Hypocrellin B doped and pH-responsive silica nanoparticles for photodynamic therapy

pH-responsive ¹O₂ photosensitizing systems may serve as selective photodynamic therapy (PDT) agents by targeting the acidic interstitial fluid of many kinds of tumors. In this work, a natural and clinically used photosensitizer (Hypocrellin B, HB) and a pH indicator (Bromocresol Purple, BCP) were co-encapsulated in organically modified silica nanoparticles. BCP successfully regulated the ¹O₂ generation efficiency of HB through the “inner filter” effect, which shows much stronger ¹O₂ generation ability in an acidic than in a basic environment. In vitro experiments also demonstrated that HB-doped nanoparticles are effective in killing tumor cells by PDT.

     

Two-Dimensional Photonic Band-Gap Defect Modes with Deformed Lattice

A numerical study of the defect modes in two-dimensional photonic crystals with deformed triangular lattice is presented by using the supercell method and the finite-difference time-domain method. We find the stretch or shrink of the lattice can bring the change not only on the frequencies of the defect modes but also on their magnetic field distributions. We obtain the separation of the doubly degenerate dipole modes with the change of the lattice and find that both the stretch and the shrink of the lattice can make the dipole modes separate large enough to realize the single-mode emission. These results may be advantageous to the manufacture of photonic crystal lasers and provide a new way to realize the single-mode operation in photonic crystal lasers.     

HI-6人体血清白蛋白纳米粒的制备及其对梭曼中毒小鼠脑AChE重活化作用评价

迅速恢复中毒乙酰胆碱酯酶(acetylcholinesterase,AChE)活性是神经性毒剂中毒救治最关键的环节.血脑屏障的存在限制了具有重活化作用的抗毒药物以有效治疗剂量进入中枢.本研究以已知重活化作用最强的重活化剂酰胺磷定(HI-6)为目标药物,通过去溶剂化法制备了人体血清白蛋白纳米粒,通过静电作用将HI-6分子装载在纳米粒表面,合成装载HI-6的人体血清白蛋白纳米粒;在斑马鱼及神经性毒剂梭曼染毒小鼠上,对药物穿透血脑屏障能力及中枢中毒AChE重活化作用进行了评价.结果表明,装载HI-6人体血清白蛋白纳米粒在物理表征上符合纳米药物基本特征;相对于自由HI-6,HI-6人体血清白蛋白纳米粒能够透过血脑屏障,并将中枢中毒AChE活性提升2倍以上,表明人体血清白蛋白纳米粒成功携带HI-6分子进入中枢.本文建立了一种无毒、高效、小尺寸中枢靶向性纳米粒的制备方法,基于该方法制备的纳米重活化剂,在脑内可有效释放目标药物并迅速发挥解毒作用.     

三重态-三重态湮灭上转换的研究进展

三重态-三重态湮灭（TTA）上转换具有所需激发光能量低（地表太阳光光强即可激发）、上转换量子效率高、吸光能力强、激发发射波长可调等优点,在光电器件与光反应等领域具有重要的潜在应用价值,近年来受到了广泛关注．本文介绍了TTA上转换产生的机理与上转换量子效率的测定方法,着重对TTA上转换三重态光敏剂的分子设计原则及目前该类化合物的结构类型进行了综述,介绍了聚合物中的固态上转换现象及目前TTA上转换在光解水制氢、太阳能电池与细胞成像等方面的最新应用研究进展．