A general strategy for self-assembly of nanosized building blocks on liquid/liquid interfaces.

A family of water/oil interfaces is introduced to provide effective platforms for rapid fabrication of large-area self-assembled nanofilms composed of various nanosized building blocks, including nanoparticles (NPs), nanocubes (NC), nanowires (NWs), and nanosheets, at room temperature. As a general interfacial assembly method, NWs and NPs are co-assembled at the liquid/liquid interface. The as-prepared co-assembled Ag NW and Ag NC films show high surface-enhanced Raman spectroscopy (SERS) intensity, the SERS performance being strongly dependent on the number ratio of the two kinds of nanosized building blocks. The results demonstrate that this interfacial system provides a general method for the assembly of various nanosized building blocks with different shapes and dimensionalities, and thus paves an alternative pathway for further applications of macroscopic assemblies with different functionalities.

Development of local injectable, bone-targeting nanocarriers of triptolide for treatment of bone-only metastasis.

Triptolide (TP) is known for its diverse pharmacological activities but also its delivery and toxicity issues. This study aimed at exploiting TP's anticancer effects at lower risk of systemic toxicity by developing local-injectable "bone-targeting TP nanoparticle" (TPN) for bone-only metastasis treatment. The lipid/oil-based TPNs decorated with alendronate (ALE) achieved size of 70.4-111.2 nm with good dispersion stability. The drug encapsulation efficiency reached 97 % and drug release profiles were in biphasic, controlled manner lasting for 5 days in medium with serum proteins and calcium. TPNs were more cytotoxic than free TP against MDA-MB-231 breast cancer cells (IC50: 16.40 ± 0.80 nM vs 25.45 ± 1.83 nM, P < 0.05) but less cytotoxic against MC3T3-E1 osteoblasts (P < 0.05). When combined with paclitaxel or docetaxel, low dose TPN (containing 10 nM) significantly increased the effectiveness of the two chemotherapy drugs against MDA-MB-231 (IC50 values decreased from 7.3 nM to 2.5 nM for docetaxel; from 4.6 nM to 1.1 nM), indicating potent chemosensitization effects. Retardation of in vitro cancer cell migration by TPN was also observed in the standard scratch assay. ALE decoration significantly enhanced the TPN affinity for both calcium hydroxyapatite and porcine bone chip models, which led to enhancement in TP retention in the bones up to 8.1-fold versus free drug. Overall, TPN demonstrated good potential as a local-injectable, bone-targeted nanotherapy tailored for eradication of bone-only metastasis at reduced risk of systemic toxicity.

Fast Independent Component Analysis Algorithm-Based Diagnosis of L5 Nerve Root Compression and Changes of Brain Functional Areas Using 3D Functional Magnetic Resonance Imaging.

In this paper, the application of 3-dimensional (3D) functional magnetic resonance imaging (FMRI) in the diagnosis of the 5th lumbar (L5) nerve root compression and brain functional areas in patients with lumbar disc herniation (LDH) was analyzed. The traditional fast independent component analysis (Fast ICA) algorithm was optimized based on the modified whitening matrix to establish a new type of Modified-Fast ICA (M-Fast ICA) algorithm that was compared with the introduced traditional Fast ICA and ICA. M-Fast ICA was applied to the 3D FMRI diffusion tensor imaging (DTI) evaluation of 65 patients with L5 nerve root pain due to LDH (group A) and 50 healthy volunteers (group B). The values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) in the lumbar nerve roots (L3, L4, L5, and the 1st sacral vertebra (S1)) were recorded among subjects from the two groups. Besides, the score of edema degree in the lumbar nerve roots (L5 and S1) and activity of brain functional areas were also recorded among all subjects of the two groups. The results showed that the mean square error of M-Fast ICA was smaller than that of traditional Fast ICA and ICA, while its signal-to-noise ratio (SNR) was greater than that of Fast ICA and ICA (P < 0.05). The FA of L5 and S1 nerve roots in patients of group A was sharply lower than the values of group B, while the ADC of patients in group A was greater than that of the control group (P < 0.05). Besides, the score of edema in L5 and S1 nerve roots of patients in group A increased in contrast to group B (P < 0.05). The brain areas were activated after surgery including bilateral temporal lobe, left thalamus, splenium of corpus callosum, and right internal capsule. In conclusion, the 3D image denoising performance of M-Fast ICA optimized and constructed in this study was superior to that of the traditional Fast ICA and ICA. The FA of patients with L5 nerve root pain due to LDH decreased steeply, while the ADC increased dramatically. L5 nerve root pain caused by LDH resulted in changes in brain functional areas of the patients to inhibit the resting state default network activity, and the corresponding brain functional areas could be activated through treatment.

Lipid-Based Nanocarriers for RNA Delivery.

RNA-interference (RNAi) agents such as small-interfering RNA (siRNA) and micro-RNA (miRNA) have strong potential as therapeutic agents for the treatment of a broad range of diseases such as malignancies, infections, autoimmune diseases and neurological diseases that are associated with undesirable gene expression. In recent years, several clinical trials of RNAi therapeutics especially siRNAs have been conducted with limited success so far. For systemic administration of these poorly permeable and easily degradable macromolecules, it is obvious that a safe and efficient delivery platform is highly desirable. Because of high biocompatibility, biodegradability and solid track record for clinical use, nanocarriers made of lipids and/or phospholipids have been commonly employed to facilitate RNA delivery. In this article, the key features of the major sub-classes of lipid-based nanocarriers, e.g. liposomes, lipid nanoparticles and lipid nanoemulsions, will be reviewed. Focus of the discussion is on the various challenges researchers face when developing lipid-based RNA nanocarriers, such as the toxicity of cationic lipids and issues related to PEGylated lipids, as well as the strategies employed in tackling these challenges. It is hoped that by understanding more about the pros and cons of these most frequently used RNA delivery systems, the pharmaceutical scientists, biomedical researchers and clinicians will be more successful in overcoming some of the obstacles that currently limit the clinical translation of RNAi therapy.

Ordering Ag nanowire arrays by a glass capillary: a portable, reusable and durable SERS substrate.

Assembly of nanowires into ordered macroscopic structures with new functionalities has been a recent focus. In this Letter, we report a new route for ordering hydrophilic Ag nanowires with high aspect ratio by flowing through a glass capillary. The present glass capillary with well-defined silver nanowire films inside can serve as a portable and reusable substrate for surface-enhanced Raman spectroscopy (SERS), which may provide a versatile and promising platform for detecting mixture pollutions. By controlling the flow parameters of nanowire suspensions, initially random Ag nanowires can be aligned to form nanowire arrays with tunable density, forming cambered nanowire films adhered onto the inner wall of the capillary. Compared with the planar ordered Ag nanowire films by the Langmuir-Blodgett (LB) technique, the cambered nanowire films show better SERS performance.