Surface Functionalization of Hydrophobic Nanocrystals with One Particle per Micelle for Bioapplications

A facile and general strategy was successfully developed for the surface modification of kinds of hydrophobic inorganic nanomaterials with various chemical compositions, shapes, and sizes. Via this ultrasonication assistant encapsulation technology, these hydrophobic inorganic nanocrystals were successfully encapsulated into the carboxylated phospholipids and polymers micelles with one particle per micelle. The surface modified nanocrystals were characterized by transmission electron microscopy (TEM), Fourier-transform infrared (FTIR), and thermogravimetric analysis (TGA). After encapsulation, the particle size, shape, and optical and magnetic properties were effectively retained. These functionalized nanocrystals are highly water-stable and biocompatible. After being bioconjugated with the antibodies, the functionalized quantum dots (QDs) have been successfully used as biolabels for targeted cell fluorescence imaging

Supplementary Data from Role of ATP-Binding Cassette and Solute Carrier Transporters in Erlotinib CNS Penetration and Intracellular Accumulation

Supplementary Figures S1-S3; Supplementary Tables S1-S3.</p

Template-Free Synthesis and Characterization of Single-Phase Voided Poly(<i>o</i>-anisidine) and Polyaniline Colloidal Spheres

Single-phase hollow poly(o-anisidine) colloidal spheres with uniform sizes were directly synthesized in dilute aqueous solution of o-anisidine in the presence of a small amount of an initiator, cupric acetate or basic cupric bromide, Cu2(OH)3Br, under hydrothermal conditions. The void volume and size of hollow poly(o-anisidine) colloidal spheres can be readily tuned by varying the hydrothermal reaction time and adjusting the ratios between the starting reactants. The formation of voided poly(o-anisidine) results from a diffusion-related process driven by the relatively large concentration change between polymer core and solution as well as the high pressure and temperature under hydrothermal conditions. At the same time, the mesostructures of poly(o-anisidine) are dependent on reaction time, temperature, and monomer concentration. An extension of this one-pot synthetic method yields hollow polyaniline colloidal spheres

Monodisperse Fluorescent Organic/Inorganic Composite Nanoparticles: Tuning Full Color Spectrum

Monodisperse fluorescent organic/inorganic composite nanoparticles are synthesized through the spontaneous self-assembly of block copolymer polystyrene-<i>block</i>-poly­(vinylpyridine) and rare-earth ions (europium, terbium, thulium, etc.). Depending on the rare-earth ions selected, tunable light-emission colors, including the primary red, green, and blue, are accomplished. Further, by stoichiometric mixing of the nanoparticles that emit different colors, the full color spectrum can be accessed. Both electron microscopy and spectroscopic characterizations confirm specific interactions of rare-earth and block copolymers. The resulting nanoparticles are monodisperse as characterized by dynamic light scattering. They are very stable and can be dispersed in common solvents, and together with homopolymers, they form ordered arrays and thin films (both supported and free-standing) upon solvent evaporation. The resulting nanoparticle thin films exhibit mechanical flexibility for ease of processing or device integration

Microemulsion-Assisted Self-Assembly and Synthesis of Size-Controlled Porphyrin Nanocrystals with Enhanced Photocatalytic Hydrogen Evolution

Design and engineering of highly efficient light-harvesting nanomaterial systems to emulate natural photosynthesis for maximizing energy conversion have stimulated extensive efforts. Here we present a new class of photoactive semiconductor nanocrystals that exhibit high-efficiency energy transfer for enhanced photocatalytic hydrogen production under visible light. These nanocrystals are formed through noncovalent self-assembly of In­(III) meso-tetraphenylporphine chloride (InTPP) during microemulsion assisted nucleation and growth process. Through kinetic control, a series of uniform nanorods with controlled aspect ratio and high crystallinity have been fabricated. Self-assembly of InTPP porphyrins results in extensive optical coupling and broader coverage of the visible spectrum for efficient light harvesting. As a result, these nanocrystals display excellent photocatalytic hydrogen production and photostability under the visible light in comparison with the commercial InTPP porphyrin powders

Abnormal Functional Connectivity of Amygdala in Late-Onset Depression Was Associated with Cognitive Deficits

<div><p>Background</p><p>Major depressive disorder (MDD) is associated with decreased function of cortico-limbic circuits, which play important roles in the pathogenesis of MDD. Abnormal functional connectivity (FC) with the amygdala, which is involved in cortico-limbic circuits, has also been observed in MDD. However, little is known about connectivity alterations in late-onset depression (LOD) or whether disrupted connectivity is correlated with cognitive impairment in LOD.</p><p>Methods and Results</p><p>A total of twenty-two LOD patients and twenty-two matched healthy controls (HC) underwent neuropsychological tests and resting state functional magnetic resonance imaging (rs-fMRI). Regional homogeneity (ReHo) and FC with bilateral amygdala seeds were used to analyze blood oxygen level-dependent fMRI data between two groups. Compared with HC, LOD patients showed decreased ReHo in the right middle frontal gyrus and left superior frontal gyrus. In the LOD group, the left amygdala had decreased FC with the right middle frontal gyrus and the left superior frontal gyrus in the amygdala positive network, and it had increased FC with the right post-central gyrus in the amygdala negative network. However, significantly reduced FC with the right amygdala was observed in the right middle occipital gyrus in the amygdala negative network. Further correlative analyses revealed that decreased FC between the amygdala and the right middle occipital gyrus was negatively correlated with the verbal fluency test (VFT, <i>r</i> = −0.485, <i>P</i> = 0.022) and the digit span test (DST, <i>r</i> = −0.561, <i>P</i> = 0.007).</p><p>Conclusions</p><p>Our findings of reduced activity of the prefrontal gyrus and abnormal FC with the bilateral amygdala may be key markers of cognitive dysfunction in LOD patients.</p></div

Significant Correlations between Neuropsychological Measurements and ReHo/FC with Amygdala in HC group.

<p>Note: this table only showed the significant correlations by Spearman's correlation. *: <i>P<</i>0.05.</p

Abnormal resting-state functional connectivity of posterior cingulate cortex in amnestic type mild cognitive impairment

Amnestic type mild cognitive impairment (aMCI) refers to a transitional stage between normal aging and Alzheimer's disease (AD). Whilst posterior cingulate cortex (PCC) is believed to have a key role in a default network and be involved in the pathophysiology of AD, few studies have investigated whole-brain functional connectivity of PCC during resting state, or investigated the relationship between abnormal functional connectivity and disturbance in cognitive function in aMCI patients. Resting-state functional connectivity analysis was used to examine the temporal correlation between PCC and whole-brain regions in 30 aMCI patients and 26 well-matched controls. Further analysis involved evaluation of possible relationships between functional connectivity measures and cognitive function. Regions of decreased functional connectivity were identified in aMCI patients, most notably in temporal cortex, whilst significantly increased functional connectivity was mainly in frontal cortex. In addition, functional connectivity of PCC and temporal cortex was associated with the performance of neuropsychological tests in aMCI patients. This would be consonant with the recruitment of compensatory mechanisms and the process of offset functional impairments appearing as neuropathologic develops, and resting-state connectivity disturbance of PCC–temporal cortex may be a central role in cognitive deficit in aMCI patients

Adsorption of DNA Oligonucleotides by Self-Assembled Metalloporphyrin Nanomaterials

Porphyrin assemblies have controllable morphology, high biocompatibility, and good optical properties and were widely used in biomedical diagnosis and treatment. With the development of DNA biotechnology, combining DNA with porphyrin assemblies can broaden the biological applications of porphyrins. Porphyrin assemblies can serve as nanocarriers for DNA, although the fundamental interactions between them are not well understood. In this work, zinc meso-tetra­(4-pyridyl)­porphyrin (ZnTPyP) assemblies were prepared in the presence of various surfactants and at different pH values, yielding a variety of aggregation forms. Among them, the hexagonal stacking form exposes more pyridine substituents, and the hydrogen bonding force between the substituents and the DNA bases allows the DNA to be quickly adsorbed on the surface of the assemblies. The effects of DNA sequence and length were systematically tested. In particular, the adsorption of duplex DNA was less efficient compared to the adsorption of single-stranded DNA. This fundamental study is useful for the further combination of DNA and porphyrin assemblies to prepare new functional hybrid nanomaterials

Demographic and neuropsychological data between LOD group and HC group.

<p>LOD: late-onset depression; HC: healthy controls; MMSE: Mini mental state exam; HAMA: Hamilton Anxiety Scale; HAMD: Hamilton Depression Scale; AVLT-delayed recall: Auditory Verbal Learning Test-delayed recall; SDMT: Symbol digit modalities test; DST: Digit span test-forward and backward; VFT: Verbal fluency test-animal and verb; TMT-A: Trail making test-A; TMT- B: Trail making test- B.</p>a<p>Independent-samples t-test.</p>b<p>Chi square test.</p>c<p>Analysis of covariance.</p