Neural stem cells (NSCs) reside in anatomically confined niches, where three-dimensional (3D) geometry and interstitial fluid (ISF) flow collectively regulate NSC behavior. However, in vitro platforms that simultaneously recapitulate size-controlled 3D architecture, ISF-like dynamics, and nanoscale therapeutic delivery remain limited. Here, we present a 3D printing-based platform with multi-sized microwells, termed the Neural-Inspired Culture for a Hydrodynamic Environment (NICHE)-chip, which incorporates an osmosis-driven flow system to generate ISF-like flow. The NICHE-chip enabled stable formation of uniform human neural stem cell (hNSC) neurospheres across defined microwell sizes. Under ISF-like flow, hNSC neurospheres showed enhanced viability, reduced apoptosis, and increased self-renewal and differentiation marker expression, particularly in 100 μm microwells. ISF-like flow also promoted laminin-rich extracellular matrix (ECM) deposition and cell–cell interactions, suggesting niche-like remodeling of the 3D microenvironment. In the ISF-integrated 100 μm neurosphere model, amyloid-β (Aβ) was introduced to establish an Alzheimer’s disease (AD)-like neurotoxicity model, which was then used to evaluate nanoparticle-mediated neurotrophic factor delivery using brain-derived neurotrophic factor (BDNF)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles. BDNF-loaded PLGA nanoparticles (BDNF-NPs) enabled sustained BDNF delivery, attenuated Aβ-induced neuronal marker loss, and counter-regulated a subset of Aβ-induced transcriptional alterations associated with neuroprotection. Overall, the NICHE-chip provides an ISF-integrated 3D neurosphere culture platform for NSC niche modeling, AD-like neurotoxicity assessment, and nanoscale neurotrophic factor delivery.
Copper sulfides typically favor formate production in CO2 electrolysis, yet their behavior under membrane electrode assembly (MEA) conditions remains largely uncharted. In this study, CuxS/Cu electrodes with tunable morphologies, including spheres, films, polygons, and cubes, were synthesized, and the surface sulfur content was systematically tuned through electrodeposition followed by controlled sulfidation. Performance evaluation in MEA systems reveals that sulfidation markedly enhances C2H4 selectivity and partial current density (PCD). For spherical Cu electrodes, sulfidation to a S/Cu surface ratio of 0.33 resulted in a 1.76-fold increase in C2H4 PCD, from 58.2 to 102.5 mA/cm2 at 3.2 V. In situ Raman spectroscopy suggests that sulfur coordination stabilizes bridge-bonded CO and promotes the formation of the CH2CHO intermediate, which is consistent with the enhanced C2H4 activity. Density functional theory calculations reveal that Cu-rich sulfide surfaces, including Cu2S and Cu31S16, stabilize *OCCO intermediates, suggesting a thermodynamically favorable C–C coupling reaction pathway through synergistic Cu–S coordination. These findings identify surface sulfur incorporation as a structural motif that actively promotes CO dimerization and enhances C2H4 selectivity under MEA conditions.
Safe and Sustainable by Design (SSbD) is emerging as a transformative framework for integrating safety and sustainability with functionality in nanotechnology. This review provides a unified perspective on SSbD, bridging its scientific foundations, global policy developments, and industrial implementation. We highlight how advances in mechanistic understanding of nanomaterial–biological interactions enable earlier and more predictive safety assessment, supporting informed material design. At the policy level, evolving regulatory and governance approaches across regions are shaping the integration of sustainability and safety requirements. From an industrial perspective, SSbD is driving innovation in material substitution, process optimization, and lifecycle-oriented design. Despite this progress, challenges remain in standardization, data integration, and alignment between regulatory frameworks and industrial practice. This work positions SSbD as a central paradigm for enabling responsible innovation and accelerating the transition toward safer and more sustainable nanotechnologies.
Reducing the Ru content while maintaining high oxygen evolution reaction (OER) activity remains a major challenge. In this study, single phase Ru0.30Cr0.31Mn0.39O2 nanofibers were prepared through electrospinning process followed by temperature-regulated heat treatment. The temperature regulation process induces a unique formation of a hollow tube-in-tube structure while simultaneously influencing crystallinity and defect distribution. Among the prepared samples, the material treated at 400 °C shows the most favorable performance for OER. This behavior is associated with improved transport properties and increased accessibility of catalytically active sites. The catalyst reaches an overpotential of only 211 mV at 10 mA cm− 2 and maintains stable operation in alkaline electrolyte. The mass-normalized activity and turnover frequency (TOFmetal) are significantly 293- and 104-fold higher than those of commercial RuO2, respectively, highlighting its superior catalytic efficiency with reduced Ru content. Theoretical calculations based on density functional theory suggest that the incorporation of Cr and Mn modulates the electronic structure of RuO2, particularly near the Fermi level, and adjusts the d-band center position. These changes lower the energy barrier associated with the O* to OOH* step. The results thus demonstrate that simultaneous control of composition and morphology can improve OER performance in alkaline media.
Two-terminal (2T) monolithic CIGS/perovskite tandem solar cells exploit complementary light-absorption characteristics to approach the theoretical Shockley–Queisser (SQ) efficiency limit ( 45
