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.

     

电子束的绝热展开

考虑空间电荷效应,用数值方法模拟计算了电子束绝热展开过程.当初始磁感应强度与最终磁感应强度之比为K时,电子束横向温度由初始值Ti降低Ti/K.研究了不同能量、不同流强的电子束达到预期的绝热展开倍数所需的最低磁感应强度.