Titania and Zinc Oxide Nanoparticles: Coating with Polydopamine and Encapsulation within Lecithin Liposomes—Water Treatment Analysis by Gel Filtration Chromatography with Fluorescence Detection

A Novel Centrifugal Filtration Device

In the proposed centrifugal filtration device, a filter is mounted in the center of the centrifugal chamber. The particles move towards the centrifuge wall away from the filter under centrifugal force, so a filtration cake is unlikely to accumulate here. The working fluid is injected continuously, so the feed pressure is higher than the discharge pressure, which compels the light-phase fluid to leave through the filter as filtrate. The filtrate flux rate and the movement of particles in the centrifugal chamber of the proposed filtration device were investigated using different powder particle sizes, concentrations of working fluid, centrifugal chamber rotation speeds, and filters. With a higher centrifugal chamber rotation speed, the centrifugal force acting on the particles in the centrifugal chamber was stronger, and the particles were less likely to adhere to the central filter; hence, a larger amount of filtrate was produced.

Facile preparation of liposome-encapsulated Zn–DTPA from soy lecithin for decorporation of radioactive actinides

Diethylenetriaminepentaacetic acid (DTPA) is an attractive decorporation agent that can enhance the excretion of radioactive actinides such as plutonium, americium, and curium after a radiological incident. However, DTPA is excreted in a short period of time after administration. Several formulations have been developed to improve DTPA pharmacokinetics properties. In this project, liposomes were prepared facilely from soy lecithin as a nanocarrier for pulmonary delivery of Zn–DTPA. Lipid hydration, reverse phase evaporation, and mechanical sonication were three methods evaluated for the preparation of liposome-encapsulated Zn-DTPA (lipo-Zn-DTPA). Mechanical sonication was the method of choice due to simple apparatus and facile preparation. Lipo-Zn–DTPA exhibited a hydrodynamic diameter of 178 ± 2 nm and a spherical shape. The loading capacity and encapsulation efficiency of Zn–DTPA were 41 ± 5 mg/g and 10% ± 1%, respectively. Lyophilization of lipo-Zn–DTPA for extended storage did not affect the amount of encapsulated drug or damage the structure of liposomes. An in vivo cytotoxicity test confirmed no serious adverse effect of Zn–DTPA encapsulated lecithin liposomes in rats.

On the extraction of MoO x photothermally active nanoparticles by gel filtration from a byproduct of few-layer MoS2 exfoliation

Gel filtration is a versatile technique employed for biological molecules and nanoparticles, offering their reproducible classification based on size and shape. Colloidal nanoparticles are of significant interest in biomedical applications due to a large number of solution-based bioconjugation procedures. Nevertheless, the inherent polydispersity of the nanoparticles produced by various techniques necessitates the employment of high yield separation and purification techniques. Here we demonstrate the employment of gel filtration on non-stoichiometric plasmonic MoO x nanoparticles, prepared by an oxidation process during liquid-phase exfoliation of few-layer MoS2 nanosheets. This resulted in the separation of two types of MoO x particles, in the form of two different chromatographic fractions. They showed different sizes, morphological and optical properties. The fraction containing smaller particles with diameters of 1-4 nm, exhibited an increased absorbance peak in the near IR region and responded with a significant temperature increase to laser irradiation at the wavelength close to the maximal absorption. The fraction with the larger particles from 3 up to 10 nm, showed weak photoluminescence and a preferred orientation upon the deposition on a planar substrate. However, it had no absorbance in the near IR compared to the former fraction. According to our knowledge, this is the first time that the gel filtration was applied to the separation of molybdenum oxide nanomaterials. This step ensured the isolation of plasmonic MoO x nanoparticles suitable for further bioconjugation and target photothermal treatment.

Nanomaterials for Skin Delivery of Cosmeceuticals and Pharmaceuticals

Skin aging is described as dermatologic changes either naturally occurring over the course of years or as the result of the exposure to environmental factors (e.g., chemical products, pollution, infrared and ultraviolet radiations). The production of collagen and elastin, the main structural proteins responsible for skin strength and elasticity, is reduced during aging, while their role in skin rejuvenation can trigger a wrinkle reversing effect. Elasticity loss, wrinkles, dry skin, and thinning are some of the signs that can be associated with skin aging. To overcome skin aging, many strategies using natural and synthetic ingredients are being developed aiming to reduce the signs of aging and/or to treat age-related skin problems (e.g., spots, hyper- or hypopigmentation). Among the different approaches in tissue regeneration, the use of nanomaterials loaded with cosmeceuticals (e.g., phytochemicals, vitamins, hyaluronic acid, and growth factors) has become an interesting alternative. Based on their bioactivities and using different nanoformulations as efficient delivery systems, several cosmeceutical and pharmaceutical products are now available on the market aiming to mitigate the signs of aged skin. This manuscript discusses the state of the art of nanomaterials commonly used for topical administration of active ingredients formulated in nanopharmaceuticals and nanocosmeceuticals for skin anti-aging.

A method for the separation of TiO2 nanoparticles from Water through encapsulation with lecithin liposomes followed by adsorption onto poly(L-lysine) coated glass surfaces

Increasing use of nanomaterials in the consumer and pharmaceutical industries has led to emerging contamination by released nanoparticles in wastewater and drinking water, causing major concerns for public health. Titanium dioxide (TiO₂) nanoparticles are one of the major nanoparticles of growing concern with a strong need for efficient removal. In this work, removal of TiO₂ nanoparticles from water was investigated by first coating with polydopamine (PDA) and then encapsulating within lecithin liposomes for adsorption onto poly-l-lysine (PLL) coated glass surfaces. The PLL coating was confirmed using atomic force microscopy, with a thickness of 30 nm. An average percent removal of 58% with a standard deviation of 18% was obtained for concentrations ranging from 5 mg/L to 125 mg/L following capture experiments. This method provides a promising solution to alleviate the potential health hazard caused by TiO₂ nanoparticles. It is minimally affected by such water quality variables as alkalinity, ionic strength and humic acid. No coagulation, flocculation and sedimentation stages are necessary.