Gold Nanoclusters‐Based Nanoprobes for Simultaneous Fluorescence Imaging and Targeted Photodynamic Therapy with Superior Penetration and Retention Behavior in Tumors

Gold nanoclusters (GNCs) attract increasing attention due to their potential applications in sensing, catalysis, optoelectronics, and biomedicine. Herein, the formation of highly fluorescent glutathione (GSH)‐capped GNCs is achieved through the delicate control of the reduction kinetics and thermodynamic selection of the Au(I)–SG complexes. Furthermore, the GNCs‐based nanoprobes are developed by the covalent coupling folic acid (FA) and PEG (polyethylene glycol) on the surface of GNCs directly, followed by trapping photosensitizer (chlorin e6, Ce6) within PEG networks and attaching to the GNCs surface. The fabricated nanoprobes (Ce6@GNCs‐PEG_2K‐FA) possess a uniform particle size (hydrodynamic diameter ≈6.1 ± 1.2 nm), without affecting the yield of singlet oxygen of the trapped Ce6. In vitro studies show the enhanced cellular uptake and satisfactory photodynamic therapy (PDT) effectiveness toward MGC‐803 cells when compared with free Ce6. The biodistribution and excretion pathway studies of the nanoprobes in MGC‐803 tumor‐bearing nude mice reveal their superior penetration and retention behavior in tumors, while the preserved features of renal clearance and stealthy to reticulo‐endothelial system are mainly attributed to the small hydrodynamic diameters and the FA‐capped PEGylated ligands. The enhanced PDT efficacy and the nontoxicity to mice provide an exciting new nano‐platform with promising clinical translational potential.     

Gated Mesoporous Silica Nanoparticles Using a Double‐Role Circular Peptide for the Controlled and Target‐Preferential Release of Doxorubicin in CXCR4‐Expresing Lymphoma Cells

B‐cell non‐Hodgkin's lymphoma (B‐NHL) is the most frequent malignant lymphoid neoplasm, which has a high degree of relapse and chemoresistance. Thus, strategies to improve currently used therapies are needed. In this context, a new CXCR4‐targeted delivery system is described using mesoporous silica nanoparticles (MSNs) that are loaded with doxorubicin and capped with a derivative of the T22 peptide (P). This design makes full use of the great affinity of the T22 peptide to CXCR4 receptor, which is overexpressed in lymphoma cells. The peptide is able to guide the gated nanoparticle to B‐NHL cells to facilitate MSNs uptake via the CXCR4 receptor. The endocyted P‐capped MSNs are also opened by endosomal proteolytic enzymes to allow intracellular doxorubicin delivery.     

Electro-optical and dielectric study of multi-walled carbon nanotube doped polymer dispersed liquid crystal films

The self-organising property of nematic liquid crystals (LCs) was used to align multi-walled carbon nanotubes (MWCNT) dispersed in them. MWCNT not only well integrate in the matrix but also, even at very low concentration, have a detectable effect on the LC properties that can be very attractive for display applications. In the present work, MWCNT were doped (0–0.5% wt/wt) in two different types of LCs. These MWCNT doped polymer dispersed LC (CPDLC) films were studied comprehensively using fundamental techniques. Polarising optical microscope (POM) and scanning electron microscope (SEM) techniques used for morphological study reveal that the LC droplet size remains unchanged with increase in MWCNT concentration. The electro-optical (EO) study performed by increasing voltage in steps of 10 V up to 100 V at an optimised frequency of 200 Hz and at temperature 25°C shows that the low MWCNT concentration films show good optical response than the higher one. The dielectric behaviour of CPDLC films in the frequency range 20 Hz to 20 MHz was investigated using precision impedance analyser. The obtained data were modelled with Debye and Cole-Cole methods to calculate relaxation time and distribution parameter (α). The zero value of α indicates Debye type relaxation processes.     

酞菁在光动力治疗中的应用

光动力治疗因具有低毒、副作用小、抗癌广谱、高选择性等优势, 正吸引着人们越来越多的关注。提高光敏剂的选择性和光毒性已经成为研究的热点。本文简单介绍了光敏剂的发展历程, 并对酞菁类第三代光动力治疗光敏剂的最新研究进展进行了论述。     

酞菁在光动力治疗中的应用

光动力治疗因具有低毒、副作用小、抗癌广谱、高选择性等优势,正吸引着人们越来越多的关注。提高光敏剂的选择性和光毒性已经成为研究的热点。本文简单介绍了光敏剂的发展历程,并对酞菁类第三代光动力治疗光敏剂的最新研究进展进行了论述。