New approaches for enhancing the photosensitivity, antibacterial activity, and controlled release behavior of non-porous silica-titania nanoplatforms

This research presents a new approach for the synthesis of inorganic nano-platforms containing >2 layers. Nano-platforms were characterized using scanning electron microscopy, X-ray diffraction, fluorescence and Fourier transform infrared spectroscopy, fluorescence microscopy, dynamic light scattering, thermogravimetric analysis, Brunauer-Emmett-Teller, etc. Since it has been reported that the maximum tolerable dose of non-porous silica nanoparticles (NPs) in in-vivo studies is higher than that of mesoporous silica, the non-porous silica was prepared. Curcumin (CUR) was trapped between the surfaces of the spherical non-porous silica and titania NPs (<100 nm) as both fluorescent and therapeutic agents, thus resulting in increased loading capacity of the non-porous silica NPs, as well as providing significant photosensitivity, antibacterial activity, and controlled release. In addition, the surface of NPs was enriched with Methyl violet-10B (MV-10B), and Rhodamine B (RhB). Silica@CUR@titania exhibited approximately 9-fold higher fluorescence intensity than silica@CUR NPs. This finding enabled us to design nano-platforms with minimum toxic effect due to low contents of RhB for bioimaging applications. The antimicrobial efficiency of nano-platforms was evaluated against P. aeruginosa, E. coli, S. typhimurium, K. pneumonia, S. epidermidis, S. aureus, B. subtilis, B. cereus, and E. faecalis. It was concluded that titania markedly lowered the minimum inhibitory concentration values (MICs) of CUR against all bacteria except B. subtilis and P. aeruginosa. Theoretical simulation was also performed to clarify the accumulation of functionalized NPs in tumor tissue.

Low noise patch-clamp current amplification by nanoparticles plasmonic-photonic coupling (analysis and modelling)

In this article, a patch-clamp low noise current amplification based on nanoparticles plasmonic radiation is analyzed. It is well-known, a very small current is flowing from different membrane channels and so, for extra processing the current amplification is necessary. It is notable that there are some problems in traditional electronic amplifier due to its noise and bandwidth problem. Because of the important role of the patch-clamp current in cancer research and especially its small amplitude, it is vital to intensify it without adding any noises. In this study, the current amplification is performed firstly: from the excitement of nanoparticles by the patch-clamp pico-ampere current and then, the effect of nanoparticles plasmonic far-field radiation on conductor's carriers, which will cause the current amplification. This relates to the plasmonic-photonic coupling and their effect on conductor carriers as the current perturbation agent. In the steady state, the current amplification can reach to 1000 times of initial level. Furthermore, we investigated the nanoparticles morphology changing effect such as size, nanoparticles inter-distance, and nanoparticles distance from the conductor on the amplifier parameters. Finally, it should note that the original aim is to use nanoparticles plasmonic engineering and their coupling to photonics for output current manipulating.

Separation by nanoparticles plasmonic resonance with low stress in microfluidics channel (analytical and design)

In this study, nanoparticles near-field plasmonic resonance is used to improve the traditional cell separation main outputs such as viability and efficiency. The live cells viability is severely depend on stresses, which are applied on cells in the microfluidics channel. Hence, for improving the cell viability, the enforced stresses inside of the structure should be declined. The major factors of the enforced stresses are related to the electric field non-uniformity, which are attributed to the hurdles and applied voltage magnitude. Therefore, in this study, a new structure is presented and thereby, the magnitude of the applied stresses on live cells is minimised which is contributed to the decreasing the non-uniformity strength of channel. It should be noted that in the new structure two arrays of nanoparticles were used to produce a short range and localised non-uniform electrical field because of their near-field plasmonic resonance. Hence, the enforced stress on the live cell severely decreased at the far-field and confined at the small section of the channel. It is due to, the near-field plasmonic amplitude is dramatically disappeared by increasing distance, hence, the cells far from the nanoparticles will be endured the low level but effective amount of the optical force.

Enhancement of tumor smart-targeting efficiency based on optical communication between signaling and receiving nanoparticles (modeling and analysis)

As far as we know, this is the first time optical communication between signaling and receiving nanoparticles has been analyzed and simulated for tumor smart-targeting.