6 research outputs found
Green Chemistry Approach to Surface Decoration: Trimesic Acid Self-Assembly on HOPG
We have investigated trimesic acid (1,3,5-benzenetricarboxylic
acid, TMA) adsorption on highly oriented pyrolytic graphite (HOPG)
surface from aqueous medium at room temperature. Both atomic force
microscopy and scanning tunneling microscopy were utilized to follow
the adsorption dynamics and molecular arrangements. We have proposed
an optimized green chemistry approach for fabricating trimesic acid
monolayer structures on HOPG. A chicken-wire arrangement for adsorbed
molecules with an average pore size of 11 ± 1 Å was established
and was observed using both scanning techniques. This structure was
found to be stable in the ambient for at least two days
Ferritin-Based New Magnetic Force Microscopic Probe Detecting 10 nm Sized Magnetic Nanoparticles
A single-molecule ferritin picking-up process was realized with the use of AFM, which was enhanced by employing controlled dendron surface chemistry. The approach enabled the placement of a single ferritin protein molecule at the very end of an AFM tip. When used for magnetic force microscopy (MFM) imaging, the tips were able to detect magnetic interactions of approximately 10 nm sized magnetic nanoparticles. The single ferritin tip also showed the characteristics of a “multifunctional” MFM probe that can sense the magnetic force from magnetic materials as well as detect the biomolecular interaction force with DNAs on the surface. The multifunctional tip enabled us not only to investigate the specific molecular interaction but also to image the magnetic interaction between the probe and the substrate, in addition to allowing the common capability of topographic imaging. Because the protein engineering of ferritin and the supporting coordination and conjugation chemistry are well-established, we envisage that it would be straightforward to extend this approach to the development of various single magnetic particle MFM probes of different compositions and sizes
Prenatal central nervous system anomaly with skeletal dysplasia associated with a <i>de novo</i> interstitial tandem triplication of chromosome 14
Prenatal central nervous system anomaly with skeletal dysplasia associated with a <i>de novo</i> interstitial tandem triplication of chromosome 1
Understanding the Interfacial Properties of Nanostructured Liquid Crystalline Materials for Surface-Specific Delivery Applications
Nonlamellar liquid crystalline dispersions such as cubosomes
and
hexosomes have great potential as novel surface-targeted active delivery
systems. In this study, the influence of internal nanostructure, chemical
composition, and the presence of Pluronic F127 as a stabilizer, on
the surface and interfacial properties of different liquid crystalline
particles and surfaces, was investigated. The interfacial properties
of the bulk liquid crystalline systems with coexisting excess water
were dependent on the internal liquid crystalline nanostructure. In
particular, the surfaces of the inverse cubic systems were more hydrophilic
than that of the inverse hexagonal phase. The interaction between
F127 and the bulk liquid crystalline systems depended on the internal
liquid crystalline structure and chemical composition. For example,
F127 adsorbed to the surface of the bulk phytantriol cubic phase,
while for monoolein cubic phase, F127 was integrated into the liquid
crystalline structure. Last, the interfacial adsorption behavior of
the dispersed liquid crystalline particles also depended on both the
internal nanostructure and the chemical composition, despite the dispersions
all being stabilized using F127. The findings highlight the need to
understand the specific surface characteristics and the nature of
the interaction with colloidal stabilizer for understanding and optimizing
the behavior of nonlamellar liquid crystalline systems in surface
delivery applications
Multicomponent Synthetic Polymers with Viral-Mimetic Chemistry for Nucleic Acid Delivery
The ability to deliver genetic material for therapy remains
an
unsolved challenge in medicine. Natural gene carriers, such as viruses,
have evolved sophisticated mechanisms and modular biopolymer architectures
to overcome these hurdles. Here we describe synthetic multicomponent
materials for gene delivery, designed with features that mimic virus
modular components and which transfect specific cell lines with high
efficacy. The hierarchical nature of the synthetic carriers allows
the incorporation of membrane-disrupting peptides, nucleic acid binding
components, a protective coat layer, and an outer targeting ligand
all in a single nanoparticle, but with functionality such that each
is utilized in a specific sequence during the gene delivery process.
The experimentally facile assembly suggests these materials could
form a generic class of carrier systems that could be customized for
many different therapeutic settings
Design, Synthesis, and Biological Evaluation of Novel Chromanone Derivatives as Multifunctional Agents for the Treatment of Alzheimer’s Disease
Based
on a multitarget strategy, a series of novel chromanone–1-benzyl-1,2,3,6-tetrahydropyridin
hybrids were identified for the potential treatment of Alzheimer’s
disease (AD). Biological evaluation demonstrated that these hybrids
exhibited significant inhibitory activities toward acetylcholinesterase
(AChE) and monoamine oxidase B (MAO-B). The optimal compound C10 possessed excellent dual AChE/MAO-B inhibition both in
terms of potency and equilibrium (AChE: IC50 = 0.58 ±
0.05 μM; MAO-B: IC50 = 0.41 ± 0.04 μM).
Further molecular modeling and kinetic investigations revealed that
compound C10 was a dual-binding inhibitor bound to both
the catalytic anionic site and peripheral anionic site of AChE. In
addition, compound C10 exhibited low neurotoxicity and
potently inhibited AChE enzymatic activity. Furthermore, compound C10 more effectively protected against mitochondrial dysfunction
and oxidation than donepezil, strongly inhibited AChE-induced amyloid
aggregation, and moderately reduced glutaraldehyde-induced phosphorylation
of tau protein in SH-SY5Y cells. Moreover, compound C10 displayed largely enhanced improvements in cognitive behaviors and
spatial memory in a scopolamine-induced AD mice model with better
efficacy than donepezil. Overall, the multifunctional profiles of
compound C10 suggest that it deserves further investigation
as a promising lead for the prospective treatment of AD