HIF-1 upregulation through LD accumulation.