A chronic wound in diabetic patients is a major public health concern with socioeconomic and clinical manifestations. The underlying medical condition of diabetic patients deteriorates the wound through physiological, metabolic, molecular, and cellular pathologies. Consequently, a wound enters a vicious pathological inflammatory cycle. Many therapeutic approaches are in practice to manage diabetic wounds hence ensuring the regeneration process. Polymer-based biomaterials have come up with high therapeutic promises. Many efforts have been devoted, over the years, to build an effective wound healing material using polymers. The electrospinning technique, although not new, has turned out to be one of the most effective strategies in building wound healing biomaterials due to the special structural advantages of electrospun nanofibers over the other formulations. In this review, careful integration of all electrospinning approaches has been presented which will not only give an insight into the current updates but also be helpful in the development of new therapeutic material considering pathophysiological conditions of a diabetic wound.
With the rapid improvements in nanomaterials and imaging technology, great progresses have been made in diagnosis and treatment of diseases during the past decades. Fe3O4 magnetic nanoparticles (MNPs) with good biocompatibility and superparamagnetic property are usually used as contrast agent for diagnosis of diseases in magnetic resonance imaging (MRI). Currently, the combination of multiple imaging technologies has been considered as new tendency in diagnosis and treatment of diseases, which could enhance the accuracy and reliability of disease diagnosis and provide new strategies for disease treatment. Therefore, novel contrast agents used for multifunctional imaging are urgently needed. Fe3O4 MNPs are believed to be a potential candidate for construction of multifunctional platform in diagnosis and treatment of diseases. In recent years, there are a plethora of studies concerning the construction of multifunctional platform presented based on Fe3O4 MNPs. In this review, we introduce fabrication methods and modification strategies of Fe3O4 MNPs, expecting great improvements for diagnosis and treatment of diseases in the future.
With the rapid development of wearable smart devices, many researchers have carried out in-depth research on the stretchable electrodes. As one of the core components for electronics, the electrode mainly transfers the electrons, which plays an important role in driving the various electrical devices. The key to the research for the stretchable electrode is to maintain the excellent electrical properties or exhibit the regular conductive change when subjected to large tensile deformation. This article outlines the recent progress of stretchable electrodes and gives a comprehensive introduction to the structures, materials, and applications, including supercapacitors, lithium-ion batteries, organic light-emitting diodes, smart sensors, and heaters. The performance comparison of various stretchable electrodes was proposed to clearly show the development challenges in this field. We hope that it can provide a meaningful reference for realizing more sensitive, smart, and low-cost wearable electrical devices in the near future.
Recent years witnessed a growing research interest in graphene-reinforced aluminum matrix composites (GRAMCs). Compared with conventional reinforcements of aluminum matrix composites (AMCs), graphene possesses many attractive characteristics such as extremely high strength and modulus, unique self-lubricating property, high thermal conductivity (TC) and electrical conductivity (EC), and low coefficient of thermal expansion (CTE). A lot of studies have demonstrated that the incorporation of graphene into Al or Al alloy can effectively enhance mechanical and physical properties of the Al matrix. The purpose of this work is aimed to trace recent development of GRAMCs. Initially, this paper covers a brief overview of fabrication methods of GRAMCs. Then, mechanical, tribological, thermal and electrical properties of recently developed GRAMCs are presented and discussed. Finally, challenges and corresponding solutions related to GRAMCs are reviewed.
A glucose-mediated drug delivery system would be highly satisfactory for diabetes diagnosis since it can intelligently release drug based on blood glucose levels. Herein, a glucose-responsive drug delivery system by integrating glucose-responsive poly(3-acrylamidophenylboronic acid) (PAPBA) functionalized hollow mesoporous silica nanoparticles (HMSNs) with transcutaneous microneedles (MNs) has been designed. The grafted PAPBA serves as gatekeeper to prevent drug release from HMSNs at normoglycemic levels. In contrast, faster drug release is detected at a typical hyperglycemic level, which is due to the change of hydrophilicity of PAPBA at high glucose concentration. After transdermal administration to diabetic rats, an effective hypoglycemic effect is achieved compared with that of subcutaneous injection. These observations indicate that the designed glucose-responsive drug delivery system has a potential application in diabetes treatment.
We exploited a unique porous structure of the nano-covalent triazine polymer (NCTP) containing aggregation-induced emission (AIE) group to achieve controlled release and drug tracking in tumor acidic microenvironment. NCTP was synthesized by the Friedel–Crafts alkylation and the McMurry coupling reaction. It not only had strong doxorubicin (DOX)-loading capacity due to its high specific surface area and large pore volume, but also showed the significant cumulative drug release as a result of the pH response of triazine polymers. NCTP was induced luminescence after mass accumulation near tumor cells. Besides, it had excellent biocompatibility and obvious antineoplastic toxicity. The results demonstrate that NCTP as a utility-type drug carrier provides a new route for designing the multi-functional drug delivery platform.
The fundamental relationship between microstructure, constituent, processing and performances of separating materials is really a vital issue. Traditional preparation methods for separation membranes are complex, time-consuming and easy to be fouled. Also, the durability of conventional coatings on membrane is poor. By combination of bioinspiration from mussel adhesive and fish scales’ underwater superoleophobicity, we propose a general route to prepare organic–inorganic hybrid coatings, while no complex apparatus is needed. Specifically, based on the biomimetic adhesion of polydopamine (PDA), we used it as a binder to adhere TiO2 nanoparticles and built rough microstructure on fabric. In this way, we obtained TiO2-PDA treated fabric with special wettability. These TiO2-PDA treated samples owned superamphiphilicity in air, underwater superoleophobicity (underwater oil contact angles (OCAs)>150°), underoil superhydrophobicity (underoil water contact angles (WCAs)>150°), excellent multi-resistance; and can separate polar/nonpolar liquid mixture effectively. It also owned superaerophobicity underwater (underwater bubble contact angles (BCAs)>150°). The proposed TiO2-PDA coatings are highly expected to be employed for real situation of water pollution remediation, self-cleaning, oil extraction and harsh chemical engineering issues.
Solar-driven evaporation has been considered as one of the potential methods for desalination and sewage treatment. However, optical concentrators and complex multi-component systems are essential in advanced technologies, resulting in low efficiency and high cost. Here, we synthesize a reduced graphene oxide-based porous calcium alginate (CA-rGO) hydrogel which exhibits good performance in light absorption. More than 90% of the light in the whole spectrum can be absorbed. Meanwhile, the water vapor escapes from the CA-rGO film extremely fast. The water evaporation rate is 1.47 kg·m−2·h−1, corresponding to the efficiency 77% under only 1 kW·m−2 irradiation. The high evaporation efficiency is attributed to the distinctive structure of the film, which contains inherent porous structure of hydrogel enabling rapid water transport throughout the film, and the concave water surfaces formed in the hydrophilic pores provide a large surface area for evaporation. Hydrophobic rGO divides the evaporation surface and provides a longer three-phase evaporation line. The test on multiple cyclic radiation shows that the material has good stability. The CA-rGO hydrogel may have promising application as a membrane for solar steam generation in desalination and sewage treatment.
We demonstrated a simple and environment-friendly method in the preparation of N-doped carbon/PANI (NCP) composite without binder. The structure and the property of NCP have been characterized by XPS, IR, XRD, SEM, CV, GCD and EIS. The results reveal that NCP has high capacitance performance of up to 615 F·g−1 at 0.6 A·g−1. Additionally, the asymmetric NCP300//carbon supercapacitor delivers a high capacitance (111 F·g−1 at 1 A·g−1) and a capacity retention rate of 82% after 1200 cycles at 2 A·g−1. The ASC cell could deliver a high energy density of 39.1 W·h·kg−1 at a power density of 792.6 W·kg−1.
In this work, a sky-blue luminescent down-shifting (LDS) layer bis[(4,6-difluorophenyl)-pyridinato-N,C2′]c(picolinate)iridium(III) (FIrpic) was inserted between tetraphenyldibenzoperiflanthene (DBP) and MoO3 as UV-screen and sensitizer for small molecule DBP/C60 based planar heterojunction (PHJ) solar cells. With 8-nm FIrpic the short circuit current (Jsc) and power conversion efficiency (PCE) of the device are enhanced by 28% and 15%, respectively, probably originating from the re-absorption of the photons emitted from FIrpic. The Voc linearly increases over 1-nm FIrpic, ascribed to the deeper HOMO level of FIrpic than DBP, while the fill factor continuously declines from 3- to 10-nm FIrpic. The EQE spectra prove that the Jsc is mainly contributed by the photocurrent generated in DBP and C60 layers. When the FIrpic thickness is 8 nm, the film surface is very uniform with the smallest water contact angle. The impedance spectroscopy demonstrates that the device resistance gradually increases from 4.1×104 W (without FIrpic) to 4.6×104 W (with 10-nm FIrpic) with the FIrpic thickness rise, simultaneously the device transits from the insulating state into the conductive state faster for the thin FIrpic layer than the thick layer.