Latest ArticlesListeriosis is caused by Listeria monocytogenes (LM) and is currently considered to be one of the leading food-borne diseases worldwide, with mortality rate of 20%~30%. Currently, detection methods for LM are time-consuming with low sensitivity, and delayed detection results. SYTO9 has a high affinity for DNA and exhibits enhanced fluorescence upon binding. Therefore, this study used SYTO9 staining and image processing to develop a rapid loop mediated isothermal amplification (LAMP) detection method for LM. Smartphone was successfully used for detecting the color change in different concentrations of LM. Besides, the optimized LAMP reaction temperature was 63 ℃ by color identification, and the limit of detection for LM was 6 copies/µL in the green channel. So, the developed method, based on image processing, is simple, sensitive and rapid, which provides a new idea and method for rapid detection of LM and other food-borne bacterial pathogens.
Since self-assembled peptide hydrogels can solve the problems such as low solubility, poor selectivity and serious adverse effects of traditional chemotherapy drugs, they have been widely used as carrier materials for drug delivery. In this study, we developed a novel and injectable drug delivery platform for the antitumor drug doxorubicin (DOX) using a pH-responsive ionic-complementary octapeptide FOE. This octapeptide could self-assemble into stable hydrogel under neutral conditions, while disassemble under the tumor microenvironment. Especially, at pH 5.8, its micromorphology displayed a transition from nanofibers to nanospheres with the change of secondary structure, which enhanced cellular uptake of DOX. In addition, FOE hydrogel serves as a smart drug reservoir by localized injection to achieve sustained drug release and improve antitumor efficacy. This octapeptide opens up new avenues for promoting the clinical translation of anticancer drugs on account of excellent injectable properties and economic benefits of simple and short sequence.
A high incidence of bone defects and the limitation of autologous bone grafting require 3D scaffolds for bone repair. Compared with synthetic materials, natural edible materials possess outstanding advantages in terms of biocompatibility, bioactivities and low manufacturing cost for bone tissue engineering. In this work, attracted by the natural porous/fabric structure, good biocompatibility and bioactivities of the lotus root, the lotus root-based scaffolds were fabricated and investigated their potential to serve as natural porous bone tissue engineering scaffolds. The results indicated that the lotus root-based scaffolds possess suitable natural microstructure, excellent biocompatibility and promising functions, such as antioxidant capacity and angiogenesis promotion. Remarkably, lotus root scaffolds showed encouraging possibility of bone tissue engineering while the mineralized lotus root could further improve the bone regeneration in vivo. All the results demonstrated the bone regeneration potential of lotus root-based scaffolds equipped with suitable natural architecture, excellent biocompatibility, specific bioactivities and low manufacturing cost.
There is a critical need to diagnose and monitor the progression of Alzheimer's disease (AD) using blood-based biomarkers. At present, it is believed that tau biomarkers can be utilized to reliably detect AD. Multimodal techniques are highly sought after for AD diagnosis and progression monitoring. For this purpose, we developed a fluorescent peptide nanoparticles (f-PNPs) arrays that is capable of detecting multiple signals simultaneously. The concentration, aggregation stages, and Young's modulus of tau biomarkers could be analyzed by monitoring the changes of multimodal fluorescence intensity, nano-morphological, and nano-mechanical properties of the f-PNPs arrays. Experimental results indicated that, compared to healthy human, the concentration, Young's modulus, and aggregation levels of tau proteins in blood samples of clinically diagnosed AD patients increased continuously with the increase of disease severity. The minimally invasive and multimodal characterization techniques showed high signal-to-noise ratio for AD diagnosis.
Dye desalination is a challenge in the treatment of textile wastewater with high salt concentration. It is imperative to develop salt resistance membrane that is from sustainable materials to effectively treat dye/salt mixtures. And most polymer membrane materials are non-renewable petrochemical resources. In this paper, a green hydrogel membrane (CMCS-OA-NaAlg) was prepared by non-metallic ions of oxalic acid (OA) cross-linking of two natural macromolecules of sodium alginate (NaAlg) and carboxymethyl chitosan (CMCS). The membrane showed excellent anti-swelling at high salt concentration (swelling rate less than 8.0% in 10.0 wt% NaCl solution) and good anti-fouling performance. The membrane exhibited a rejection higher than 95.0% for dyes (bright blue, direct black, direct red, and Congo red) and lower than 7.0% for NaCl, which can achieve better dye/NaCl separation performance. This study provides a promising membrane material for high salt textile wastewater treatment only using water and carbohydrates as raw materials without any organic solvents.
A poor biocompatibility and bioactivity of invasive materials remains major problems for biomaterial-based therapy. In this study, we introduced gelatin scaffolds carrying both bone morphogenetic protein-2 (BMP-2) biomimetic peptide and vascular endothelial growth factor-165 (VEGF) that achieved controlled release, cell attachment, proliferation and differentiation. To promote osteogenesis with VEGF, we designed the BMP-2 biomimetic peptide that comprised BMP-2 core sequence oligopeptide (SSVPT), phosphoserine, and synthetic cell adhesion factor (RGDS). In vitro cell experiments, the scaffold was conducive to the adhesion and proliferation of rat bone marrow mesenchymal stem cells (rBMSCs). The micro-CT 3D reconstruction of the rat cranial bone defect model showed that bone regeneration patterns occurred from one side edge towards the center area implanted with the prepared cryogel, and tissue section staining analysis demonstrated that the scaffold with double-growth factor can synergistically accelerate bone regeneration. These findings suggested that the obtained gelatin cryogel could serve as a cell-responsive platform for biomaterial-based nonbearing bone repair.
In clinical settings the wound-dressing was required easy to use and can match the wound area immediately, at the same time they need to have the properties of hemostats, anti-inflammation and promoting wound healing. To get an ideal wound dressing, we developed a type of gel-like wound adhesive patch from spraying double-network hydrogel, which own the properties of self-antibacterial and can promote wound healing. By spraying, the gel-like wound adhesive patch can match the wound area immediately and form a gel-film in 10 s. Sodium carboxymethyl cellulose as pH sensitive materials accelerated the speed to form the gel-film and enhanced ductility of the wound adhesive patch. In vitro experiments show that, this gel-like wound adhesive patch can promote cell proliferation and reduce cell apoptosis. In vivo studies show that, compared with commercialized wound dressings in clinic using, the spraying gel-like wound adhesive patch from our work has a better effect on wound healing. In conclusion, the spraying gel-like wound patch in our work is easy to use and can form a gel-film match on wound area in a short time, also it has the properties of hemostats, anti-inflammation and promoting wound healing. Its feasibility for mass production shows a good potential for commercial use.
Polyhaloalkanes are broadly useful yet environmentally harmful stock chemicals, therefore the development of adsorbent materials with capacity and selectivity for polyhaloalkane vapors is highly desirable. Here we report a novel macrocycle WreathArene, a fluorinated C3-symmetrical [16]-paracyclophane. In the crysalline state, WreathArene features guest-adaptive polymorphism for polyhaloalkanes including chloroform, tribromomethane, 1,1,2-trichloroethane, and 1,2-dibromoethane. Non-covalent C-halogen…π interactions are observed in all of these host-guest structures. Based on these properties, the activated WreathArene crystals can be utilized as a selective and recyclable adsorbent for polyhaloalkane vapors with excellent capacity under user-friendly conditions.
Novel aggregation-induced charge transfer (CT) emission systems with long luminescence lifetime directed by supramolecular strategy have been successfully developed in water. The dimethylacridine-based electron donor (BrAc) with excellent aggregation ability can co-aggregate with a triazine-based electron acceptor (TRZ) to form nanorods in water, which exhibit CT emission with long lifetime (τ = 0.92 µs). As for a similar electron donor (QaAc) with poor aggregation ability, water-soluble pillar[5]arene (WP5) can be introduced to promote the aggregation process, leading to the obvious CT emission with long lifetime (τ = 0.61 µs). In addition, structural modification of the acceptor with substituent groups possessing stronger electron-accepting capabilities will cause red-shift (about 50 nm) of the emission, which allows conveniently constructing long lifetime organic luminescent materials with different emission colors.
Dansylamide (DNSA) is a typical ICT probe that has a favorable serum albumin sensitivity. Inspired by this, we designed a microenvironment sensitive fluorescent probe 4C-G through introducing DNSA into pillar[5]arene. Unlike DNSA, 4C-G displayed differentiated sensitivity to multiple proteins, which was benefit from pillar[5]arene assisted the probe to form complexes with proteins. 4C-G could not only be applied in imaging of HepG2, but also act as a favorable drug carrier for regorafenib (REG) encapsulation. The 4C-G-REG complex would aggregate into high drug-loading fluorescent nanoparticles in a physiological environment (pH 7.4). Such nanoparticles exhibited pH-triggered enrichment ability, which rapidly enriched REG in the acidic environment (pH 6.0). Furthermore, the complexation between 4C-G and REG maintained the imaging property of the probe and the excellent anticancer activity of the drug on HepG2.