Search

This experiment was done to study the zeolite molecular sieve as a drug-binding effector, the non-antibiotic drug potassium diformate uniformly disperse in the internal aqueous phase of the 'egg box' structure formed by pectin-calcium ions. With oil phase as the intermediate phase and Xanthan gum Chitosan as the external water phase, the W/O/W type sustained release bacteriostatic microcapsules with pH response were prepared and characterized by Fourier transform infrared, thermogravimetric, SEM, and TEM. It can be obtained through characterization experiments that the inner water phase, oil phase, and outer water phase were formed by observation, and W/O/W emulsion microcapsules were obtained and the bacteriostasis effect of microcapsules was verified by bacteriostasis experiment. The permeance experiment showed that the molecular sieve was successfully coated in the microsphere. Studying on drug release mechanism and sustaining release performance of composite emulsion microcapsules. In vitro drug release study showed that the encapsulation efficiency and drug loading rate of microcapsules were improved by adding molecular sieve, reaching 12.31% and 61.55%, respectively. At the same time, we observed that the drug release rate slowed down during the simulated intestinal release process, and the drug release kinetics were in line with the first-order kinetic model and Ritger-Peppas model equation. Experiments had proven that the drug-loaded microcapsules exerted a significant bacteriostatic effect on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis, with the highest antibacterial rates of 97.25%, 94.05%, and 95.93%, respectively. Therefore, the composite emulsion microcapsules can be used as a new controlled-release drug delivery system in vivo. [ABSTRACT FROM AUTHOR]

As one of the raw materials of biodegradable food packaging, gelatin is an environmentally friendly substitute for traditional plastic packaging. In this review both sources and extraction methods of gelatin are introduced, together with recent modification methods and applications of using plant sources instead of synthetic substances to endow gelatin film with functionality. Gelatin is extracted from mammals, marine organisms, and poultry. Different extraction methods (acid, alkali, enzyme treatment) can affect the molecular weight and amino acid composition of gelatin, thus affecting the molecular structure, physical properties, chemical and functional properties of gelatin. Gelatin serves as a good substrate, but its disadvantage is that it is very brittle. However, the addition of plasticizers can improve the flexibility of the film by reducing chain interactions during the dehydration process. Compared with other plasticizers, glycerol and sorbitol have better effects on adjusting the mechanical properties of gelatin films. Gelatin is combined with active substances such as essential oils, plant extracts, and nanoparticles to prepare gelatin based composite films with good mechanical properties and antibacterial and antioxidant properties. Gelatin-based composite films can effectively inhibit the growth and reproduction of microorganisms and lipid oxidation in food. Applying it to food packaging can improve the quality of fresh food and extend its shelf life. [ABSTRACT FROM AUTHOR]

In the present study, ultrasound-assisted extraction was employed to extract the general flavone from celery leaves using response surface methodology and BP neural network model with a genetic algorithm (GA). The effects of temperature, time, solid-liquid ratio, and ethanol concentration on the extraction results were assessed by Box-Behnken design. Further optimization of the process was performed by GA-BP. Our results showed that the optimal conditions were an ethanol concentration of 70.31%, a temperature of 67.2 °C and an extraction time of 26.6 min. In addition, significant antioxidant activity and in vitro bacteriostasis were observed. We found that the total flavonoids of the celery leaves exerted a strong inhibitory effect on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. Additionally, considerable DPPH· and ·OH scavenging effects were exerted by flavonoids. Therefore, flavonoids from celery leaves can be considered natural antioxidants and bacterial inhibitors. [ABSTRACT FROM AUTHOR]

Implantable polyetheretherketone (PEEK) has great biomedical potential as hard tissue substitute in orthopedic application due to its outstanding mechanical properties and excellent biological stability. However, the poor osseointegration and bacteriostatic ability of implantable PEEK become the major barrier for its wide clinic application. In this study, a hierarchically micro/nano-topographic PEEK with specific functional groups (amino and COOH/COOR) has been fabricated using facile sulfonation combined with argon plasma treatment. The new developed hierarchically micro/nano-topographic PEEK have enhanced hydrophilicity, surface roughness, as well as the high ability of apatite-layer forming. Antibacterial assessment shows that as-treated samples exhibit better antibacterial activity. The cellular responses in osteoblast-like MG-63 cells culturing experiment reveal that the micro/nano-topography accompanied with specific functional groups improves the cell adhesion at the initial stage, further ameliorates proliferation and osteogenic differentiation of MG-63. This study proposes a promising approach to increase osteodifferentiation activity and bacteriostasis of PEEK via synergistic effects involving surface topologic structure and chemical modification, which shows great potential in developing advanced implantable materials. [ABSTRACT FROM AUTHOR]

A novel graphene oxide-balofloxacin nanocomposite was synthesized, and the loading and release behavior of fluorescent antibacterial balofloxacin on graphene oxide was investigated. The surface morphologies of the nanocomposite were evaluated using transmission electron microscopy and fluorescence microscopy, and the amount of balofloxacin loaded on graphene oxide reached 160.3 mg/g at the initial balofloxacin concentration of 8.51 µg/ml. The graphene oxide and balofloxacin nanocomposite showed the advantage of a longer release time than many current developed nanoscaled drug carriers, which was probably due to the hydrogen bonding interaction between graphene oxide and balofloxacin. The study of the release liquid ofe. coliin vitro bacteriostasis suggests that the graphene oxide-balofloxacin nanocomposite has a superior effect againste. coli. [ABSTRACT FROM AUTHOR]

N, N'-didodecyl-2-hydrxyl-N, N, N'N'-tetramethyl-dichloride has been synthesized with R (CH3)2N (R = CnH2n+1, n = 12, 14, 16), hydrogen chloride and epoxy chloropropane as raw materials. The products have been characterized by element analysis and 1H NMR spectra. Fundamental interfacial behavior of the surfactant at the air/water interface has been investigated by means of surface tension measurements to provide an insight into relationship between the structure of the hydrophobic moiety and the surfactant properties. Foam performance and bacteriostasis in aqueous solution have been investigated. The results indicate that the gemini cationic surfactants have strong surface activity. The surface activity is relevant to the number of carbon atoms in the hydrophobic tail of surfactant molecule. The longer the alkyl chain is, the stronger the surface activity and the lower the critical micelle concentration will be. G12Cl2 solution possesses the best performance of the foaming ability and foam stability at 298.15 K, but bubbly and stability efficiency is the lowest among the three systems. Bacteriostasis of the surfactants has been determined with disk diffusion on filter paper. The results show that all of the newly synthesized double quaternary ammoniums possess quite good bacteriostasis. [ABSTRACT FROM AUTHOR]

The relationship between the immunological activities and their surface activities of octadecanoyl acetal sodium sulphite series containing different numbers of double bonds (HOU-C18:n; n = 1, Δ9; n = 2, Δ9,12; n = 3, Δ9,12,15) were studied. The results showed that HOU-C18:n were able to increase the carbon granular clearance rate K, the NK cell activity in spleen and the activity of lysozymes in serum as well as inhibit Staphylococcus aureus and lysozymes in vitro to some degree. As the number of double bonds in HOU-C18:n increased along with the hydrophobic properties and the ability to improve the immune activity, NK cell activity and lysozyme activity decreased, but the bacteriostatic activity increased. It is speculated that HOU-C18:n could improve immunity and bacteriostasis realised by the interaction between the hydrophobic chain and membranes of cells. From the results of the effects of HOU-C18:n on lysozymes in vivo and in vitro, it is speculated that HOU-C18:0 could initiate and greatly enhance lysozyme activity in serum by increasing the amount of lysozymes, while unsaturated HOU-C18:n might do so mainly by increasing the number of lysozymes. [ABSTRACT FROM AUTHOR]

Based on the microbial model ( Staphylococcus aureus and Bacillus subtilis) and the experiment of mouse carbon granular clearance, the relationship between antibacterial and immunological activities of houttuyfonate (HOU) homologues and their surface activities were studied. The results showed that with elongating the carbon chain of HOU homologues, the surface activities and bacteriostasis and immunological activities would be increased. It is suggested that the pharmacological effect of HOU homologues could be realized by the hydrophobic interaction between HOU homologues and membrane proteins of bacteria and cell. [ABSTRACT FROM AUTHOR]