10 research outputs found
The Joint Effect of Individual GMA and Team GMA on Safety Participation.
<p>The Joint Effect of Individual GMA and Team GMA on Safety Participation.</p
Means, standard deviation, and correlations of all variables (Nâ=â312).
<p>Note: *p<.01, **p<.001.</p
Aerobic Transition-Metal-Free Visible-Light Photoredox Indole Câ3 Formylation Reaction
An aerobic visible-light-promoted
indole C-3 formylation reaction
catalyzed by Rose Bengal has been developed. This transition-metal-free
process employs molecular oxygen as the terminal oxidant and uses
TMEDA as the one-carbon source through CâN bond cleavage. The
reaction is compatible with a variety of functional groups
Means, standard deviation, and Zero-order correlations of all variables (nâ=â99).
<p><i>Note:</i><sup>*</sup>p<.05, <sup>**</sup>p<.01.</p
Hierarchical multiple regression predicting self-reported safety compliance (nâ=â99).
<p><i>Note</i>: <sup>*</sup>p<.05, <sup>**</sup>p<.01.</p
Moderating effects of inhibition on the influences of controlled and automatic cognitions on safety behaviors.
<p>Panel A shows the moderating effect of inhibition on the influence of safety compromise on safety compliance. Panel B shows the moderating effect of inhibition on the influence of automatic association on safety compliance. Panel C shows the moderating effect of inhibition on the influence of self-reported safety attitude on safety participation. Panel D shows the moderating effect of inhibition on the influence of automatic association on safety participation.</p
Hierarchical multiple regression predicting self-reported safety participation (nâ=â99).
<p><i>Note</i>: <sup>*</sup>p<.05, <sup>**</sup>p<.01.</p
Engineering the Aromaticity of Cationic Helical Polypeptides toward âSelf-Activatedâ DNA/siRNA Delivery
The development of
potent yet nontoxic membrane-penetrating materials is in high demand
for effective intracellular gene delivery. We have recently developed
α-helical polypeptides which afford potent membrane activities
to facilitate intracellular DNA delivery via both endocytosis and
the nonendocytic âpore formationâ mechanism. Endocytosis
will cause endosomal entrapment of the DNA cargo, while excessive
âpore formationâ would cause appreciable cytotoxicity.
Additionally, helical polypeptides with stiff, rodlike structure suffer
from low siRNA binding affinity. To address such critical issues,
we herein incorporated various aromatic domains (benzyl, naphthyl,
biphenyl, anthryl, and pyrenyl) into the side-chain terminals of guanidine-rich,
helical polypeptides, wherein the flat-rigid shape, Ï-electronic
structures of aromatic motifs âself-activatedâ the membrane-penetrating
capabilities of polypeptides to promote intracellular gene delivery.
Benzyl (Bn)- and naphthyl (Naph)-modified polypeptides demonstrated
the highest DNA uptake level that outperformed the unmodified polypeptide,
P2, by âŒ4 fold. More importantly, compared with P2, Bn- and
Naph-modified polypeptides allowed more DNA cargos to be internalized
via the nonendocytic pathway, which significantly bypassed the endosomal
entrapment and accordingly enhanced the transfection efficiency by
up to 42 fold, outperforming PEI 25k as the commercial reagent by
3â4 orders of magnitude. The aromatic modification also improved
the siRNA condensation capability of polypeptides, achieving notably
enhanced gene-silencing efficiency against tumor necrosis factor-α
to treat acute hepatic inflammation. Furthermore, we revealed that
aromaticity-augmented membrane activity was accompanied by comparable
or even significantly reduced âpore formationâ capability,
thus leading to diminished cytotoxicity at high concentrations. This
study therefore provides a promising approach to manipulate the membrane
activities and penetration mechanisms of polycations, which overcomes
the multiple critical barriers preventing effective and safe gene
delivery
High Drug Loading and Sub-Quantitative Loading Efficiency of Polymeric Micelles Driven by DonorâReceptor Coordination Interactions
Polymeric micelles
are extensively used for the delivery of hydrophobic
drugs, which, however, suffer from unsatisfactory drug loading, colloidal
uniformity, formulation stability, and drug release. Herein, we demonstrate
a convenient strategy to prepare micelles with ultrahigh drug loading
via the incorporation of polymerâdrug coordination interactions.
An amphiphilic copolymer containing pendant phenylboronic acid as
electron acceptor unit was synthesized, which afforded donorâacceptor
coordination with doxorubicin to obtain micelles with ultrahigh drug
loading (âŒ50%), nearly quantitative loading efficiency (>95%),
uniform size, and colloidal stability. Besides, the encapsulated drug
can be effectively and selectively released in response to the high
reactive oxygen species levels in cancer cells, which potentiated
the anticancer efficacy and reduced systemic toxicity. Apart from
doxorubicin, the current platform could be extended to other drugs
with electron-donating groups (e.g., epirubicin and irinotecan), rendering
a simple and robust strategy for enabling high drug loading in polymeric
micelles and cancer-specific drug release
Efficient Gene Delivery Mediated by a Helical Polypeptide: Controlling the Membrane Activity via Multivalency and Light-Assisted Photochemical Internalization (PCI)
The
development of robust and nontoxic membrane-penetrating materials
is highly demanded for nonviral gene delivery. Herein, a photosensitizer
(PS)-embedded, star-shaped helical polypeptide was developed, which
combines the advantages of multivalency-enhanced intracellular DNA
uptake and light-strengthened endosomal escape to enable highly efficient
gene delivery with low toxicity. 5,10,15,20-Tetrakis-(4-aminophenyl)
porphyrin as a selected PS initiated ring-opening polymerization of <i>N</i>-carboxyanhydride and yielded a star-shaped helical polypeptide
after side-chain functionalization with guanidine groups. The star
polypeptide afforded a notably higher transfection efficiency and
lower cytotoxicity than those of its linear analogue. Light irradiation
caused almost complete (âŒ90%) endosomal release of the DNA
cargo via the photochemical internalization (PCI) mechanism and further
led to a 6â8-fold increment of the transfection efficiency
in HeLa, B16F10, and RAW 264.7 cells, outperforming commercial reagent
25k PEI by up to 3 orders of magnitude. Because the PS and DNA cargoes
were compartmentalized distantly in the core and polypeptide layers,
respectively, the generated reactive oxygen species caused minimal
damage to DNA molecules to preserve their transfection potency. Such
multivalency- and PCI-potentiated gene delivery efficiency was also
demonstrated in vivo in melanoma-bearing mice. This study thus provides
a promising strategy to overcome the multiple membrane barriers against
nonviral gene delivery