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91.
Veronika Kozlovskaya Yiming Yang Fei Liu Kevin Ingle Aftab Ahmad Ganesh V. Halade Eugenia Kharlampieva 《Molecules (Basel, Switzerland)》2022,27(11)
Limited tissue selectivity and targeting of anticancer therapeutics in systemic administration can produce harmful side effects in the body. Various polymer nano-vehicles have been developed to encapsulate therapeutics and prevent premature drug release. Dually responsive polymeric vesicles (polymersomes) assembled from temperature-/pH-sensitive block copolymers are particularly interesting for the delivery of encapsulated therapeutics to targeted tumors and inflamed tissues. We have previously demonstrated that temperature-responsive poly(N-vinylcaprolactam) (PVCL)-b-poly(dimethylsiloxane) (PDMS)-b-PVCL polymersomes exhibit high loading efficiency of anticancer therapeutics in physiological conditions. However, the in-vivo toxicity of these polymersomes as biocompatible materials has not yet been explored. Nevertheless, developing an advanced therapeutic nanocarrier must provide the knowledge of possible risks from the material’s toxicity to support its future clinical research in humans. Herein, we studied pH-induced degradation of PVCL10-b-PDMS65-b-PVCL10 vesicles in-situ and their dually (pH- and temperature-) responsive release of the anticancer drug, doxorubicin, using NMR, DLS, TEM, and absorbance spectroscopy. The toxic potential of the polymersomes was evaluated in-vivo by intravenous injection (40 mg kg−1 single dose) of PVCL10-PDMS65-PVCL10 vesicles to mice. The sub-acute toxicity study (14 days) included gravimetric, histological, and hematological analyses and provided evidence for good biocompatibility and non-toxicity of the biomaterial. These results show the potential of these vesicles to be used in clinical research. 相似文献
92.
Ana Brăileanu Susana Mihaiu Margit Bán J. Madarász G. Pokol 《Journal of Thermal Analysis and Calorimetry》2005,80(3):613-618
Summary Oxide materials belonging to the Sn-Ce-O system are very interesting due to their use as solid electrolytes in fuel cells, catalysts, sensors and photoanodes in solar cells. The aim of the present work is to investigate the thermal behaviour of some tin and cerium salt mixtures. Mixtures with different representative Sn:Ce atomic ratio were prepared by classical ceramic method using SnC2O4, Ce(SO4)2·4H2O and (NH4)2Ce(NO3)6 as starting compounds. The samples were investigated by means of TG/DTA methods in flowing and static air atmosphere. SnO2 and/or CeO2 were identified by X-ray diffraction and IR spectroscopy in the final decomposition products, depending on the initial composition of the both series. A different crystallinity degree of the solid products was observed depending on the Ce precursor. 相似文献
93.
Pastor E Matveeva E Valle-Gallego A Goycoolea FM Garcia-Fuentes M 《Colloids and surfaces. B, Biointerfaces》2011,88(2):601-609
Mesoporous silicon is a biocompatible, biodegradable material that is receiving increased attention for pharmaceutical applications due to its extensive specific surface. This feature enables to load a variety of drugs in mesoporous silicon devices by simple adsorption-based procedures. In this work, we have addressed the fabrication and characterization of two new mesoporous silicon devices prepared by electrochemistry and intended for protein delivery, namely: (i) mesoporous silicon microparticles and (ii) chitosan-coated mesoporous silicon microparticles. Both carriers were investigated for their capacity to load a therapeutic protein (insulin) and a model antigen (bovine serum albumin) by adsorption. Our results show that mesoporous silicon microparticles prepared by electrochemical methods present moderate affinity for insulin and high affinity for albumin. However, mesoporous silicon presents an extensive capacity to load both proteins, leading to systems were protein could represent the major mass fraction of the formulation. The possibility to form a chitosan coating on the microparticles surface was confirmed both qualitatively by atomic force microscopy and quantitatively by a colorimetric method. Mesoporous silicon microparticles with mean pore size of 35 nm released the loaded insulin quickly, but not instantaneously. This profile could be slowed to a certain extent by the chitosan coating modification. With their high protein loading, their capacity to provide a controlled release of insulin over a period of 60-90 min, and the potential mucoadhesive effect of the chitosan coating, these composite devices comprise several features that render them interesting candidates as transmucosal protein delivery systems. 相似文献
94.
We present density functional theory calculations for atomic hydrogen interacting with a stepped surface, the Pt(211) surface. The calculations have been performed at the generalized gradient approximation level, using a slab representation of the surface. This is the state-of-the-art method for calculating the interaction of atoms or molecules with metal surfaces, nevertheless only few studies have used it to study atoms or molecules interacting with stepped surfaces, and none, to the best of our knowledge, have considered hydrogen interacting with stepped platinum surfaces. Our goal has been to initiate a systematic study of this topic. We have calculated the full three-dimensional potential energy surface (PES) for the H/Pt(211) system together with the vibrational band structure and vibrational eigenfunctions of H. A deep global minimum of the PES is found for bridge-bonded hydrogen on the step edge, in agreement with experimental results for the similar H/Pt(533) system. All the local vibrational excitations at the global minimum have been identified, and this will serve as a helpful guide to the interpretation of future experiments on this (or similar) system(s). Furthermore, from the calculated PES and vibrational band structure, we identify a number of consequences for the interpretation or modelling of diffusion experiments studying the coverage and directional dependence of atomic hydrogen diffusion on stepped platinum surfaces. 相似文献
95.
Gabriela Iacobescu Adrian Liviu Păun Cristina Cârtoaje 《Journal of magnetism and magnetic materials》2008
A static and dynamic investigation was performed on liquid crystal cells containing pure nematics and nematics doped with an azo-dye (Methyl Orange). It was found that the critical field for magnetic Freedericksz transition was decreased in samples containing the “trans” isomer and increased in those containing the “cis ” isomer. Changes in the relaxation time τA, τB intervening when switching on/off the magnetic field were also noticed. A theoretical model was elaborated to explain these phenomena. 相似文献
96.
97.
In the present paper we answer two questions raised by Barbilian in 1960. First, we study how far can the hypothesis of Barbilian’s
metrization procedure can be relaxed. Then, we prove that Barbilian’s metrization procedure in the plane generates either
Riemannian metrics or Lagrance generalized metrics not reducible to Finslerian or Langrangian metrics. 相似文献
98.
M. Ionescu-Bujor A. Iordăchescu E. A. Ivanov G. Pascovici D. Ploştinaru V. Sabaiduc 《Zeitschrift für Physik A Hadrons and Nuclei》1990,336(3):291-296
The two short-lived isomeric states in112In have been reinvestigated by means of the112Cd(d, 2n) and109Ag (α, n) reactions. Measurements of delayed X- andγ-ray, lifetime and TDPAD spectra have been performed. A 6.32(3) keVγ-ray has been identified in the isomeric decay and anM1 multipolarity has been assigned to it on the basis of the measured internal conversion coefficients:α L =196(39) andα tot=231(35). TheE1+M2(δ =+0.24(4)) andE2 multipolarities have been determined for the 263 and 188 keV transitions deexciting the 8?(T 1/2=2.82(2) μs) and 7+ (T 1/2=0.93(2) μs) isomeric states, respectively. A revised isomeric decay scheme is presented. 相似文献
99.
S. Dumitriu M. I. Popa I. Hăulică A. Crîngu A. Stratone 《Colloid and polymer science》1989,267(7):595-599
Ampicillin and chloramphenicol were coupled on xanthan by activation by dicyclohexyl-carbodiimide. Drug release from the support was studied in vitro for ampicillin, and in vitro and in vivo conditions for chloramphenicol. 相似文献
100.
Ecaterina Matei Claudia Drăgan Cristian Pantilimon Cristian Predescu 《Analytical letters》2017,50(17):2822-2838
ABSTRACTTwo nanostructured hybrid materials are reported that include uncoated magnetic nanoiron oxides and magnetic nanoiron oxides treated with rose leaf extract. Atomic and molecular absorption spectrometry were used to evaluate the sensitivity of these materials for the isolation of Cr(VI), Zn(II), Pb(II), and Ca(II) from aqueous solution. The structure and physicochemical properties of the resulting nanohybrids were characterized by scanning electron microscopy coupled with energy-dispersive spectroscopy, atomic force microscopy, and X-ray diffraction. The results show that following 15?min of contact in acidic solution, the uncoated magnetic nanoiron oxides removed approximately 90% of Cr(VI), while the magnetic nanoiron oxides coated with rose leaf extract removed 92% of the analyte. These correspond to most industrial wastewater conditions. For the removal of Ca(II) and Zn(II), it was necessary to adjust the pH to neutral to maximize the efficiency. Pb(II) showed maximum removal efficiency when the solution is basic. The simple rose extract suspension was also used for metal removal with high capacity. The results demonstrate that the magnetic nanoiron oxides were uniformly distributed in the rose leaf extract. The extract served as a capping agent due to the presence of polyphenolics. 相似文献