Tween-80 improves single/coaxial electrospinning of three-layered bioartificial blood vessel.

Electrospinning is a promising technique for preparing bioartificial blood vessels. Nanofibers prepared by electrospinning can simulate the structure of extracellular matrix to promote cell adhesion and proliferation. However, thorn-like protrusions can appear as defects on electrospun scaffolds and coaxial electrospun nanofibers often have no clear core/shell structure, which can seriously affect the quality of bioartificial blood vessels. To address these problems, Tween 80 is added to the electrospinning solution, which results in a stable Taylor cone, eliminates the thorn-like protrusions on electrospun bioartificial blood vessels, and reduces interfacial effects due to different core/shell solutions during coaxial electrospinning. Simulations, biomechanical tests, and in vivo studies were performed. The results demonstrate the excellent mechanical properties and biocompatibility of the bioartificial blood vessel. This research provides a useful reference for optimizing the electrospinning process for fabricating bioartificial blood vessels.

Preparation of magnetic molecularly imprinted polymers for the identification of zearalenone in grains.

This study was based on the specific binding ability of magnetic molecularly imprinted polymers (MMIPs) combined with a high-performance liquid chromatography-fluorescence detector (HPLC-FLD) for the rapid determination of zearalenone (ZEN) in cereals. A novel magnetic molecularly imprinted polymer was prepared by surface imprinting technology. Warfarin was used as a virtual template, 3-aminopropyl triethoxysilane (APTES) was used as the functional monomer, and tetraethyl orthosilicate (TEOS) was used as the cross-linking agent. Analysis by a vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that MMIPs were prepared with a particle size about 450 nm, the imprinted molecular layer accounting for 10.7% of the total mass, and saturation magnetization of about 34.54 emu/g. The maximum adsorption capacity (Qmax) of the thermodynamic and kinetic adsorption experiments were 13.90 mg/g and 8.71 mg/g, respectively. The Langmuir model showed that the binding sites were uniformly distributed on the surface of the MMIPs. The Scatchard analysis showed that MMIPs had two types of binding sites with Qmax of 8.22 mg/g and 15.37 mg/g, respectively. In actual sample detection, the limit of detection (LOD) and limit of quantification (LOQ) were 0.4 ng/kg and 0.9 ng/kg, respectively. The sample recovery rate was 90.56-99.96%, the daytime stability was 1.35-2.87%. These results showed that MMIPs had good performance in selectively identifying ZEN and were suitable for determining ZEN in cereals.

Optimization on conditions of podophyllotoxin-loaded liposomes using response surface methodology and its activity on PC3 cells.

The purpose of this study was to optimize the preparation conditions of podophyllotoxin liposomes (PPT-Lips), and to investigate their effects on PC3 cells. PPT-Lips were prepared by using a thin-film dispersion method. In order to achieve maximum drug encapsulation efficiency (EE), the process and formulation variables were optimized by response surface methodology (RSM). The optimum preparation conditions were cholesterol to lecithin ratio of 3.6:40 (w/w), lipid to drug ratio of 15.8:1 (w/w), and the ultrasonic intensity of 35% (total power of 400 W). The experimental EE of PPT-Lips was 90.425%, which was consistent with the theoretically predicted value. The characterization studies showed that PPT-Lips were well-dispersible spherical particles with an average size of 106 nm and a zeta potential of -10.1 mV. A gradual and time-dependent pattern of PPT from liposomes was found in in vitro drug release with a cumulative release amount up to 70.3% in 24 h. Results of cell viability experiments on PC3 cells demonstrated that PPT-Lips exhibited more effective anticancer activity in comparison with free PPT. Therefore, PPT-Lips represent an efficient and promising drug delivery system for PPT.

Novel hydrocortisone magnetic molecularly imprinted polymers: Preparation, characterization, and application.

In this work, magnetic molecularly imprinted polymers (MMIPs) were prepared by a surface imprinting method using Fe3O4 nanoparticles as a support. The products were characterized by FT-IR spectroscopy, VSM, TGA, SEM, and TEM. Combined with HPLC, hydrocortisone in milk powder and milk were separated and purified, and their contents were monitored. The results showed that MMIPs with a particle size of approximately 1000 nm were successfully prepared. The adsorption mechanism of MMIPs was confirmed by kinetic adsorption and thermodynamic adsorption experiments; the maximum adsorption capacity was found to be 17.2 mg g-1, and adsorption equilibrium could be reached within 40 min. In the actual sample application, the recovery rates of milk powder and milk were 93.88-99.15% and 95.80-98.10%, respectively. These results showed that MMIPs had good performance in selectively identifying hydrocortisone and were suitable for determining hydrocortisone in milk products.

Preparation of a Novel Carbon Dot/Polyvinyl Alcohol Composite Film and Its Application in Food Preservation.

Carbon dots (CDs) were synthesized with the facile hydrothermal method to produce CDs/polyvinyl alcohol (PVA) active food packaging films. The CDs had a diameter ranging from 2.01 to 5.61 nm and were well-dispersed. The effects of different concentrations of CDs on mechanical strength, water resistance, morphology, optical, and thermal performance of the CDs/PVA films were discussed. The incorporation of CDs in the PVA film improved its mechanical properties, water resistance properties, UV blocking properties, and thermal stability and endowed the composite film with antioxidant and antimicrobial properties. The maximum scavenging rates of 2,2-diphenyl-1-picrylhydrazyl and ABTS free radicals by the 0.50% CDs/PVA film were 72.81 and 97.08%, respectively. The inhibition zone diameters of the 0.50% CDs/PVA solution against Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), and Escherichia coli (E. coli) were 9.52, 8.21, and 9.05 mm, respectively. Using the 0.50% CDs/PVA film as active packaging, the shelf life of banana, jujube, and fried meatballs was observed to be extended significantly. These results demonstrate the viability of the CDs/PVA composite film as a promising active food packaging material.

Preparation of magnetic molecularly imprinted polymer for selective identification of patulin in juice.

A highly efficient and selective method was successfully developed by using magnetic molecularly imprinted polymers (MMIPs) combined with high performance liquid chromatography (HPLC) to quickly determine patulin (PAT) in juice. MMIPs was prepared by surface imprinting method using Fe3O4 nanoparticles as supporter, 2-oxindole as virtual template, (3-Aminopropyl) triethoxysilane (APTES) as functional monomer and tetraethyl orthosilicate (TEOS) as crosslinking agent. The structure of the product was characterized by vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that MMIP with a particle size of about 450 nm was successfully prepared, the imprinted molecular layer accounted for about 11.6% of the total mass, and the saturation magnetization was about 6.82 emu/g. The maximum adsorption capacities (Qmax) of kinetic and thermodynamic adsorption experiments were 1.97 mg/g and 4.241 mg/g, respectively. The adsorption process was highly selective and fitted well with the pseudo-second-order model. Langmuir model demonstrated that the binding sites were evenly distributed on the surface of the MMIPs. Scatchard analysis showed that MMIPs had two types of binding sites with Qmax of 4.53 mg/g and 5.73 mg/g, respectively. In the actual sample application, the limit of detection (LOD) and the limit of quantification (LOQ) were 3 µg/kg and 10 µg/kg. And the recovery rate of the sample was 86.44-95.50%. MMIPs possessed excellent applicability with stability of 1.11-3.16% and accuracy of 0.63-1.94%. These results indicated that MMIPs had good performance in separating PAT and was suitable for determining PAT in actual samples.