Latest ArticlesDroplet-based microfluidics enables the generation of uniform microdroplets at picoliter or nanoliter scale with high frequency (~kHz) under precise control. The droplets can function as bioreactors for versatile chemical/biological study and analysis. Taking advantage of the discrete compartment with a confined volume, (1) isolation and manipulation of a single cell, (2) improvement of in-droplet effective concentrations, (3) elimination of heterogeneous population effects, (4) diminution of contamination risks can be achieved, making it a powerful tool for rapid, sensitive, and high-throughput detection and analysis of bacteria, even for rare or unculturable strains in conventional methods. This mini-review will focus on the generation and manipulation of micro-droplets and bacteria detection and analysis carried out by droplet-based microfluidics. Finally, applications with high potential of droplet-based bacteria analysis are briefly introduced. Due to the advantages of rapid, sensitive, high throughput, and compatibility with rare and unculturable bacteria in conventional methods, droplet-based microfluidics has tremendous potential of providing novel solutions for biological medicine, microbiological engineering, environmental ecology, etc.
Glutathione (GSH) is a key maintainer of cellular redox balance and plays an important role in many physiological effects. For example, GSH has been widely implicated in cancer initiation, progression and metastasis. Moreover, the concentrations of GSH in tumor cells can influence drug resistance. Given the serious harmfulness of cancer and the important roles of GSH in cancer, it has great significance to development probes for screening of tumor cells and real-time monitoring of GSH fluctuations in tumor cells. However, no targetable probe for reversible imaging of GSH in tumor cells has been reported. Herein, we constructed a melatonin-based targetable and reversible fluorescent probe (GR-MT) for screening of tumor cells and real-time imaging of GSH fluctuations in tumor cells. The probe uses coumarin as the skeleton, Michael addition reaction as the reaction mechanism, and melatonin as the targeted groups of tumor cells. The experimental results demonstrate this probe has many advantages including high selectivity, satisfactory sensitivity, excellent reversible ability, rapid reaction speed, and outstanding targetability of tumor cells. Therefore, this study provides a promising tool for tumor cells screening and real-time detection of GSH fluctuations in specific tumor cells.
Complex coordinated functional groups [MAxBy] (M = Central coordination element; A, B = P, O, S, Se, F, Cl, Br or I) are composed of different types of anions A, B jointly linked to the same central cation M, which are in high potential to tune the physical properties of materials, e.g., second-order susceptibility, energy gaps and birefringence. Recently, Compound containing complex coordinated functional groups have attracted great attention in the nonlinear optical (NLO) field and a large number of this type crystals exhibit promising NLO performance. However, the inherent relationship between ionic group structure and optical properties of complex coordinated NLO materials have not been systematically studied. This article systematically summarizes complex coordinated NLO materials in recent five years from the perspective of the internal relationship between crystal structure and optical properties. In addition, we propose the ideal combination and arrangement modes for structural building units, and also reveal the influence of complex coordinated functional groups [MAxBy] toward the NLO response, optical band gap and phase matching ability of complex coordinated NLO materials.
Developing phosphors with long-lifetime (millisecond scale or even longer) solid state room temperature phosphorescence (RTP) feature has attracted considerable attention. However, to date, stimuli-responsive phosphors with RTP nature are still rare due to the absence of effective guidelines for the exploitation of luminophors synchronously possessing stimuli-responsive and RTP characteristics. In this work, a series of mononuclear gold(I) complexes are reported. All these complexes exhibit various solid-state RTP properties, and phosphor 1-Cl exhibits long-lived RTP behavior. The effect of halogen atoms on the RTP nature of these complexes is investigated in detail. Furthermore, the introduction of different types of halogen atoms can effectively regulate the phosphorescent mechanochromism phenomena of these gold(I)-containing complexes. In addition, these phosphors display typical aggregation-induced emission (AIE) effect except for phosphor 5-CCl, which lacks hydrogen-bonding interactions compared with the other four phosphors. This work will be very helpful to the development of mechanical-force-responsive AIE phosphors with lasting RTP.
Two-dimensional (2D) materials composed of single pnictogen element, namely, 2D pnictogens (e.g., black phosphorus, arsenene, antimonene and bismuthine), have recently showed remarkable potential for biomedical applications, especially after the rapid development of black phosphorus. With unique optical and electronic properties, 2D pnictogens are considered as promising nanoagents for biosensors, diagnosis and therapy. In this review, after brief introduction of the structure, properties, synthesis strategies, and biocompatibility of 2D pnictogens, their biomedical applications including anti-tumor, anti-inflammation, anti-bacterial, neurodegenerative treatment and tissue repairing are reviewed. The major obstacles and opportunities of 2D pnictogens are also discussed. This review provides a short yet timely summary on the synthesis and biomedical applications of emerging 2D pnictogens.
Stimuli-responsive hydrogels hold an irreplaceable statue in intelligent actuation materials because of their reversible stretchability and excellent biocompatibility. However, the poor mechanical performance and complicated fabrication process of anisotropic structures severely limit their further applications. Herein, we report a high-strength thermoresponsive wood-PNIPAM composite hydrogel actuator with complex deformations, through a simple in-situ polymerization. In this composite hydrogel actuator, the anisotropic wood and the thermoresponsive PNIPAM hydrogel hydroel can work together to provide bending and even other complex deformations. Owing to strong interfacial interaction, this actuator perfectly realized the combination of good mechanical properties (~1.1 MPa) and fast actuation speed (~0.9 s). In addition, by adjusting the orientation direction of wood, this actuator can achieve various complex deformations. Such composite hydrogel actuator could be a good candidate for intelligent applications, such as intelligent actuators, smart valves, manipulators and even soft robots.
To test the hypothesis that the microviscosity changes of Endoplasmic Reticulum (ER) can be a useful indicator of ferroptosis promoted by ER Stresses (ERS), a new ER targeting viscosity rotor, L-Vis-1 was developed and applied in the quantitation of viscosity by FLIM imaging in live cells. The FLIM imaging exhibited an excellent resolution almost as good as the corresponding confocal imaging, more significantly, during ferroptosis processes promoted by different types of ERS, the viscosity increases were clearly monitored by FLIM of L-Vis-1 within ER, which has not been demonstrated before.
Osteoporosis (OP) is a noncommunicable bone disease caused by a shift in the balance between osteoblasts and osteoclasts, and can severely affect the health of elderly persons. Autologous stem-cell transplantation can improve reduced bone density and weakened fracture healing abilities in patients with OP. However, OP can adversely affect the osteogenesis and proliferation abilities of autologous adipose-derived stem cells (ASCs). Therefore, an effective drug is required to facilitate autologous ASCs to recover their osteogenic and proliferative potential. Tetrahedral framework nucleic acid (tFNA) is a new type of nanomaterial that has ability to regulate the biological behavior of cells effectively and enhance the bioactivity of stem cells. In this study, we examine the effects of tFNAs on the osteogenic differentiation and proliferation abilities of ASCs in rats with OP. The results indicate that the 250 nmol/L tFNAs can considerably increase the expression of osteogenesis-related markers, effectively promote the proliferation and osteogenic differentiation of osteoporotic ASCs (OP-ASCs), and help them to regain their osteogenic and proliferative potential. In short, tFNAs can enable OP-ACSs to recover their osteogenic potential and promote their proliferation and, therefore, can play a key regulatory role in autologous ASC transplantation.
Nowadays, there are still many challenges to skin regeneration. As a new type of skin substitute, hydrogel has emerging gradually with its excellent properties. However, it is still a challenge to combine with biological active agents to facilitate skin regeneration. Under the circumstance, we synthesized arginine-based poly(ester amide) (Arg-PEA) and hyaluronic acid (HA-MA), and combined them into new hybrid hydrogels via photo-crosslinking. We found that the internal structure and physicochemical properties of hybrid hydrogels were greatly improved with the increase of content of Arg-PEA. Therefore, we designed hybrid hydrogels with 5 wt% and 10 wt% of Arg-PEA content, respectively. Besides, we selected the corresponding anti-inflammatory (CRP, TNF-α) indicators to detect the anti-inflammatory properties of the hybrid hydrogels at the protein level, and the corresponding antioxidant indicators (SOD, GSH/GSSG, MDA) were selected to investigate the antioxidant properties of hybrid hydrogels at the cellular level in vitro. In addition, we also selected relevant genes to test the effect of hybrid hydrogels on fibrosis and vascularization in the process of skin wound healing in vitro and verified them in vivo with a mouse dorsum wound model. The results confirmed that Arg-PEA/HA-MA (AH) hybrid hydrogel was a prospective scaffold material for skin regeneration.