Mutual Benefit between Cu(II) and Polydopamine for Improving Photothermal-Chemodynamic Therapy.

Combination therapy has attracted extensive interest in alleviating the shortcomings of monotherapy and enhancing the treatment efficacy. In this work, hollow mesoporous silica nanoparticles (HMSNs) play the role of nanocarriers in the delivery of Cu(II)-doped polydopamine (PDA), termed as HMSNs@PDA-Cu, for synergistic therapy. PDA acts as a traditional photothermal agent to realize photothermal treatment (PTT). Chemodynamic therapy (CDT) is realized by the reaction of Cu(II) with intracellular glutathione (GSH), and subsequently, the generated Cu(I) reacts with H2O2 to produce toxic hydroxyl radical (•OH) through a Fenton-like reaction. The photothermal performance of PDA is improved after its coordination with Cu(II). On the other hand, PDA exhibits superoxide dismutase (SOD)-mimicking activity. PDA converts O2•- to H2O2 and improves the production of H2O2, which promotes the therapeutic effect of CDT. Moreover, the high temperature caused by PTT further enhances the yield of •OH for CDT. This nanotheranostic platform perfectly applied to the tumor depletion of mice, presenting great potential for cancer metastasis therapy in vitro and in vivo.

Flexible and Stretchable Capacitive Sensors with Different Microstructures.

Recently, sensors that can imitate human skin have received extensive attention. Capacitive sensors have a simple structure, low loss, no temperature drift, and other excellent properties, and can be applied in the fields of robotics, human-machine interactions, medical care, and health monitoring. Polymer matrices are commonly employed in flexible capacitive sensors because of their high flexibility. However, their volume is almost unchanged when pressure is applied, and they are inherently viscoelastic. These shortcomings severely lead to high hysteresis and limit the improvement in sensitivity. Therefore, considerable efforts have been applied to improve the sensing performance by designing different microstructures of materials. Herein, two types of sensors based on the applied forces are discussed, including pressure sensors and strain sensors. Currently, five types of microstructures are commonly used in pressure sensors, while four are used in strain sensors. The advantages, disadvantages, and practical values of the different structures are systematically elaborated. Finally, future perspectives of microstructures for capacitive sensors are discussed, with the aim of providing a guide for designing advanced flexible and stretchable capacitive sensors via ingenious human-made microstructures.

Functional morphology of the mouthparts of lady beetle Coccinella transversoguttata (Coccinellidae, Coleoptera), with reference to their feeding mechanism.

The lady beetle Coccinella transversoguttata is an important biocontrol agent of aphids. As the main the feeding apparatus, mouthparts play essential roles in feeding process, and the morphological variation of mouthparts is correlated with variation in food source and feeding behavior. To better understand the feeding behavior of C. transversoguttata, we studied the functional morphology of mouthparts, with special attention to the fine morphology of each part of mouthpart and various kinds of sensilla. The mouthpart of C. transversoguttata is typical mandibulate type that composed of labrum, mandible, maxillae, labium, and hypopharynx. Detailed descriptions were given about the fine morphology of each part, and various types of sensilla were identified and classified. In total, two types of sensilla chaetica, four types of sensilla basiconica, two types of sensilla styloconica, two types of sensilla placodea, and one type of cuticular pore were identified according to their length, morphology and distribution. Specially, the putative function of each part of mouthpart as well as each kind of sensilla and their coordinative mechanisms in feeding process were discussed. These results would lay a solid foundation for understanding the feeding mechanism of lady beetles.

Glutathione triggered degradation of polydopamine to facilitate controlled drug release for synergic combinational cancer treatment.

Here we report a novel mechanism for triggering drug release in the polydopamine (PDA)-coated magnetic CuCo2S4 core-shell nanostructure by glutathione (GSH) triggered degradation of PDA for release. In the design, we used PDA coated CuCo2S4 as the nanocarrier with polyethylene glycol and folic acid targeting molecules to ensure the safe delivery of doxorubicin (DOX) to cancer cells. In addition, the controlled release could be enforced by taking advantage of the pH sensitivity of PDA to tumor acidic environments. The targeting and treatment of HeLa cancer cells were very effective and the killing was more efficient at higher levels of GSH. Furthermore, the designed system not only could be used for drug delivery but also could combine photothermal therapy with chemotherapy in a synergetic way. Plus, the system could be used for magnetic resonance imaging (MRI), which is beneficial for imaging-guided treatment.