Drug-resistant bacterial infections exhibit a major threat to public health. Thus, exploring a novel antibacterial with efficient inhibition is urgently needed. Herein, this paper describes three ...types of MSNs (MSNs-FC2-R1, MSNs-FC2-R0.75, MSNs-FC2-R0.5) with controllable pore size (4-6 nm) and particle size (30-90 nm) that were successfully prepared. The MSNs were loaded with tetracycline hydrochloride (TCH) for effective inhibition of
(ATCC25922) and TCH-resistant
(MQ776). Results showed that the loading capacity of TCH in three types of MSNs was as high as over 500 mg/g, and the cumulative release was less than 33% in 60 h. The inhibitory rate of MSNs-FC2-R0.5 loaded with TCH against
and drug-resistant
reached 99.9% and 92.9% at the concentration of MIC, respectively, compared with the other two types of MSNs or free TCH. Modified MSNs in our study showed a great application for long-term bacterial growth inhibition.
Efficient and highly controllable antibacterial effects, as well as good biocompatibility, are required for antibacterial materials to overcome multi-drug resistance in bacteria. Herein, mesoporous ...silica nanomaterials (MSNs) carriers with a particle mean size of 60 nm and pore size of 7.9 nm were prepared, which was followed by loading with D-cysteine (D-Cys) and modified with Polyethyleneimine (PEI) molecules on the outer surface (named as D@MSNs-P). The prepared D@MSNs-P showed a good pH response in the range of 5–7, and the rate of antibacterial agent D-Cys released from nanocarriers was much faster at lower pH (pH 5) than that at higher pH (pH 6–7), which favors the rapid control of the pathogenic bacteria. In a working pH (pH 5), D@MSNs-P exhibited broad-spectrum antibacterial activities against Escherichia coli, Staphylococcus aureus, Salmonella enteritidis, and Listeria monocytogenes with the highest antibacterial efficiency of 99.9%, 99.8%, 98.1%, and 96.2%, respectively, which is much higher than that of pure D-Cys, pure MSNs, D@MSNs, and PEI group. The outstanding antibacterial activity of D@MSNs-P was attributed to the synergistic effect of the unique structure of MSNs and chiral D-Cys molecules. In addition, the prepared D@MSNs-P has no cytotoxicity to HepG2 cells (Human hepatoma cells) at the concentration of 0.4–12.8 mg/mL and even can promote cell proliferation at high concentrations. Our results open a new door for designing the most promising nanomaterials for pH response release and controllable antimicrobial.
•Mesoporous silica nanomaterials (MSN) with small size and big pore diameter was prepared.•Loading D-cysteine (D-Cys) and modified with PEI molecules on the surface (D@MSNs-P).•D@MSNs-P showed strong broad-spectrum antibiotic efficiency by damaging bacterial protein.•D@MSNs-P at high concentrations to HepG2 cells even can promote cell proliferation.
This study was designed to develop a cold plasma +222 nm ultraviolet (CP + UV) sterilization device in the food industry. Response surface methodology was applied to evaluate the effects of three ...treatment conditions on the antibacterial activity of CP + UV. The optimum treatment conditions (plasma gas flow: 4 m3/min, irradiation distance: 4 cm, treatment time: 60 s) were selected to optimize the reactor parameters of CP and 222 nm UV sterilization equipment, and its effects against the growth of S. aureus on different food contact materials were investigated. Results showed that the antibacterial activity against S. aureus was strongest when the plasma was operated at 8.5 kHz, 2.5 W/cm2 with two net layers of electrodes arranged transversely at a distance of 5 cm between the plasma outlet plane and UV centerline plane. After 60 s of CP + UV treatment, the number of S. aureus on the glass sheet, polypropylene film, corrugated paper, and kraft paper decreased by 4.5, 4.1, 1.5, and 2.4, respectively (p < 0.05). In summary, a novel CP + UV device was developed, which can be used for sterilization on different food surfaces, which potentially contributes to the development of the food industries.
•Combination of CP and UV treatment was used for sterilization.•Staphylococcus aureus on the glass sheet decreased by 5.40 Log CFU/cm2 after 60s treatment.•The order of sterilization was glass sheet > OPP film > kraft paper > corrugated paper.•A novel CP + UV device was developed to sterilize different food surfaces.
•Hyperspectral imaging technology coupled with chemometrics was used to distinguish the growth stage of molds on wheat grains.•The SVM model built with orthogonal signal correction treated full and ...characteristic wavelengths showed high accuracy.•The accuracy of SVM models built with characteristic wavelengths were from 72.67 % to 80.67 % for five molds.
Mildew on wheat is a undesired quality decrease process, producing a lot of toxic metabolites. In order to reduce economic loss and ensure the safety during wheat storage and transportation, the monitoring of mold growth in early stage is particularly important. This research was to study the different growth stages of five molds in wheat grains based on the hyperspectral imaging system. The visible-near-infrared hyperspectral information of wheat grains, with different molds growed from 1 day to 9 day, were collected to establish the model for the mold growth time discrimination. The spectroscopy in 50 wheat grains were collected for 9 days. Then, the SVM model was built with orthogonal signal correction (OSC) treated full-spectra for identification, with the coefficient of determination (R2 CV) ranged from 0.916 to 0.962, and from 0.507 to 0.748 for the root mean square error of cross-validation (RMSECV), from 0.940 to 0.964 for the determination coefficient of prediction (R2 P) and from 0.492 to 0.638 for the root mean error of prediction (RMSEP). In order to simplify the prediction models, successive projection algorithm (SPA) was employed to obtain the characteristic wavelengths. SVM models, which were better than PLS modes, were built by orthogonal signal correction (OSC)-treated characteristic wavelengths, R2 CV and RMSECV were 0.890–0.923 and 0.716–0.862 respectively, and R2 P and RMSEP of the models were 0.882–0.932 and 0.682–0.895 respectively. It can be concluded that hyperspectral imaging technology could be used to distinguish the growth time of different molds on wheat grains with high accuracy.
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