No abstract

Glioma is a fatal disease with limited treatment options and very short survival. Although chemotherapy is one of the most important strategies in glioma treatment, it remains extremely clinically challenging largely due to the blood−brain barrier (BBB) and the blood−brain tumor barrier (BBTB). Thus, the development of nanoparticles with both BBB and BBTB penetrability, as well as gliomatargeting feature, is extremely important for the therapy of glioma. New findings in nanomedicine are promoting the development of novel biomaterials. Herein, we designed a red blood cell membrane-coated solid lipid nanoparticle (RBCSLN)-based nanocarrier dual-modified with T7 and NGR peptide (T7/NGR-RBCSLNs) to accomplish these objectives. As a new kind of biomimetic nanovessels, RBCSLNs preserve the complex biological functions of natural cell membranes while possessing physicochemical properties that are needed for efficient drug delivery. T7 is a ligand of transferrin receptors with seven peptides that is able to circumvent the BBB and target to glioma. NGR is a peptide ligand of CD13 that is overexpressed during angiogenesis, representing an excellent glioma-homing property. After encapsulating vinca alkaloid vincristine as the model drug, T7/NGR-RBCSLNs exhibited the most favorable antiglioma effects in vitro and in vivo by combining the dual-targeting delivery effect. The results demonstrate that dual-modified biomimetic nanoparticles provide a potential method to improve drug delivery to the brain, hence increasing glioma therapy efficacy.

Manufacturers of food fresh containers use nanosilver as an antimicrobial agent, but the safe impacts of nanosilver release from commercial products are unknown. The nanoparticles that migrate from the consumer products should be determined to assess the safety and/or risks of nanotechnology. This paper describes experimental work carried out on one kind of commercial food fresh container (polyethylene plastic bags). In the experiments, the range of temperatures was from room temperature (about 25°C) to 50°C, the range of time intervals was from 3 to 15 days, and the bags were filled with four kinds of food-simulating solutions representing water, acid, alcohol and fatty foods, respectively. Microwave digestion method was used for sample pre-treatment. The scanning electron microscopy and energy-dispersive X-ray (SEM/EDX) analysis was used to confirm the presence and morphology of nanosilver additives, and the atomic absorption spectroscopy (AAS) analysis was applied, showing that the commercial bags contained 100 μg (Ag)/g (plastic materials). Strong evidences from SEM/EDX and AAS analyses were found, indicating the migration of nanosilver from the polyethylene bags into food-simulating solutions. The amount of nanosilver migration was observed as increasing with storage time and temperature.

Neuronal mitochondrial dysfunction caused by excessive reactive oxygen species (ROS) is an early event of sporadic Alzheimer's disease (AD), and considered to be a key pathologic factor in the progression of AD. The targeted delivery of the antioxidants to mitochondria of injured neurons in brain is a promising therapeutic strategy for AD. A safe and effective drug delivery system (DDS) which is able to cross the blood-brain barrier (BBB) and target neuronal mitochondria is necessary. Recently, bioactive materials-based DDS has been widely investigated for the treatment of AD. Herein, we developed macrophage (MA) membrane-coated solid lipid nanoparticles (SLNs) by attaching rabies virus glycoprotein (RVG29) and triphenylphosphine cation (TPP) molecules to the surface of MA membrane (RVG/TPP-MASLNs) for functional antioxidant delivery to neuronal mitochondria. According to the results, MA membranes camouflaged the SLNs from being eliminated by RES-rich organs by inheriting the immunological characteristics of macrophages. The unique properties of the DDS after decoration with RVG29 on the surface was demonstrated by the ability to cross the BBB and the selective targeting to neurons. After entering the neurons in CNS, TPP further lead the DDS to mitochondria driven by electric charge. The Genistein (GS)- encapsulated DDS (RVG/TPP-MASLNs-GS) exhibited the most favorable effects on reliveing AD symptoms in vitro and in vivo by the synergies gained from the combination of MA membranes, RVG29 and TPP. These results demonstrated a promising therapeutic candidate for delaying the progression of AD via neuronal mitochondria-targeted delivery by the designed biomimetic nanosystems.

We have developed a method of controllable synthesis of MgO with various morphologies by adjusting the composition and phase structure of magnesium carbonate hydrate (MCH). The phase structure of the MCH varied from monoclinic Mg 5 (CO 3 ) 4 (OH) 2 (H 2 O) 4 to hexagonal MgCO 3 by changing the concentration of Mg 2+ and HCO 3 -; the corresponding morphology of the MCH ranges from nanoflakes and flowerlike microspheres composed of nanoflakes to layer-like rhombohedra and microspheres composed of rhombohedra. After annealing, four kinds of mesoporous cubic MgO micronano structures were obtained with their original morphologies. Because of the high specific surface area, MgO mesoporous nanoflakes and flowerlike microsphers exhibited excellent absorption performance for common toxic heavy metal ions and organic pollutants and are expected to be a potential absorbent in wastewater treatment.