Silicon quantum dots delivered phthalocyanine for fluorescence guided photodynamic therapy of tumor

Imaging-guided cancer therapy provides a simultaneous tumor imaging and treatment, which helps to eliminate the excessive toxicity to the healthy tissues. For this purpose, multifunctional probes capable of both imaging and curing are needed. In this work, we synthesize water-soluble silicon quantum dots(Si QDs) smaller than 5 nm. Such Si QDs are used for delivering the hydrophobic drug phthalocyanine(Pc). The as-prepared Si/Pc nanocomposite particles show efficient transmembrane delivery into cells and feasible biocompatibility. Moreover, these composite particles emit dualchannel fluorescence signals even after cellular internalization and demonstrate robust photostability in the Si channel.More interestingly, the Si/Pc composite particles show efficient photodynamic therapy effects against tumors both in vitro and in vivo.     

Modulated Collective Motions and Condensation of Bacteria

Bacteria can spontaneously develop collective motions by aligning their motions in dense systems. Here we show that bacteria can also respond collectively to an alternating electrical field and form dynamic clusters oscillating at the same frequency of the field. As the dynamic clusters go beyond a critical size, they split into smaller ones spontaneously. The critical size for splitting depends on the frequency of electric field and the concentration of bacteria. We show that, instead of their ...     

流感病毒和冠状病毒的细胞表面结合与内化

病毒是一种在活细胞内寄生并以复制方式增殖的非细胞型生物.不同病毒侵入细胞的方式不同,但大都需要通过结合至细胞表面特定的受体蛋白或脂质结构来实现细胞内化,从而启动入侵程序和感染宿主细胞.因此揭示病毒结合和内化侵入细胞的具体过程及机制有助于从源头上开发靶向药物或疫苗.本文以流感病毒和冠状病毒为例,首先介绍了流感病毒的结构,其与细胞膜上特定种类蛋白或脂质结构的结合方式,其完成细胞内吞的途径及诱导其内化的细胞因子种类,以及侵入细胞后的作用过程,继而对冠状病毒尤其针对目前仍在全球范围内肆意传播的新型冠状病毒(SARS-Co V-2),扼要阐述了其结构特点、与细胞受体血管紧张素转化酶ACE2的结合及实现细胞内化的研究进展.