Currently, combining biomaterial scaffolds with living stem cells for tissue regeneration is a main approach for tissue engineering. Mesenchymal stem cells (MSCs) are promising candidates for musculoskeletal tissue repair through differentiating into specific tissues, such as bone, muscle, and cartilage. Thus, successfully directing the fate of MSCs through factors and inducers would improve regeneration efficiency. Here, we report the fabrication of graphene oxide (GO)-doped poly(lactic-co-glycolic acid) (PLGA) nanofiber scaffolds via electrospinning technique for the enhancement of osteogenic differentiation of MSCs. GO-PLGA nanofibrous mats with three-dimensional porous structure and smooth surface can be readily produced via an electrospinning technique. GO plays two roles in the nanofibrous mats: first, it enhances the hydrophilic performance, and protein- and inducer-adsorption ability of the nanofibers. Second, the incorporated GO accelerates the human MSCs (hMSCs) adhesion and proliferation versus pure PLGA nanofiber and induces the osteogenic differentiation. The incorporating GO scaffold materials may find applications in tissue engineering and other fields.

This paper demonstrates a sulfur dioxide (SO2) gas sensor based on a transition-metal-doped molybdenum disulfide (MoS2) nanocomposite synthesized via a facile single-step hydrothermal route.

Metal-organic frameworks (MOFs) with high porosity and designable functionality make it possible to access the merits of high permeability and selectivity. However, scalable fabrication methods to produce mixed matrix membranes (MMMs) with good flexibility and ultrahigh MOF loading are urgently needed yet largely unmet. Herein, we report a thermally induced phase separation-hot pressing (TIPS-HoP) strategy to roll-to-roll produce 10 distinct MOF-membranes (loadings up to 86 wt%). Ultrahigh-molecular-weight polyethylene interweaving the MOF particles contributes to their mechanical strength. Rejections (99%) of organic dyes with a water flux of 125.7 L m–2 h–1 bar–1 under cross-flow filtration mode. The micron-sized channels between the MOF particles translate into fast water permeation, while the porous MOFs reject solutes through rapid adsorption. This strategy paves ways for developing high-performance membrane adsorbers for crucial separation processes. As a proof-of-concept, the abilities of the membrane adsorbers for separating racemates and proteins have been demonstrated.

Photothermal therapy (PTT) is a noninvasive and convenient way to ablate tumor tissues. Integrating PTT with imaging technique could precisely identify the location and the size of tumor regions, thereby significantly improving the therapeutic efficacy. Magnetic resonance imaging (MRI) is widely used in clinical diagnosis due to its superb spatial resolution and real-time monitoring feature. In our work, we developed a theranostic nanoplatform based on manganese doped iron oxide (MnIO) nanoparticles modified with denatured bovine serum albumin (MnIO-dBSA). The in vitro experiment revealed that the MnIO nanoparticles exhibited T1-weighted MRI capability (r1 = 8.24 mM(-1) s(-1), r2/r1 = 2.18) and good photothermal effect under near-infrared laser irradiation (808 nm). Using 4T1 tumor-bearing mice as an animal model, we further demonstrated that the MnIO-dBSA composites could significantly increase T1 MRI signal intensity at the tumor site (about two times) and effectively ablate tumor tissues with photoirradiation. Taken together, this work demonstrates the great potential of the MnIO nanoparticles as an ideal theranostic platform for efficient tumor MR imaging and photothermal therapy.

Nowadays, one of the most challenging sustainability issues faced by society is the safety of water resources. Water pollution caused by hazardous contaminants (e.g., heavy metal ions, emerging contaminants, organic dyes) is a serious issue because of acute toxicities and the carcinogenic nature of the pollutants. With the advent of materials engineering, unprecedented technical advances have been achieved through diverse technologies in recent decades, including photocatalytic oxidation, photo-Fenton, electron Fenton, adsorption, and separation. However, the applications of these technologies have suffered from several limitations, such as the uncompleted degradation efficiency, high energy consumption, narrow pH range for application etc. Metal–organic frameworks (MOFs) have aroused increasing studies in gas storage, separation, sensing, water/air purification, and catalysis. The effectiveness of the above applications has been extensively recognized. In recent years, these highly ordered and porous crystalline structures have been recognized as a potential alternative to overcome the technical limitations in the area of water pollution control. This perspective article reports recent progress in the applications of MOFs in the field of environmental pollutant elimination, including the adsorption, advanced oxidation process (AOP) heterogeneous Fenton-like reactions, and MOF-based membranes for pollutant filtration.

A high-performance formaldehyde sensor based on nickel (Ni)-doped indium trioxide (In2O3)/tungsten disulfide (WS2) nanocomposite was demonstrated. An epoxy substrate served as matrix of the Ni–In2O3/WS2 nanocomposite sensor. The material properties of self-assembled Ni–In2O3/WS2 nanoheterostructure were fully characterized and confirmed. The formaldehyde-sensing properties of the Ni–In2O3/WS2 composite were tested at 25 °C. Compared to the In2O3, WS2, and their composite, the Ni–In2O3/WS2 sensor demonstrated significant improvement on the formaldehyde-sensing performance, including a low detection limit of 15 ppb, good selectivity, repeatability, fast detection rate, and a fair logarithmic function toward formaldehyde concentration. The dramatically enhanced sensing performance of Ni–In2O3/WS2 film sensor can be attributed to the Ni ion doping and synergistic interfacial incorporation of In2O3/WS2 heterojunction. The sensitive mechanism of the Ni–In2O3/WS2 film sensor toward formaldehyde is explored through density functional theory (DFT) simulation. This work verified that the synthesis of Ni-doped In2O3/WS2 nanofilm provides a new avenue to develop promising hybrids for formaldehyde sensing.

Magnetic resonance imaging (MRI) is a powerful and widely used clinical technique in cancer diagnosis. MRI contrast agents (CAs) are often used to improve the quality of MRI-based diagnosis. In this work, we developed a positive T1 MRI CA based on graphene oxide (GO)-gadolinium (Gd) complexes. In our strategy, diethylenetriaminepentaacetic acid (DTPA) is chemically conjugated to GO, followed by Gd(III) complexation, to form a T1 MRI CA (GO-DTPA-Gd). We have demonstrated that the GO-DTPA-Gd system significantly improves MRI T1 relaxivity and leads to a better cellular MRI contrast effect than Magnevist, a commercially used CA. Next, an anticancer drug, doxorubicin (DOX), was loaded on the surface of GO sheets via physisorption. Thus-prepared GO-DTPA-Gd/DOX shows significant cytotoxicity to the cancer cells (HepG2). This work provides a novel strategy to build a GO-based theranostic nanoplatform with T1-weighted MRI, fluorescence imaging, and drug delivery functionalities.

Adjuvants play an important role in vaccines. Alum and MF59 are two dominant kinds of adjuvants used in humans. Both of them, however, have limited capacity to generate the cellular immune response required for vaccines against cancers and viral diseases. It is desirable to develop new and effi cient adjuvants with the aim of improving the cellular immune response against the antigen. Here, the feasibility and effi ciency of ultrasmall graphene oxide supported gold nanoparticles (usGO-Au) as a new immune adjuvant to improve immune responses are explored. usGO-Au is obtained from reduction of chloroauric acid using usGO and then decorated with ovalbumin (OVA, a model antigen) through physical adsorption to construct usGO-Au@ OVA. As the results show, the as-synthesized usGO-Au@OVA can effi ciently stimulate RAW264.7 cells to secrete tumor necrosis factor-α (TNF-α), a mediator for cellular immune response. In vivo studies demonstrate that usGO-Au@OVA can also promote robust OVA specifi c antibody response, CD8 + T cells proliferation, and different cytokines secretion. The results indicate that using usGO-Au as an adjuvant can stimulate potent humoral and cellular immune responses against antigens, which may promote better understanding of cellular immune response and facilitate potential applications for cancer and viral vaccines.