17 research outputs found
Multi-template synthesis of hierarchically porous carbon spheres with potential application in supercapacitors
A new and simple multi-template approach towards hierarchical porous carbon (HPC) materials was reported. HPC spheres were prepared by using hierarchical silica capsules (HSCs) as the hard template and triblock copolymer Pluronic P123 as the soft template. Three types of pores were tunably constructed in the HPC spheres in a wide size range of 3.0 to 100 nm. Since the HSCs were in situ constructed by silica nanoparticles, which were formed from the sol–gel system of tetraethylorthosilicate and (3-aminopropyl)triethoxysilane (APTES), the porous structures of HPCs were simply controlled by changing the size of silica nanoparticles, i.e. by varying the APTES content. Thanks to their high surface areas and interconnected pores, the HPCs exhibited good electrochemical performance with specific capacitances of up to 170 F g−1 and outstanding cycling stability without capacitance loss after 5000 cycles
Iron Chelation Nanoparticles with Delayed Saturation as an Effective Therapy for Parkinson Disease
Iron accumulation
in substantia nigra pars compacta (SNpc) has
been proved to be a prominent pathophysiological feature of Parkinson’s
diseases (PD), which can induce the death of dopaminergic (DA) neurons,
up-regulation of reactive oxygen species (ROS), and further loss of
motor control. In recent years, iron chelation therapy has been demonstrated
to be an effective treatment for PD, which has shown significant improvements
in clinical trials. However, the current iron chelators are suboptimal
due to their short circulation time, side effects, and lack of proper
protection from chelation with ions in blood circulation. In this
work, we designed and constructed iron chelation therapeutic nanoparticles
protected by a zwitterionic polyÂ(2-methacryloyloxyethyl phosphorylcholine)
(PMPC) to delay the saturation of iron chelators in blood circulation
and prolong the <i>in vivo</i> lifetime, with HIV-1 trans-activating
transcriptor (TAT) served as a shuttle to enhance the blood-brain
barrier (BBB) permeability. We explored and investigated whether the
Parkinsonian neurodegeneration and the corresponding symptoms in behaviors
and physiologies could be prevented or reversed both <i>in vitro</i> and <i>in vivo</i>. The results demonstrated that iron
chelator loaded therapeutic nanoparticles could reverse functional
deficits in Parkinsonian mice not only physiologically but also behaviorally.
On the contrary, both untreated PD mice and non-TAT anchored nanoparticle
treated PD mice showed similar loss in DA neurons and difficulties
in behaviors. Therefore, with protection of zwitterionic polymer and
prolonged <i>in vivo</i> lifetime, iron chelator loaded
nanoparticles with delayed saturation provide a PD phenotype reversion
therapy and significantly improve the living quality of the Parkinsonian
mice
Iron Chelation Nanoparticles with Delayed Saturation as an Effective Therapy for Parkinson Disease
Iron accumulation
in substantia nigra pars compacta (SNpc) has
been proved to be a prominent pathophysiological feature of Parkinson’s
diseases (PD), which can induce the death of dopaminergic (DA) neurons,
up-regulation of reactive oxygen species (ROS), and further loss of
motor control. In recent years, iron chelation therapy has been demonstrated
to be an effective treatment for PD, which has shown significant improvements
in clinical trials. However, the current iron chelators are suboptimal
due to their short circulation time, side effects, and lack of proper
protection from chelation with ions in blood circulation. In this
work, we designed and constructed iron chelation therapeutic nanoparticles
protected by a zwitterionic polyÂ(2-methacryloyloxyethyl phosphorylcholine)
(PMPC) to delay the saturation of iron chelators in blood circulation
and prolong the <i>in vivo</i> lifetime, with HIV-1 trans-activating
transcriptor (TAT) served as a shuttle to enhance the blood-brain
barrier (BBB) permeability. We explored and investigated whether the
Parkinsonian neurodegeneration and the corresponding symptoms in behaviors
and physiologies could be prevented or reversed both <i>in vitro</i> and <i>in vivo</i>. The results demonstrated that iron
chelator loaded therapeutic nanoparticles could reverse functional
deficits in Parkinsonian mice not only physiologically but also behaviorally.
On the contrary, both untreated PD mice and non-TAT anchored nanoparticle
treated PD mice showed similar loss in DA neurons and difficulties
in behaviors. Therefore, with protection of zwitterionic polymer and
prolonged <i>in vivo</i> lifetime, iron chelator loaded
nanoparticles with delayed saturation provide a PD phenotype reversion
therapy and significantly improve the living quality of the Parkinsonian
mice
Low Temperature and Template-Free Synthesis of Hollow Hydroxy Zinc Phosphate Nanospheres and Their Application in Drug Delivery
Hollow
hydroxy zinc phosphate nanospheres (HZnPNSs) with sizes
of 30–50 nm and wall thicknesses of about 7 nm were synthesized
using a template-free method through wet precipitation of ZnÂ(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O and (NH<sub>4</sub>)<sub>2</sub>HPO<sub>4</sub> at temperatures of 0, 10, and 20 °C.
The crystal structures, morphologies, sizes and pore properties, Zn/P
molar ratios, and thermal stability properties of nanoparticles have
been carefully examined. The methyl-thiotetrazole assay measurements
proved the low cell cytotoxicity of the material. The protein adsorption
of negatively charged bovine serum albumin (BSA) and positively charged
lysozyme on HZnPNSs was also investigated. The results showed that
HZnPNSs had high protein adsorption affinity. Furthermore, anticancer
doxorubicin as a model drug was used to evaluate the entrapment efficiency
and drug loading capacity of HZnPNSs, which showed high loading capacity
(>16 wt %) for doxorubicin. The confocal laser scanning microscope
observations showed that the drug could be efficiently delivered into
cells
Toward Scalable Fabrication of Hierarchical Silica Capsules with Integrated Micro-, Meso-, and Macropores
Hierarchical porous structures are ubiquitous in biological organisms and inorganic systems. Although such structures have been replicated, designed, and fabricated, they are often inferior to naturally occurring analogues. Apart from the complexity and multiple functionalities developed by the biological systems, the controllable and scalable production of hierarchically porous structures and building blocks remains a technological challenge. Herein, a facile and scalable approach is developed to fabricate hierarchical hollow spheres with integrated micro-, meso-, and macropores ranging from 1 nm to 100 μm (spanning five orders of magnitude). (Macro)molecules, micro-rods (which play a key role for the creation of robust capsules), and emulsion droplets have been successfully employed as multiple length scale templates, allowing the creation of hierarchical porous macrospheres. Thanks to their specific mechanical strength, these hierarchical porous spheres could be incorporated and assembled as higher level building blocks in various novel materials
Real-Time Monitoring of Anticancer Drug Release with Highly Fluorescent Star-Conjugated Copolymer as a Drug Carrier
Chemotherapy is one of the major
systemic treatments for cancer,
in which the drug release kinetics is a key factor for drug delivery.
In the present work, a versatile fluorescence-based real-time monitoring
system for intracellular drug release has been developed. First, two
kinds of star-conjugated copolymers with different connections (e.g.,
pH-responsive acylhydrazone and stable ether) between a hyperbranched
conjugated polymer (HCP) core and many linear polyÂ(ethylene glycol)
(PEG) arms were synthesized. Owing to the amphiphilic three-dimensional
architecture, the star-conjugated copolymers could self-assemble into
multimicelle aggregates from unimolecular micelles with excellent
emission performance in the aqueous medium. When doxorubicin (DOX)
as a model drug was encapsulated into copolymer micelles, the emission
of star-conjugated copolymer and DOX was quenched. In vitro biological
studies revealed that fluorescent intensities of both star-conjugated
copolymer and DOX were activated when the drug was released from copolymeric
micelles, resulting in the enhanced cellular proliferation inhibition
against cancer cells. Importantly, pH-responsive feature of the star-conjugated
copolymer with acylhydrazone linkage exhibited accelerated DOX release
at a mildly acidic environment, because of the fast breakage of acylhydrazone
in endosome or lysosome of tumor cells. Such fluorescent star-conjugated
copolymers may open up new perspectives to real-time study of drug
release kinetics of polymeric drug delivery systems for cancer therapy