No abstract

No abstract

Mesoporous silica nanoparticles (MSNs) were explored as a carrier material for the stable isotope 165 Ho and, after neutron capture, its subsequent therapeutic radionuclide, 166 Ho (half-life, 26.8 h), for use in radionuclide therapy of ovarian cancer metastasis. Methods: 165 Ho-MSNs were prepared using 165 Ho-acetylacetonate and MCM-41 silica particles, and stability was determined after irradiation in a nuclear reactor (reactor power, 1 MW; thermal neutron flux of approximately 5.5 · 10 12 neutrons/cm 2 Ás). SPECT/ CT and tissue biodistribution studies were performed after intraperitoneal administration of 166 Ho-MSNs to SKOV-3 ovarian tumor-bearing mice. Radiotherapeutic efficacy was studied by using PET/CT with 18 F-FDG to determine tumor volume and by monitoring survival. Results: The holmium-MSNs were able to withstand long irradiation times in a nuclear reactor and did not release 166 Ho after significant dilution. SPECT/CT images and tissue distribution results revealed that 166 Ho-MSNs accumulated predominantly in tumors (32.8% 6 8.1% injected dose/g after 24 h; 81% 6 7.5% injected dose/g after 1 wk) after intraperitoneal administration. PET/CT images showed reduced 18 F-FDG uptake in tumors, which correlated with a marked increase in survival after treatment with approximately 4 MBq of 166 Ho-MSNs. Conclusion: The retention of holmium in nanoparticles during irradiation and in vivo after intraperitoneal administration as well as their efficacy in extending survival in tumor-bearing mice underscores their potential as a radiotherapeutic agent for ovarian cancer metastasis.

Many travelers are interested in the usage of smartphones for their trips. This study aims in investigating the determinants of their intentions to adopt information on smartphones for travel decision making. This paper suggests a combined model to examine travelers’ intentions to use travel information on their smartphones from two standpoints: hardware using the united theory of acceptance and use of technology (UTAUT) and software using the e‐satisfaction (E‐SAT) model. The results show that four main determinants influence travelers' intentions to use travel information on smartphones for their trips: usefulness, ease of use, social influence, and satisfaction with travel websites. Copyright © 2013 John Wiley & Sons, Ltd.

Development of a successful bioresponsive drug delivery system requires exquisite engineering of materials so that they are able to respond to the signals stemming from the physiological environment. In this study, we proposed a new Pluronic® based thermogelling system containing matrix metalloproteinase-2 (MMP2) responsive peptide sequences. A novel thermosensitive multiblock copolymer comprising an MMP2-labile octapeptide (Gly-Pro-Val-Gly-Leu-Ile-Gly-Lys) was synthesized from Pluronic® triblock copolymer. The polymer was designed to form thermogel at body temperature and degrade in presence of MMP overexpressed in the tumor. The synthesized polymer was a multiblock copolymer with ~ 2.5 units of Pluronic®. The multiblock copolymer solutions exhibited a reverse thermal gelation around body temperature. The gelation temperatures of the multiblock copolymer solutions were lower than those of the corresponding Pluronic® monomer at a particular concentration. The cytotoxicity of the synthesized polymer was lower comparing to its monomer. The solubility of hydrophobic anticancer drug, paclitaxel, was enhanced in the polymer solutions via micelle formation. The synthesized polymer was preferentially degraded in presence of MMP. Paclitaxel release was dependent on the enzyme concentration. These findings suggest that the synthesized polymer has the potential as controlled drug delivery system due to its unique phase transition and bioresponsive behavior.