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The sensing performance of gas sensors is determined by three key factors of sensing, transducing and utilization ratio of sensing body. However, these three factors are structurally and functionally independent for most existing gas sensors, restricting the integration and multi-functionalization of the gas discrimination. Herein, we reported a ternary ordered assembly strategy to synchronously and sympatrically integrate and optimize the three key factors in one single device. The in-situ polymerized Ppy coating serves as the sensing component while the embedded PZT nanofiller functions as transducing element, where the utilization ratio of sensing body is directly regulated by the porosity and sensing coating thickness via controlling the sugar granule loading amount and polymerization time. By tuning in-situ polymerization quantity, sacrificial templating amount and transducing loading as well as poling time, an optimal ammonia sensing response was accomplished with a responsivity of 387% at the 100 ppm, a sensitivity of 4.29% ppm−1, excellent selectivity and long-term stability. A theoretical gas-sensitive model was established by combining the experimental characterization with finite element calculation and phase-field simulation. This work throws lights on the fundamental gas sensing mechanism and provides a promising paradigm for developing multi-level controllable sensing devices for physiological assessment and environmental monitoring. [Display omitted] A ternary ordered assembly strategy synergizes all the three key factors of gas sensors. Sensing, transducing and utilization ratio of the sensing body were coupled and tuned. A responsivity of 387% at 100 ppm NH 3 and sensitivity of 4.29% ppm−1 was achieved. A theoretical model was established by combining experimental analysis and simulation. [ABSTRACT FROM AUTHOR]

• TiO 2 nanotubes promote osteogenic differentiation of MSCs. • The related lncRNAs and their target genes are identified by RNA sequencing. • LncRNA CCL3-AS downregulates osteogenic differentiation of MSCs on TiO 2 nanotubes. • CCL3 inhibits osteogenic differentiation of MSCs downstream of lncRNA CCL3-AS. Titanium (Ti) is widely used as orthopedic implant materials. TiO 2 nanotubes (TNTs) further improve the bioactivity of Ti, which enhance the osteogenic differentiation of mesenchymal stem cells (MSCs). However, the underlying mechanism is still unclear. In this study, we verified the response of MSCs on Ti and TNT substrates and explored the regulatory mechanism of long non-coding RNAs (lncRNAs). LncRNA and mRNA expression profiles were analyzed via RNA sequencing. Differential lncRNA and mRNA expression and predicted target genes of lncRNAs were performed by bioinformatics analysis. 1075 up-regulated and 1301 down-regulated genes, 26 up-regulated and 35 down-regulated lncRNAs were obtained according to the RNA-Seq. Expression of 8 lncRNAs were verified by qPCR, which was consistent with the sequencing data. To explore the function and target gene of lncRNA, lncRNA CCL3-AS and gene CCL3 were selected for further investigation. The fluorescence staining, alkaline phosphatase (ALP) activity and CCK-8 assay were performed. Besides, expressions of runt-related transcription factor 2 (Runx2), collagen type I (Col I), osteopontin (OPN) were detected by qPCR and western blot. These results indicate that lncRNA CCL3-AS could inhibit the osteogenic differentiation and enhance cell viability of MSCs on the TNT substrates, which was dependent on the regulation of CCL3. This study supplied a comprehensive understanding for further study using lncRNA modulators to surface design of titanium for enhancing osseointegration. [ABSTRACT FROM AUTHOR]

[Display omitted] • Capillary-based microfluidic manipulation of PLGA microcarriers. • Collagen patchy structure on microcarriers for MSCs delivery. • Regulation of MSCs expansion/osteogenic differentiation via collagen content. This study was aimed to develop a capillary-based microfluidic methodology for preparing poly (lactic-co-glycolic acid) (PLGA) microcarriers patterned with collagen patchy structure (PLGA-Col), which are superior in enhancing proliferation and osteogenic differentiation of mesenchymal stem cells (MSCs) seeded on them. Primary W/O emulsions were first prepared using aqueous collagen and PLGA solutions. A two-phase microfluidic device was then designed and the emulsions were used as the inner liquid phase to obtain PLGA-Col microcarriers. The content of collagen was varied to yield PLGA-Col-L (lower collagen content) and PLGA-Col-H (higher collagen content). The proliferation behavior of the cells on the microcarriers was evaluated by live/dead cell staining and CCK-8 assays, while the osteogenic differentiation behavior was evaluated by ALP and qRT-PCR assays. Pristine PLGA microcarriers were also prepared to serve as a control. Three groups, PLGA, PLGA-Col-L, and PLGA-Col-H were then obtained. PLGA-Col was asymmetric with a rough/porous collagen patchy structure. All of these microcarriers could maintain morphology integrity for at least 3 weeks in the aqueous medium before undergoing obvious swelling (5w) and further erosion (7w). It was demonstrated that PLGA-Col could not only enhance the MSCs adhesion/proliferation but also mediate their subsequent osteogenic differentiation. PLGA-Col-L was suitable for supporting the MSCs proliferation, while PLGA-Col-H was more efficient in promoting the osteogenic differentiation of MSCs. Hence, the incorporation of collagen as a patchy structure into PLGA microspheres through the current microfluidic method could be an effective strategy to provide a superior type of microcarriers with well-defined functionality. [ABSTRACT FROM AUTHOR]