One limitation of current biodegradable polymeric nanoparticles is their inability to effectively encapsulate and sustainably release proteins while maintaining protein bioactivity. Here we report the engineering of PLGA–polycation nanoparticles with a core–shell structure that act as a robust vector for the encapsulation and delivery of proteins and peptides. The optimized nanoparticles can load high amounts of proteins (>20 % of nanoparticles by weight) in aqueous solution without organic solvents through electrostatic interactions by simple mixing, thereby forming nanospheres in seconds with diameters <200 nm. The relationship between nanosphere size, surface charge, PLGA–polycation composition, and protein loading is also investigated. The stable nanosphere complexes contain multiple PLGA–polycation nanoparticles, surrounded by large amounts of protein. This study highlights a novel strategy for the delivery of proteins and other relevant molecules. 相似文献
We have developed a gold ion-imprinted polymer (GIP) by incorporating a dipyridyl ligand into an ethylene glycol dimethacrylate matrix which then was coated onto porous silica particles. The material was used for the selective extraction of ultratrace quantities of gold ion from mine stones, this followed by its quantitation by FAAS. The effects of concentration and volume of eluent, pH of the solution, flow rates of sample and eluent, and effect of potentially interfering ions, especially palladium and platinum, was investigated. The limit of detection is <0.2 ng?mL?1, the precision (RSD%) is 1.03 %, and recoveries are >99 %. In order to show the high selectivity and efficiency of the new sorbent, the results were compared to those obtained with more simple sorbents possessing the same functional groups. The accuracy of the method was demonstrated by the accurate determination of gold ions in a certified reference material. To the best of our knowledge, there is no report so far on an imprint for gold ions that has such a selectivity over Pd(II) and Pt(II) ions.
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Coating of gold ion imprinted polymer on nanoporous silica 相似文献
Montmorillonite KSF and K10 clays catalyzed effectively the reaction of methyl diazoacetate with various aldehydes using microwave irradiation under solvent-free conditions affording the corresponding β-keto esters in good yields and short reaction time. The present method is an improvement for the previous known synthetic methods and has many obvious advantages compared to them including the high efficiency, generality, high yields, operational simplicity, environmental benignity, and possibility of recycling the natural solid clays. 相似文献
A highly stereoselective method for preparing ( Z)- and ( E)-enol triflates derived from substituted acetoacetate derivatives is described. The salient feature of this methodology is the use of Schotten-Baumann-type conditions to control enolate geometry using either aqueous LiOH ( Z-selective) or aqueous (Me)(4)NOH ( E-selective) in combination with triflic anhydride to provide a practical and predictable approach to these valuable substrates. 相似文献
Journal of Solid State Electrochemistry - Li7La3Zr2O12 (LLZO) is one of the most competent candidates as a solid electrolyte for next-generation Li-ion batteries. Although the stabilization of the... 相似文献
Membrane separator based on the polyvinylidene fluoride (PVDF) is prepared via the non-solvent-induced phase separation (NIPS) method with water and ethanol as non-solvent and a mixture of dimethylformamide (DMF) and acetone as solvent. The effect of various acetone/DMF ratios and non-solvent material on the physical and electrochemical properties of the separator is studied by FE-SEM, tensile strength, electrochemical AC-impedance spectroscopy (EIS), thermal stability, and linear sweep voltammetry (LSV). The charge-discharge studies are carried out by fabricating a lithium foil/polymer electrolyte membrane/LiFePO4 cell. The results show that with the change of solvent and non-solvent, the structure and morphology of the separator change and its physical and electrochemical properties. The results indicate that the membrane sample with non-solvent ethanol, acetone/DMF: 80/20 (wt/wt), and PVDF/PU: 95/5 (wt/wt) shows high porosity (66.3%) and high ionic conductivity (1.34 mS/cm) as well as excellent thermal stability.
Journal of Thermal Analysis and Calorimetry - In modern heat transfer systems, thermal storage not only causes the balance between demand and supply, but also improves the heat transfer efficiency... 相似文献
Over the past decade, there have been remarkable advances in understanding the signaling pathways involved in cancer development. It is well-established that cancer is caused by the dysregulation of cellular pathways involved in proliferation, cell cycle, apoptosis, cell metabolism, migration, cell polarity, and differentiation. Besides, growing evidence indicates that extracellular matrix signaling, cell surface proteoglycans, and angiogenesis can contribute to cancer development. Given the genetic instability and vast intra-tumoral heterogeneity revealed by the single-cell sequencing of tumoral cells, the current approaches cannot eliminate the mutating cancer cells. Besides, the polyclonal expansion of tumor-infiltrated lymphocytes in response to tumoral neoantigens cannot elicit anti-tumoral immune responses due to the immunosuppressive tumor microenvironment. Nevertheless, the data from the single-cell sequencing of immune cells can provide valuable insights regarding the expression of inhibitory immune checkpoints/related signaling factors in immune cells, which can be used to select immune checkpoint inhibitors and adjust their dosage. Indeed, the integration of the data obtained from the single-cell sequencing of immune cells with immune checkpoint inhibitors can increase the response rate of immune checkpoint inhibitors, decrease the immune-related adverse events, and facilitate tumoral cell elimination. This study aims to review key pathways involved in tumor development and shed light on single-cell sequencing. It also intends to address the shortcomings of immune checkpoint inhibitors, i.e., their varied response rates among cancer patients and increased risk of autoimmunity development, via applying the data from the single-cell sequencing of immune cells. 相似文献
In this work, we first consider the discrete version of Fisher information measure and then propose Jensen–Fisher information, to develop some associated results. Next, we consider Fisher information and Bayes–Fisher information measures for mixing parameter vector of a finite mixture probability mass function and establish some results. We provide some connections between these measures with some known informational measures such as chi-square divergence, Shannon entropy, Kullback–Leibler, Jeffreys and Jensen–Shannon divergences. 相似文献