Ion Capture and Release Ability of Glass Ionomer Cement Containing Nanoporous Silica Particles with Different Pore and Particle Size.

This study prepared glass ionomer cement (GIC) containing nanoporous silica (NPS) (GIC-NPS) at 5 wt% concentrations using 3 types of NPS with different pore and particle sizes and evaluated the differences in their cationic ion capture/release abilities and mechanical properties. The cationic water-soluble dye was used as cationic ion. The test GIC-NPS complexes captured dyes by immersion in 1 wt% dye solutions. All the GIC-NPS complexes released dyes for 28 d, and the amount of dye released from the complexes increased with decreasing pore size; however, the particle size of NPS did not affect the amount of dye released. Additionally, GIC-NPS was able to recharge the dye, and the amount of released the dye by the complexes after recharge was almost identical to the amount released on the first charge. Although not significantly different, the compressive strength of GIC-NPS was slightly greater than that of GIC without NPS regardless of the type of NPS. These results suggest that the degree of capture and release of cationic molecules, such as drugs, can be controlled by optimizing the pore size of NPS without sacrificing its mechanical strength when its content is 5 wt%.

Expansion sequencing: Spatially precise in situ transcriptomics in intact biological systems.

Methods for highly multiplexed RNA imaging are limited in spatial resolution and thus in their ability to localize transcripts to nanoscale and subcellular compartments. We adapt expansion microscopy, which physically expands biological specimens, for long-read untargeted and targeted in situ RNA sequencing. We applied untargeted expansion sequencing (ExSeq) to the mouse brain, which yielded the readout of thousands of genes, including splice variants. Targeted ExSeq yielded nanoscale-resolution maps of RNAs throughout dendrites and spines in the neurons of the mouse hippocampus, revealing patterns across multiple cell types, layer-specific cell types across the mouse visual cortex, and the organization and position-dependent states of tumor and immune cells in a human metastatic breast cancer biopsy. Thus, ExSeq enables highly multiplexed mapping of RNAs from nanoscale to system scale.

Size- and Morphology-Controlled Preparation of Surface-Modified Water-Dispersible Fullerene Nanoparticles for Bioapplications.

In this study, we investigated water-dispersible surface modification for size- and shape-controlled fullerene nanoparticles (C60P) based on a condensation reaction with di-amino alkane. This modification provided for water dispersibility of C60P and the capability for secondary modification as well. The resultant C60P particles have several useful physical properties: water-dispersibility for ease of injection; fluorescence for detection and quantification; and a characteristic morphology to assist identification. These properties will widely extend the applications of these particles, especially into the biological fields of bioimaging and drug delivery.

Electric Charge Dependence of Controlled Dye-Release Behavior in Glass Ionomer Cement Containing Nano-Porous Silica Particles.

We investigated in controlled dye-release behavior of nanosized silica particles containing nanocavities (Nanoporous silica, NPS). To determine this, NPS were mixed with glass ionomer cement (GIC), which is a medical material used as a matrix. The dye-release behavior was observed using a UV-visible spectrometer. After cationic dye was charged into GIC pellet containing NPS, the pellet could gradually release cationic dye for up to two weeks. To understand the dependence of electric charge on the dye-release behavior, three types of dyes with different charge were also investigated. Dyes having a neutral or negative electric charge were quickly released from the pellet within a couple of days. These results suggest that the nanocavities present in NPS can selectively bind cationic dyes and allow for their gradual release. This result reveals the excellent sustained dye-release property of NPS.