GALAMOST [graphics processing unit (GPU)-accelerated large-scale molecular simulation toolkit] is a molecular simulation package designed to utilize the computational power of GPUs. Besides the common features of molecular dynamics (MD) packages, it is developed specially for the studies of self-assembly, phase transition, and other properties of polymeric systems at mesoscopic scale by using some lately developed simulation techniques. To accelerate the simulations, GALAMOST contains a hybrid particle-field MD technique where particle–particle interactions are replaced by interactions of particles with density fields. Moreover, the numerical potential obtained by bottom-up coarse-graining methods can be implemented in simulations with GALAMOST. By combining these force fields and particle-density coupling method in GALAMOST, the simulations for polymers can be performed with very large system sizes over long simulation time. In addition, GALAMOST encompasses two specific models, that is, a soft anisotropic particle model and a chain-growth polymerization model, by which the hierarchical self-assembly of soft anisotropic particles and the problems related to polymerization can be studied, respectively. The optimized algorithms implemented on the GPU, package characteristics, and benchmarks of GALAMOST are reported in detail.

In the present study, we report the development of magnetic− plasmonic bilayer vesicles assembled from iron oxide−gold Janus nanoparticles (Fe 3 O 4 −Au JNPs) for reactive oxygen species (ROS) enhanced chemotherapy. The amphiphilic Fe 3 O 4 −Au JNPs were grafted with poly(ethylene glycol) (PEG) on the Au surface and ROS-generating poly(lipid hydroperoxide) (PLHP) on the Fe 3 O 4 surface, respectively, which were then assembled into vesicles containing two closely attached Fe 3 O 4 −Au NPs layers in opposite directions. The selfassembly mechanism of the bilayered vesicles was elucidated by performing a series of numerical simulations. The enhanced optical properties of the bilayered vesicles were verified by the calculated results and experimental data. The vesicles exhibited enhanced T 2 relaxivity and photoacoustic properties over single JNPs due to the interparticle magnetic dipole interaction and plasmonic coupling. In particular, the vesicles are pH responsive and disassemble into single JNPs in the acidic tumor environment, activating an intracellular biochemical reaction between the grafted PLHP and released ferrous ions (Fe 2+ ) from Fe 3 O 4 NPs, resulting in highly efficient local ROS generation and increased intracellular oxidative stress. In combination with the release of doxorubicin (DOX), the vesicles combine ROSmediated cytotoxicity and DOX-induced chemotherapy, leading to greatly improved therapeutic efficacy than monotherapies. High tumor accumulation efficiency and fast vesicle clearance from the body were also confirmed by positron emission tomography (PET) imaging of radioisotope 64 Cu-labeled vesicles.