Latest ArticlesRadiotherapy is one of the most important clinical cancer treatments, which works mainly by delivering a prescribed radiation dose to the tumor tissues. However, high doses of radiation may also lead many irreversible damages to the surrounding normal tissues. Thereby, how to effectively reduce these sideeffects has been a significant factor in influencing cancer therapeutic effect. In this work, we synthesized the hollow PtPd nanocubes with high-index facets, and investigated the radiation protection capability in vitro and in vivo. Our results showed the PtPd nanocrystals can decrease the ROS level and improve the survival rate of radiated cells. Meanwhile, survival rate of radiated mice can significantly increase from 0 to 30% after PtPd treatment. Consequently, the enzyme and ROS level in radiated mice can be recovered.
Nonviral vectors have been attracting more attention for several advantages in gene delivery and the development of nonviral gene carriers with high delivery efficiency and low cytotoxicity has long been a key project. Starburst polyamidoamine dendrimers are a class of synthetic polymers with unique structural and physical characteristics. However, when they are used as gene carrier, the gene transfection efficiency is not satisfactory. Herein, a novel thioketal-core polyamidoamine dendrimer (i.e., ROS-PAMAM) was synthesized and characterized. Compared to ethylenediamine-core dendrimers or widely used cationic polymers of polyetherimide, ROS-PAMAM showed lower cytotoxicity. Moreover, ROS-PAMAM demonstrated reactive oxygen species responsive characteristics, which can facilitate the release of siRNA in the tumor microenvironment. In vitro gene transfection experiments based on A549 cells confirmed that siRNA/ROS-PAMAM exhibits high gene transfection efficiency. It is concluded that ROS-PAMAM shows great potential as a generalizable vehicle for gene therapy applications.
Both of carbon dioxide (CO2) and near-infrared (NIR) light as triggers for non-invasive remotely control are attracting wide attentions due to their good biocompatibility and easy operation. Here, CO2/NIR light dual controlled nanoparticles are proposed to remotely regulate the unzipping of dsDNA by using imidazole functionalized conjugated polymer nanoparticles (imidazole-CPNs). The dsDNA successfully coats on the shell of imidazole-CPNs to form imidazole-CPNs/dsDNA assembly due to intensively electrostatic interaction triggered by CO2. Furthermore, the unzipping process of dsDNA is remotely controlled by NIR light based on the photothermal effect, and it can be readily monitored by the fluorescence intensity of ethidium bromide (EB) and CD spectra of dsDNA. Thus, dual stimulation responsive imidazole-CPNs effectively control dsDNA unzipping under CO2 stimulus and NIR light, promising a new direction in the biological applications of DNA, such as the treatments of diseases caused by gene duplication abnormality.
It is urgent to find a technology accurately to better diagnose and treat to brain tumor. Eu-doped Gd2O3 nanorods (Eu-Gd2O3 NRs) with paramagnetic and fluorescent properties were conjugated with doxorubicin (Dox) and chlorotoxin (CTX) via PEGylation, hydrazone bond and sulfur bond (named as CTXNRs-Dox), and these NRs could release more Dox in lower pH environment. The results of cell experiments indicated that CTX-NRs-Dox had obvious targeting and toxic effects on U251 cells, as well as good fluorescence imaging behavior. The orthotopic glioma-transplanted mice models were constructed via the intracranial injection of glioma cells (U87MG). The result of experiments after the tail-vein injection of the prepared NRs suggested that CTX-NRs-Dox could target to brain tumors via the long-time blood circulation, leading to their obvious contrast enhancement of MR imaging of the intracranial tumor and their significant inhibitory effect on the growth and metastasis of brain tumors. A mechanism of synergistic effect of CTX-NRs-Dox on targeting and inhabiting the brain tumor was proposed. Our research suggested that CTX-NRs-Dox had potential application prospect in the detection and treatment of glioma.
As a kind of stimuli-responsive materials, the disulfide-containing material has received a tremendous amount of interest. A novel functional disulfide-containing waterborne polyurethane (DS-WPU) nanoemulsion was prepared via a one-step in situ phase inverse emulsification technique and its reducing-responsive property was investigated using dithiothreitol as the reductant. Results showed that the DS-WPU nanoemulsion had a uniform particle size in nanoscale and a good film-forming characteristic, and the DS-WPU latex film exhibited great responsiveness along with a self-assembled behavior in the reducing environment to form WPU emulsion again, including a long-to-short process of the polymer chains.
Highly luminescent colloidal nanocrystals have wide applications in bioimaging and various optoelectronic devices. Herein we report a facile and mild procedure by combining S2- treatment and binary ligand passivation, which can efficiently enhance the luminescent property of CdSe nanocrystals at room temperature. The photoluminescence quantum yield of as-treated CdSe nanocrystals exhibits drastic enhancement (e.g., 188 times for CdSe nanorods) after this dual-passivation treatment. The methodology proposed here can be applied to various CdSe nanocrystals, regardless of their sizes, shapes, and crystal structures.
The synthesis and stimuli-responsiveness of a diphenyl cyclopropenone (DPCP)-centered poly(methyl acrylate) (PMA) are presented. DPCP-centered PMA could release carbon monoxide (CO) upon UV light in a switched on-and-off manner. The CO-releasing process can be reported by the variations in photoluminescence spectra. In addition, DPCP moiety covalently embedded in the crosslinked polyurethane could also release CO under UV light. Of special, DPCP-centered PMA in solution was selectively dissociated at the phenol ester bond under the ultrasound, and a force-induced hydrolyzation reaction was revealed by D2O exchanging 1H NMR spectra. The kinetic study reveals that small quantity of water could enhance the chain scission rate. This work provides a DPCP-centered polymer for sitespecific CO-releasing and chain dissociation.
In order to optimize mass transportation and exchange, nature creates hierarchically porous networks which are composed of multi-level branches. Although bottom-up templating methods have succeeded in fabrication of these kinds of hierarchically porous networks, the templates have to be assembled/ packed in advance, therefore, driving the fabrication process too complex. In this report, we presented that the hierarchically porous networks could be fabricated through migration of templates, which was similar to formation of rivers. During thermal pyrolysis of Prussian blue cages, the in situly generated iron oxides nanoparticles diffused and aggregated together to grow larger, and eventually moved outside from the porous carbons. The moving routes of the iron oxides became hierarchical channels in the obtained carbon cages. By using the porous carbon cages as electrode for Na-ion battery, a pseudocapacitor-type ion storage was investigated.