Theranostic platform, which is equipped with both diagnostic and therapeutic functions, is a promising approach in cancer treatment. From various nanotheranostics studied, iron oxide nanoparticles have advantages since IONPs have good biocompatibility and spatial imaging capability. This review is focused on the IONP-based nanotheranostics for cancer imaging and treatment. The most recent progress for applications of IONP nanotheranostics is summarized, which includes IONP-based diagnosis, magnetic resonance imaging (MRI), multimodal imaging, chemotherapy, hyperthermal therapy, photodynamic therapy, and gene delivery. Future perspectives and challenges are also outlined for the potential development of IONP based theranostics in clinical use.
Engineered nanomaterials and nanotechnologies promise many benefits to enhance both in vitro and in vivo performance. This is now manifest in the increasing number of reported biomedical products under development and testing that contain nanotechnologies as their distinguishing performance—enhancing components. In many cases, nano-sized materials are selected to provide a specific functional aspect that contributes to improved medical performance, either in vitro or in vivo. Nanoparticles are most commonly exploited in diverse roles in topical lotions and creams, solubilization aids, for in vitro and in vivo diagnostic and targeting agents in nanomedicines and theranostics. Despite fundamental scientific excitement and many claims to nanotechnology-based improvements in new biomedical applications, several fundamental and long-standing challenges remain to be addressed using nanomedicines to make clinically important progress. This review addresses several issues that must be fairly and objectively reported and then overcome to provide truly credible performance for nanomedicines.
The drug delivery scientists need to reexamine the advances made during the past 60 years, analyze our current abilities, and design the future technologies that will propel us to achieve the next level of drug delivery technologies. History shows that the first generation (1G) of drug delivery research during 1950–1980 was quite productive, while the second generation (2G) technologies developed during 1980–2010 were not as prolific. The ultimate goal of drug delivery research is to develop clinically useful formulations to treat various diseases. Effective drug delivery systems can be developed by overcoming formulation barriers and/or biological barriers. The engineering approach has a limit in solving the problem, if biological difficulties are not clearly identified and understood. The third generation (3G) drug delivery systems will have to focus on understanding the biological barriers so that they can be overcome by engineering manipulation of the drug delivery systems. Advances in the next 30 years will be most accelerated by starting open dialogues without any preconceived ideas on drug delivery technologies. The new generation of drug delivery scientists needs to be aware of the successes and limitations of the existing technologies to design the new technologies for meaningful advances in the future.
Catalytic fast pyrolysis (CFP) is deemed as the most promising way to convert biomass to transportation fuels or value added chemicals. Most works in literature so far have focused on the in situ CFP where the catalysts are packed or co-fed with the feedstock in the pyrolysis reactor. However, the ex situ CFP with catalysts separated from the pyrolyzer has attracted more and more attentions due to its unique advantages of individually optimizing the pyrolysis conditions and catalyst performances. This review compares the differences between the in situ and ex situ CFP operation, and summarizes the development and progress of ex situ CFP applications, including the rationale and performances of different catalysts, and the choices of suitable ex situ reactor systems. Due to the complex composition of bio-oil, no single approach was believed to be able to solve the problems completely among all those existing technologies. With the increased understanding of catalyst performances and reaction process, the recent trend toward an integration of biomass or bio-oil fractionation with subsequent thermo/bio-chemical conversion routes is also discussed.
The composite separator comprising of polysulfone and zirconia was prepared by phase inversion precipitation technique. The influence of manufacturing parameters on its properties was investigated, and the results show that the manufacturing parameters affect the ionic resistance and maximum pore size significantly. A modified composite separator with a support layer was prepared to enhance the tensile strength of separator. By adding support layer, the tensile strength of the separator increases from 1.85 MPa to 13.66 MPa. In order to evaluate the practical applicability of the composite separator, a small-scale industrial electrolytic experiment was conducted to investigate the changes of cell voltage, gas purity and separator stability. The results show that the modified composite separator has a smaller cell voltage and a higher H2 purity than the asbestos separator, and are promising material for industrial hydrogen production.
In this paper, a new kinetic model for methanol to olefin process over SAPO-34 catalyst was developed using elementary step level. The kinetic model fits well to the experimental data obtained in a fixed bed reactor. Using this kinetic model, the effect of the most important operating conditions such as temperature, pressure and methanol space-time on the product distribution has been examined. It is shown that the temperature ranges between 400 °C and 450 °C is appropriate for propene production while the medium temperature (450 °C) is favorable for total olefin yield which is equal to 33%. Increasing the reactor pressure decreases the ethylene yield, while medium pressure is favorable for the propylene yield. The result shows that the ethylene and propylene and consequently the yield of total olefins increase to approximately 35% with decreasing the molar ratio of inlet water to methanol.
The ternary phase diagrams of polyetherimide (PEI)/N,N-dimethylacetamide (DMAc) with H2O and BuOH as non-solvent were simulated using solubility parameter and Flory-Huggins theory. The phase diagrams show that 5.5% H2O/BuOH system containing 5% BuOH and 0.5% H2O, or 6.5% H2O/BuOH system containing 6.2% BuOH and 0.3% H2O is required to induce liquid-liquid demixing for 20 wt-% PEI/DMAc casting solution. Therefore, BuOH can enhance the phase separation of the PEI casting solution and hereby induce higher porosity of the membrane, and the diffusion of BuOH into the water coagulation bath causes larger pore size easily compared with DMAc. Our predictions that the membrane pure water flux first increases then decreases, and the rejection ratio of bovine serum albumin decreases with the increasing concentration of BuOH were validated by the experiments using the prepared membranes.
In this work, the effect of baffles in a pipe on heat transfer enhancement was studied using computational fluid dynamics (CFD) in the presence of Al2O3 nanoparticles which are dispersed into water. Fluid flow through the horizontal tube with uniform heat flux was simulated numerically and three dimensional governing partial differential equations were solved. To find an accurate model for CFD simulations, the results obtained by the single phase were compared with those obtained by three different multiphase models including Eulerian, mixture and volume of fluid (VOF) at Reynolds numbers in range of 600 to 3000, and two different nanoparticle concentrations (1% and 1.6%). It was found that multiphase models could better predict the heat transfer in nanofluids. The effect of baffles on heat transfer of nanofluid flow was also investigated through a baffled geometry. The numerical results show that at Reynolds numbers in the range of 600 to 2100, the heat transfer of nanofluid flowing in the geometry without baffle is greater than that of water flowing through a tube with baffle, whereas the difference between these effects (nanofluid and baffle) decreases with increasing the Reynolds number. At higher Reynolds numbers (2100–3000) the baffle has a greater effect on heat transfer enhancement than the nanofluid.
The putrefaction of alkaline silica sol was investigated in this paper. The total colony numbers in three alkaline silica sol samples were 1.47×105, 1.25×104, and 9.45×104 cfu·mL–1, respectively. The salt- and alkali-tolerant strains were isolated and selected using nutrient agar medium at 2.5% salinity and pH 9.5. Basic morphological, physiological and biochemical tests were conducted to confirm the preliminary characterizations of the strains. Based on API 50 CH test and 16S rDNA gene sequence analysis, the isolated strains were finally identified as Exiguobacterium aurantiacum, Cyclobacteriaceae bacterium, Microbacterium sp., Acinetobacter sp., Stenotrophomonas maltophilia and Bacillus thuringiensis. The survivability of the strains under different conditions such as salinities, acidities and temperatures was also studied. Some suitable methods for degerming, such as product pipe steam sterilization and regular canister cleaning, were proposed. To explore the possibility of isolates in industrial application, their alkaline protease and amylase production abilities were preliminarily studied. Five strains produced alkaline protease, whereas two strains produced alkaline amylase. Thus, understanding of the putrefaction on alkaline silica sol would be beneficial for improving industrial production.
A CuAlCl4 doped metal organic framework, CuAlCl4@MIL-101, was prepared by introducing CuAlCl4 into the pores of MIL-101 for the selective adsorption of CO over N2. The CuAlCl4 molecules were evenly distributed into various pores sizes and did not change the intrinsic structure of the MIL-101. Isotherms for CO and N2 adsorption at 298 K showed that the CO capacity on CuAlCl4@MIL-101 was much higher than that on virgin MIL-101, whereas the N2 capacity decreased. The selectivity for CO over N2 improved from 4.64 to 31.5 at 298 K and 1 bar. The CuAlCl4@MIL-101 adsorbent displayed outstanding CO adsorption stability and the adsorbent could be regenerated by applying a simple vacuum of 4 mmHg.
Increasing production effeciency and lowering costs are some of the many advantages melt crystallization technology offers over the conventional methodology of tabletting. A normal tablet consists of a pure shell or a coat and a separate core constituting the pharmaceutical active ingredient. Great emphasis is put on the purity of the shell since its purpose is to solely protect and deliver the active ingredient to its target. Melt crystallization is a purification (separation) process. It is discussed here for its ability to produce coated tablets, by separating the “coating” material from the “to be coated” material coming from one molten mixture. Molten drops of lutrol-ibuprofen mixture are produced using the drop forming technique. The subsequent analysis involves proving and quantifying the phase separation (coat purity). The mechanism of a crystallizing drop is shown as direct evidence of the ongoing process. Moreover, solidified tablet batches are analyzed for the purity of their coating by measuring the ibuprofen concentration. This optimization process is carried out through multiple stages of development and condition enhancements in order to produce the most pure tablet coating. As a result, a trial showing an almost purely coated tablet is presented here.
Mesoporous silica particles were prepared for efficient immobilization of the β-glucuronidase (GUS) through a biomimetic mineralization process, in which the solution containing lysozyme and GUS were added into the prehydrolyzed tetraethoxysilane (TEOS) solution. The silica particles were formed in a way of biomineralization under the catalysis of lysozyme and GUS was immobilized into the silica particles simultaneously during the precipitation process. The average diameter of the silica particles is about 200 nm with a pore size of about 4 nm. All the enzyme molecules are tightly entrapped inside the biosilica nanoparticles without any leaching even under a high ionic strength condition. The immobilized GUS exhibits significantly higher thermal and pH stability as well as the storage and recycling stability compared with GUS in free form. No loss in the enzyme activity of the immobilized GUS was found after 30-day’s storage, and the initial activity could be well retained after 12 repeated cycles.
A methodology to develop multi-component drugs based on traditional Chinese medicines has been developed using central composite design. Several active components from the traditional Chinese medicine turmeric were chosen for use in a multi-component antitumor drug. Response surface methodology based on a central composite design was applied to determine the quantitative composition-activity relationships in order to optimize the amount of each component in the drug. An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to measure the pharmacological activity as the response value. The experimental antitumor activity of the optimum combination was 92.85% in the MTT assay and superior to the activities of each single component. These results demonstrate that response surface methodology based on a central composite design is suitable for the design of multi-component drugs.
Catalysts Pt/TiO2 and NiMo/Al2O3 are highly active and selective for the hydrodeoxygenation of guaiacol in a fixed bed reactor at 300 °C and 7.1 MPa, leading to the hydrogenation of aromatic ring, followed by demethylation and dehydroxylation to produce cyclohexane. For a complete hydrodeoxygenation of guaiacol, metal sites and acid sites are required. NiMo/Al2O3 and Pt/Al2O3 are more active and selective for cyclohexane formation as compared with Pt/TiO2 at 285 °C and 4 MPa. However, Pt/TiO2 is stable while the other two catalysts deactivate due to the nature and amount of coke formation during the reaction.
Two types of polymeric surfactants, PEG300 and PVP40000 , were used for the preparation of magnetic ferrite MFe2O4 (M= Mn, Fe) colloidal nanocrystals using a solvothermal reaction method. The effect of spinel type effect on the size evolution of various nanoparticles was investigated. It was found that Fe3O4 nanoparticles exhibited higher crystalinity and size evolution than MnFe2O4 nanoparticles with use of the two surfactants. It is proposed that this observation is due to fewer tendencies of surfactants on the surface of Fe3O4 building blocks nanoparticles than MnFe2O4. Less amounts of surfactant or capping agent on the surface of nanoparticles lead to the higher crystalibity and larger size. It is also suggested that the type of spinel (normal or inverted spinel) plays a key role on the affinity of the polymeric surfactant on the surface of building blocks.