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Polymeric micelle nanocarriers in cancer research
Dae Hwan Shin, Yu Tong Tam, Glen S. Kwon
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 348-359.
https://doi.org/10.1007/s11705-016-1582-2
Amphiphilic block copolymers (ABCs) assemble into a spherical nanoscopic supramolecular core/shell nanostructure termed a polymeric micelle that has been widely researched as an injectable nanocarrier for poorly water-soluble anticancer agents. The aim of this review article is to update progress in the field of drug delivery towards clinical trials, highlighting advances in polymeric micelles used for drug solubilization, reduced off-target toxicity and tumor targeting by the enhanced permeability and retention (EPR) effect. Polymeric micelles vary in stability in blood and drug release rate, and accordingly play different but key roles in drug delivery. For intravenous (IV) infusion, polymeric micelles that disassemble in blood and rapidly release poorly water-soluble anticancer agent such as paclitaxel have been used for drug solubilization, safety and the distinct possibility of toxicity reduction relative to existing solubilizing agents, e.g., Cremophor EL. Stable polymeric micelles are long-circulating in blood and reduce distribution to non-target tissue, lowering off-target toxicity. Further, they participate in the EPR effect in murine tumor models. In summary, polymeric micelles act as injectable nanocarriers for poorly water-soluble anticancer agents, achieving reduced toxicity and targeting tumors by the EPR effect.
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Shape/size controlling syntheses, properties and applications of two-dimensional noble metal nanocrystals
Baozhen An,Mingjie Li,Jialin Wang,Chaoxu Li
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 360-382.
https://doi.org/10.1007/s11705-016-1576-0
Two dimensional (2D) nanocrystals of noble metals (e.g., Au, Ag, Pt) often have unique structural and environmental properties which make them useful for applications in electronics, optics, sensors and biomedicines. In recent years, there has been a focus on discovering the fundamental mechanisms which govern the synthesis of the diverse geometries of these 2D metal nanocrystals (e.g., shapes, thickness, and lateral sizes). This has resulted in being able to better control the properties of these 2D structures for specific applications. In this review, a brief historical survey of the intrinsic anisotropic properties and quantum size effects of 2D noble metal nanocrystals is given and then a summary of synthetic approaches to control their shapes and sizes is presented. The unique properties and fascinating applications of these nanocrystals are also discussed.
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Curcumin based combination therapy for anti-breast cancer: from in vitro drug screening to in vivo efficacy evaluation
Sunhui Chen,Qiuling Liang,Shuping Xie,Ergang Liu,Zhili Yu,Lu Sun,Meong Cheol Shin,Seung Jin Lee,Huining He,Victor C. Yang
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 383-388.
https://doi.org/10.1007/s11705-016-1574-2
While drug resistance appears to be an inevitable problem of an increasing number of anticancer drugs in monotherapy, combination drug therapy has become a prosperous method to reduce the administered total drug dosages as well as overcome the drug resistance of carcinoma cells. Curcumin, considered to possess multi-faceted roles in cancer treatment according to its multiple anti-neoplastic mechanisms as a depressor of chemo-resistance, can significantly facilitate its anti-cancer functions and improve therapeutic effects via combination usage with a variety of other drugs with different reaction mechanisms. To explore this possibility, four anti-cancer chemotherapeutic agents that all possess a certain degree of drug resistance problems, including three tyrosine kinase inhibitors (erlotinib, sunitinib and sorafenib) that are acting on different cell pathways and a typical anticancer drug doxorubicin, were combined with curcumin individually to examine the synergistic anti-tumor effect both in vitro and in vivo . Results revealed that sunitinib combined with curcumin at the molar ratio of 0.46 yielded the most potent synergistic effect in vitro , and was therefore chosen for further animal evaluation. To further enhance the anti-cancer effect, bovine serum albumin (BSA) nanoparticles were utilized as a carrier to deliver the selected drug combination in situ . Preliminary in vivo findings confirmed our hypothesis of being able to maintain a similar injected drug ratio for prolonged time periods in tested animals by our approach, thereby maximizing the therapeutic potency yet minimizing the toxicity of these drugs. This work could open up a new avenue on combination drug therapy and realization the clinical utility of such drugs.
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Inexpensive synthesis of a high-performance Fe3 O4 -SiO2 -TiO2 photocatalyst: Magnetic recovery and reuse
Nadir Abbas, Godlisten N. Shao, Syed M. Imran, Muhammad S. Haider, Hee Taik Kim
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 405-416.
https://doi.org/10.1007/s11705-016-1579-x
A sol-gel technique has been developed for the synthesis of a magnetite-silica-titania (Fe3 O4 -SiO2 -TiO2 ) tertiary nanocomposite with improved photocatalytic properties based on the use of inexpensive titania and silica precursors. The exceptional photocatalytic activity of the resulting materials was demonstrated by using them to photocatalyze the degradation of methylene blue solution. The best formulation achieved 98% methylene blue degradation. An interesting feature of the present work was the ability to magnetically separate and reuse the catalyst. The efficiency of the catalyst remained high during two reuses. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, ultra-violet-visible spectroscopy, diffuse reflectance spectroscopy, and thermogravimetric analysis. XRD analysis revealed the formation of multicrystalline systems of cubic magnetite and anatase titania crystals. SEM and TEM characterization revealed well-developed and homogeneously dispersed particles of size less than 15 nm. FTIR spectra confirmed the chemical interaction of titania and silica. It was further noticed that the optical properties of the prepared materials were dependent on the relative contents of their constituent metal oxides.
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Effect of thermal pretreatment on the surface structure of PtSn/SiO2 catalyst and its performance in acetic acid hydrogenation
Guozhen Xu, Jian Zhang, Shengping Wang, Yujun Zhao, Xinbin Ma
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 417-424.
https://doi.org/10.1007/s11705-016-1583-1
The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO2 catalyst in acetic acid (AcOH) hydrogenation was investigated in this article. The catalysts were characterized by N2 physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H2 -O2 titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSnx alloy was observed. Meanwhile, with the increment of thermal pretreatment temperature, Pt dispersion showed a decreasing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.
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Synthesis of a cardanol-amine derivative using an ionic liquid catalyst
Atanu Biswas, Carlucio R. Alves, Maria T. S. Trevisan, Roseane L. E. da Silva, Roselayne F. Furtado, Zengshe Liu, H. N. Cheng
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 425-431.
https://doi.org/10.1007/s11705-016-1581-3
Cardanol is a biobased raw material derived from cashew nut shell liquid. In order to extend its utility, new derivatives and additional applications are useful. In this work cardanol was first epoxidized, and a novel aniline derivative prepared from it under mild reaction conditions with the help of an ionic liquid catalyst. The reaction chemistry was studied by using nuclear magnetic resonance. The resulting aminohydrin adduct showed antioxidant property and should also be a useful synthon for further reactions. As an example, the aminohydrin was shown to undergo a condensation reaction with formaldehyde to form a prepolymer, which could be further reacted to form thermosetting resins.
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The formation and catalytic activity of silver nanoparticles in aqueous polyacrylate solutions
Jie Wang, Jianjia Liu, Xuhong Guo, Liang Yan, Stephen F. Lincoln
Front. Chem. Sci. Eng.. 2016, 10 (3 ): 432-439.
https://doi.org/10.1007/s11705-016-1584-0
Silver nanoparticles (AgNPs) have been synthesized in the presence of polyacrylate through the reduction of silver nitrate by sodium borohydride in aqueous solution. The AgNO3 and polyacrylate carboxylate group concentrations were kept constant at 2.0 × 10−4 and 1.0 × 10−2 mol?L−1 , respectively, while the ratio of [NaBH4 ]/[AgNO3 ] was varied from 1 to 100. The ultra-violet-visible plasmon resonance spectra of these solutions were found to vary with time prior to stabilizing after 27 d, consistent with changes of AgNP size and distribution within the polyacrylate ensemble occurring. These observations, together with transmission electron microscopic results, show this rearrangement to be greatest among the samples at the lower ratios of [NaBH4 ]/[AgNO3 ] used in the preparation, whereas those at the higher ratios showed a more even distribution of smaller AgNP. All ten of the AgNP samples, upon a one thousand-fold dilution, catalyze the reduction of 4-nitrophenol to 4-aminophenol in the temperature range 283.2–303.2 K with a substantial induction time being observed at the lower temperatures.
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