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排序方式: 共有749条查询结果,搜索用时 312 毫秒
741.
Maria Minodora Marin Raluca Ianchis Rebeca Leu Alexa Ioana Catalina Gifu Madalina Georgiana Albu Kaya Diana Iulia Savu Roxana Cristina Popescu Elvira Alexandrescu Claudia Mihaela Ninciuleanu Silviu Preda Madalina Ignat Roxana Constantinescu Horia Iovu 《International journal of molecular sciences》2022,23(1)
The fabrication of collagen-based biomaterials for skin regeneration offers various challenges for tissue engineers. The purpose of this study was to obtain a novel series of composite biomaterials based on collagen and several types of clays. In order to investigate the influence of clay type on drug release behavior, the obtained collagen-based composite materials were further loaded with gentamicin. Physiochemical and biological analyses were performed to analyze the obtained nanocomposite materials after nanoclay embedding. Infrared spectra confirmed the inclusion of clay in the collagen polymeric matrix without any denaturation of triple helical conformation. All the composite samples revealed a slight change in the 2-theta values pointing toward a homogenous distribution of clay layers inside the collagen matrix with the obtaining of mainly intercalated collagen-clay structures, according X-ray diffraction analyses. The porosity of collagen/clay composite biomaterials varied depending on clay nanoparticles sort. Thermo-mechanical analyses indicated enhanced thermal and mechanical features for collagen composites as compared with neat type II collagen matrix. Biodegradation findings were supported by swelling studies, which indicated a more crosslinked structure due additional H bonding brought on by nanoclays. The biology tests demonstrated the influence of clay type on cellular viability but also on the antimicrobial behavior of composite scaffolds. All nanocomposite samples presented a delayed gentamicin release when compared with the collagen-gentamicin sample. The obtained results highlighted the importance of clay type selection as this affects the performances of the collagen-based composites as promising biomaterials for future applications in the biomedical field. 相似文献
742.
A new technique, based on steady-state fluorescence measurements, is introduced for studying dissolution of polymer films. These films are formed from naphthalene and pyrene labeled poly(methyl methacrylate) (PMMA) latex particles, sterically stabilized by polyisobutylene. Diffusion of solvent (chloroform) into the annealed latex film was followed by desorption of polymer chains. Annealing was performed above Tg at various temperatures for 30-min time intervals. Desorption of pyrene labeled PMMA chains was monitored in real time by the pyrene fluorescence intensity change. Desorption coefficients were found to be between 1 and 4 × 10−10 cm2/s and two different dissolution mechanisms were detected. © 1996 John Wiley & Sons, Inc. 相似文献
743.
Moisture adsorption isotherms of commercial tarhana powder, a popular Turkish food used in soup making, were determined at 10 °C, 20 °C and 30 °C. Gravimetric static method was applied at 0.08–0.92 water activity range. The data was fitted to Guggenheim-Anderson-deBoer(GAB), Oswin, Hendersonand Brunauer-Emmett-Teller(BET)equations. Mean relative deviation (%E) was used to compare the goodness of fit. The BET was found the best equation for the range of water activity 0.08–0.58. The GAB equation was found adequate and gave similar result with the Oswinequation at 10 °C and 20 °C, while the Oswinequation was better for characterizing the adsorption behavior of tarhana sample for the whole range of temperature and water activity studied. 相似文献
744.
745.
Konstantin P. Katin Alexey I. Kochaev Savas Kaya Fadoua El-Hajjaji Mikhail M. Maslov 《International journal of molecular sciences》2022,23(4)
We theoretically investigated the adsorption of two common anti-COVID drugs, favipiravir and chloroquine, on fluorinated C60 fullerene, decorated with metal ions Cr3+, Fe2+, Fe3+, Ni2+. We focused on the effect of fluoridation on the interaction of fullerene with metal ions and drugs in an aqueous solution. We considered three model systems, C60, C60F2 and C60F48, and represented pristine, low-fluorinated and high-fluorinated fullerenes, respectively. Adsorption energies, deformation of fullerene and drug molecules, frontier molecular orbitals and vibrational spectra were investigated in detail. We found that different drugs and different ions interacted differently with fluorinated fullerenes. Cr3+ and Fe2+ ions lead to the defluorination of low-fluorinated fullerenes. Favipiravir also leads to their defluorination with the formation of HF molecules. Therefore, fluorinated fullerenes are not suitable for the delivery of favipiravir and similar drugs molecules. In contrast, we found that fluorine enhances the adsorption of Ni2+ and Fe3+ ions on fullerene and their activity to chloroquine. Ni2+-decorated fluorinated fullerenes were found to be stable and suitable carriers for the loading of chloroquine. Clear shifts of infrared, ultraviolet and visible spectra can provide control over the loading of chloroquine on Ni2+-doped fluorinated fullerenes. 相似文献
746.
747.
748.
Sumeyye Cesur Elif Ilhan Esra Pilavci Rabia Betul Sulutas Merve Gurboga Ozlem Bingol Ozakpinar Elif Kaya Marcin Heljak Gulgun Bosgelmez Tinaz Faik Nuzhet Oktar Oguzhan Gunduz Ewa Kijeńska-Gawrońska 《大分子材料与工程》2023,308(5):2200697
Corneal ulcer, which is brought on by a breach in the epithelial barrier, is a dangerous infection of the avascular corneal stroma. New treatment strategies are needed, suppressing the aggressive nature of the disease and including a combination of different drugs. In this study, vancomycin (VAN) and fluconazole (FLU) dual-drug loaded dual-layered polyvinyl alcohol and gelatin (PVA/GEL) nanofibrous patches are produced by electrospinning. Scanning electron microscopy (SEM) images show smooth surfaces are obtained for both pure and drug-loaded nanofibrous patches. The tensile test results report that loading the FLU and VAN separately into the PVA/GEL patches decrease both the tensile strength and elongation at break and it is further reduced when combining two drug-loaded layers in one patch. According to drug release results, the FLU and VAN-loaded nanofibrous patches show a controlled release profile extending up to 96 h. Moreover, PVA/GEL/FLU, PVA/GEL/VAN, and PVA/GEL/FLU/VAN nanofibrous patches display significant antimicrobial activity against Candida albicans and Staphylococcus aureus. SEM, 4'-6diamidynofenyloindol (DAPI) staining, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay show that PVA/FLU and PVA/GEL/FLU/VAN nanofibrous patches have a superior effect on NIH3T3 cell spreading and proliferation. The novelty of this study lays in the development of a potential dual drug rapid treatment for corneal ulcers of aggressive nature. 相似文献
749.
Debayan Chaudhury Ella R. Torkelson Kaya A. Meyers Dr. Justin F. Acheson Leta Landucci Yucen Pu Zimou Sun Dr. Marco Tonelli Dr. Craig A. Bingman Dr. Rebecca A. Smith Dr. Steven D. Karlen Dr. Shawn D. Mansfield Dr. John Ralph Dr. Brian G. Fox 《Chembiochem : a European journal of chemical biology》2023,24(9):e202300001
Chemically labile ester linkages can be introduced into lignin by incorporation of monolignol conjugates, which are synthesized in planta by acyltransferases that use a coenzyme A (CoA) thioester donor and a nucleophilic monolignol alcohol acceptor. The presence of these esters facilitates processing and aids in the valorization of renewable biomass feedstocks. However, the effectiveness of this strategy is potentially limited by the low steady-state levels of aromatic acid thioester donors in plants. As part of an effort to overcome this, aromatic acid CoA ligases involved in microbial aromatic degradation were identified and screened against a broad panel of substituted cinnamic and benzoic acids involved in plant lignification. Functional fingerprinting of this ligase library identified four robust, highly active enzymes capable of facile, rapid, and high-yield synthesis of aromatic acid CoA thioesters under mild aqueous reaction conditions mimicking in planta activity. 相似文献