Nanotechnology-based drug delivery systems offer an unprecedented opportunity for tumor targeting. Nanocrystals are carrier-free crystalline nanosized solid drug particles. Due to high drug loading (as high as 100%), and being free of organic solvents or surfactants or polymers or solubilizing chemicals, nanocrystals have attracted great attention in the field of drug delivery for treatment of various cancers. Additionally, the hybrid or multifunctional nanocrystal has been extensively investigated for applications in experimental as well as clinical settings to improve delivery efficiency of therapeutic and diagnostic agents. This review gives an overview of recent advances and current status of nanocrystals, especially with respect to the method of preparations, physicochemical characterizations, in vitro/in vivo performance, scale-up techniques and applications in the field of drug delivery for different tumor targeting. Recently much attention has been given to multifunctional nanocrystals showing the capability to codeliver multiple components that target the drug delivery by surface functionalization, performing therapy as well as diagnosis. Preparative techniques like high-pressure homogenization, precipitation, and media milling have been known to show large-scale production of nanocrystals. High therapeutic applications of nanoparticles enable its administration through various routes like oral, parenteral, pulmonary, dermal, and ocular. Along with preparation and characterization, this review will dwell on the progress involved with multifunctional nanocrystals for cancer therapy and theranostics. Most available results in multifunctional nanocrystal targeting rely upon in vitro and animal models, which do not match the actual environment of the tumor in the body, which is one of the major obstacles. Other challenges faced when it comes to nanocrystals are scale-up and reproducibility. In addition, potential problems and possible future research directions for the advancement of newer techniques of multifunctional nanocrystals that make them highly suitable for tumor targeted are highlighted in this review.

Multifunctional nanocrystals for cancer therapy: a potential nanocarrier

This paper presents the influence of selected methodological aspects on the results of particlesize distribution (PSD) as measured by the laser diffraction method (LDM). The investigations were carried out using the Mastersizer 2000 with Hydro MU attachment (Malvern Ltd., UK). It was found that for the investigated soils: (1) optimal speed of pump and stirrer was 2500 rpm, (2) optimal measurement time was ≈ 1 min, (3) there are two, practically equivalent methods for soil-sample dispersion: chemical (with the use of a solution of sodium hexametaphosphate) or physical (by means of ultrasound application for 4 min at a maximum power of 35W), (4) one must not use the chemical and physical dispersing methods simultaneously, because this can lead to aggregation (not dispersion) of soil particles, (5) the Fraunhofer theory (physical models) can be used to convert scattered-light data to PSD. In the case of the Mie theory, the best results were obtained for a refractive index (RI) in the range of 1.5–1.6 and an absorption index (AI) of 1.0. It was also found that most of the discussed parameters depend on design of the measuring device and on the type and volume of the investigated suspensions. It is necessary, therefore, to explain how the data was obtained every time and to specify the details in the methodological part of the paper.

Methodological aspects of determining soil particle-size distribution using the laser diffraction method.

. Agricultural dust emissions have been estimated to contribute around 20% to the global dust burden. In contrast to dusts from arid source regions, the ice-nucleating abilities of which have been relatively well studied, soil dusts from fertile sources often contain a substantial fraction of organic matter. Using an experimental methodology which is sensitive to a wide range of ice nucleation efficiencies, we have characterised the immersion mode ice-nucleating activities of dusts (d

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Ice nucleation by fertile soil dusts: relative importance of mineral and biogenic components

Fine sediment and nutrient dynamics related to particle size and floc formation in a Burdekin River flood plume, Australia.

Comparative phytotoxicity of ZnO NPs, bulk ZnO, and ionic zinc onto the alfalfa plants symbiotically associated with Sinorhizobium meliloti in soil.

In this paper, we present results from a large number of experiments aimed at quantifying method and instrument uncertainty associated with laser diffraction analysis. We analyzed the size distribution of fine-grained sediment ( 24 hours prior to analysis and using 60 seconds of ultrasonication during analysis. (2) Obscuration--a measure of the concentration of the suspension during analysis--produced the most reproducible results at about 20%. (3) Variations in refractive-index settings can significantly alter estimated grain-size distributions. (4) Assumed values for absorption (the degree to which sediment grains absorb the light) can have a profound effect on grain-size results. Absorption settings near 0 resulted in unexpected bimodal grain size distributions for sediments in the < 10 µm size fraction and significantly skewed the fine-grained tail of coarser samples, probably because of sub-optimal diffraction by particles with a diameter similar in size to the laser wavelength. Absorption settings closer to 1 produced very reproducible results and unimodal grain-size distributions over a wide range of refractive indexes. Our study has shown that laser diffraction can measure very fine-grained sediments (< 10 µm) quickly, with high precision ( 5% at 2 standard deviations), and without the need for extensive mineralogical determinations. These results make possible a new generation of studies in which high-resolution time-series data sets of sediment grain size can be used to infer subtle changes in paleohydrology.

High-Resolution Particle Size Analysis of Naturally Occurring Very Fine-Grained Sediment Through Laser Diffractometry

Late Pleistocene and Holocene depositional history of sediments in Flathead Lake, Montana: Evidence from high-resolution seismic reflection interpretation

M. Sperazza

Papers

High-Resolution Particle Size Analysis of Naturally Occurring Very Fine-Grained Sediment Through Laser Diffractometry

Late Pleistocene and Holocene depositional history of sediments in Flathead Lake, Montana: Evidence from high-resolution seismic reflection interpretation

Sedimentary Indicators of Significant Late Pleistocene - Early Holocene Lake-Level Fluctuation: Preliminary Results From Flathead Lake, Montana

Neotectonic evolution and fault geometry change along a major extensional fault system in the Mission and Flathead Valleys, NW-Montana

Record of Late Pleistocene Through Holocene Climate Change in a Regional Lake System: Flathead Lake Basin, Northwestern Montana.