Abstract
A disturbance of reactive oxygen species (ROS) homeostasis may cause the pathogenesis of many diseases. Inspired by natural photosynthesis, this work proposes a photo-driven H
2
-evolving ...liposomal nanoplatform (Lip NP) that comprises an upconversion nanoparticle (UCNP) that is conjugated with gold nanoparticles (AuNPs) via a ROS-responsive linker, which is encapsulated inside the liposomal system in which the lipid bilayer embeds chlorophyll
a
(Chl
a
). The UCNP functions as a transducer, converting NIR light into upconversion luminescence for simultaneous imaging and therapy in situ. Functioning as light-harvesting antennas, AuNPs are used to detect the local concentration of ROS for FRET biosensing, while the Chl
a
activates the photosynthesis of H
2
gas to scavenge local excess ROS. The results thus obtained indicate the potential of using the Lip NPs in the analysis of biological tissues, restoring their ROS homeostasis, possibly preventing the initiation and progression of diseases.
A facile, robust approach to the synthesis of Au cubic nanoframes is described. The synthesis involves three major steps: 1) preparation of Au–Ag alloyed nanocages using a galvanic replacement ...reaction between Ag nanocubes and HAuCl4; 2) deposition of thin layers of pure Au onto the surfaces of the nanocages by reducing HAuCl4 with ascorbic acid, and; 3) formation of Au cubic nanoframes through a dealloying process with HAuCl4. The key to the formation of Au cubic nanoframes is to coat the surfaces of the Au–Ag nanocages with sufficiently thick layers of Au before they are dealloyed. The Au layer could prevent the skeleton of a nanocage from being fragmented during the dealloying step. The as‐prepared Au cubic nanoframes exhibit tunable localized surface plasmon resonance peaks in the near‐infrared region, but with much lower Ag content as compared with the initial Au–Ag nanocages.
Cubic nanoframes of Au are synthesized by integrating galvanic replacement with deposition of Au and dealloying of Ag. The as‐prepared cubic nanoframes exhibit tunable localized surface plasmon resonance peaks in the near‐infrared region, but with much lower Ag content as compared with the conventional Au–Ag nanocages.
Cerenkov luminescence imaging based on light emission from the decay of radionuclides has recently drawn great interest in molecular imaging. In this paper, we report for the first time the Cerenkov ...luminescence phenomenon of 198Au isotope, as well as a facile route to the preparation of radioluminescent Au nanocages without additional radiolabeling or dye conjugation. The specific radioactivity of the Au nanocages could be easily and precisely controlled by varying the concentration of H198AuCl4 precursor used for the galvanic replacement reaction. The direct incorporation of 198Au atoms into the structure of Au nanocages enabled the ability of accurate analysis and real-time imaging in vivo. Furthermore, under biological conditions the radioactive Au nanocages were shown to emit light with wavelengths in the visible and near-infrared regions, enabling luminescence imaging of the whole mice in vivo, as well as the organs ex vivo. When combined with their favorable scattering and absorption properties in the near-infrared region, the radioactive Au nanocages can serve as a new platform for multimodality imaging and will have a significant impact on both small animal and clinical imaging.
Gold nanohexapods represent a novel class of optically tunable nanostructures consisting of an octahedral core and six arms grown on its vertices. By controlling the length of the arms, their ...localized surface plasmon resonance peaks could be tuned from the visible to the near-infrared region for deep penetration of light into soft tissues. Herein we compare the in vitro and in vivo capabilities of Au nanohexapods as photothermal transducers for theranostic applications by benchmarking against those of Au nanorods and nanocages. While all these Au nanostructures could absorb and convert near-infrared light into heat, Au nanohexapods exhibited the highest cellular uptake and the lowest cytotoxicity in vitro for both the as-prepared and PEGylated nanostructures. In vivo pharmacokinetic studies showed that the PEGylated Au nanohexapods had significant blood circulation and tumor accumulation in a mouse breast cancer model. Following photothermal treatment, substantial heat was produced in situ and the tumor metabolism was greatly reduced for all these Au nanostructures, as determined with 18F-flourodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Combined together, we can conclude that Au nanohexapods are promising candidates for cancer theranostics in terms of both photothermal destruction and contrast-enhanced diagnosis.
Sorafenib is a tyrosine kinase inhibitor that has recently been shown to be a potential antifibrotic agent. However, a narrow therapeutic window limits the clinical use and therapeutic efficacy of ...sorafenib. Herein, we have developed and optimized nanoparticle (NP) formulations prepared from a mixture of poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (PEG-PLGA) copolymers with poly(lactic-co-glycolic acid) (PLGA) for the systemic delivery of sorafenib into the fibrotic livers of CCl4-induced fibrosis mouse models. We characterized and compared the pharmaceutical and biological properties of two different PLGA nanoparticles (NPs) — PEG-PLGA NPs (PEG-PLGA/PLGA=10/0) and PEG-PLGA/PLGA NPs (PEG-PLGA/PLGA=5/5). Increasing the PLGA content in the PEG-PLGA/PLGA mixture led to increases in the particle size and drug encapsulation efficacy and a decrease in the drug release rate. Both PEG-PLGA and PEG-PLGA/PLGA NPs significantly prolonged the blood circulation of the cargo and increased the uptake by the fibrotic livers. The systemic administration of PEG-PLGA or PEG-PLGA/PLGA NPs containing sorafenib twice per week for a period of 4weeks efficiently ameliorated liver fibrosis, as indicated by decreased α-smooth muscle actin (α-SMA) content and collagen production in the livers of CCl4-treated mice. Furthermore, sorafenib-loaded PLGA NPs significantly shrank the abnormal blood vessels and decreased microvascular density (MVD), leading to vessel normalization in the fibrotic livers. In conclusion, our results reflect the clinical potential of sorafenib-loaded PLGA NPs for the prevention and treatment of liver fibrosis.
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Ceria (CeO2) hollow fibers with Pt nanoparticles (Pt NPs) embedded in their inner surfaces were prepared by sequentially depositing Pt NPs and CeO2 sheaths on electrospun fibers of polystyrene, ...followed by calcination in air at 400 °C. Despite a relatively low Pt loading in this system, the turnover frequency for CO oxidation was 2–3 orders of magnitude higher than those of other systems, and the reactivity was also stable up to 700 °C.
Convenient, rapid, and accurate detection of chemical and biomolecules would be a great benefit to medical, pharmaceutical, and environmental sciences. Many chemical and biosensors based on metal ...nanoparticles (NPs) have been developed. However, as a result of the inconvenience and complexity of most of the current preparation techniques, surface plasmon-based test papers are not as common as, for example, litmus paper, which finds daily use. In this paper, we propose a convenient and practical technique, based on the photothermal effect, to fabricate the plasmonic test paper. This technique is superior to other reported methods for its rapid fabrication time (a few seconds), large-area throughput, selectivity in the positioning of the NPs, and the capability of preparing NP arrays in high density on various paper substrates. In addition to their low cost, portability, flexibility, and biodegradability, plasmonic test paper can be burned after detecting contagious biomolecules, making them safe and eco-friendly.
In this study, the phenomenon of light trapping in Si solar cells coated with metal (Au) and dielectric (TiO2, SiO2) nanoparticles (NPs) is systematically investigated. In contrast to previous ...reports, herein it is proposed that the photocurrent enhancement of solar cells should be attributed to the limited antireflection ability of the Au NP arrays. In other words, the Au NP arrays might not enhance the absorption of the active layer in cells when no light is reflected from the air–substrate interface. Therefore, the Au NPs are replaced with dielectric NPs, which possess lower extinction coefficients, and then the antireflection property of the TiO2 NP arrays is optimized. A simple, rapid, and cheap solution‐based method is used to prepare close‐packed TiO2 NP films on Si solar cells; these devices exhibit a uniform and remarkable increase (ca. 30%) in their photocurrents. To the best of the authors’ knowledge, this uniform photocurrent enhancement is greater than those obtained from previously reported metal and dielectric NP–enhanced Si wafer‐based solar cells.
The phenomenon of light trapping in Si solar cells coated with nanoparticles (NPs) is systematically investigated. Au NP arrays could be considered as deficient single‐layer antireflection coatings: they could reduce the amount of reflected light, scattering it into the Si substrates, while strongly absorbing incident light. Therefore, the Au NPs are replaced with TiO2 NPs, which possess lower extinction coefficients.
Aims: Cranioplasty and ventriculoperitoneal shunt (VPS) are common procedures for patients who undergo decompressive craniectomy. The ideal time for these two procedures remains controversial.
...Settings and Design: This is a retrospective, single institute, chart review comparing the complications associated with simultaneous and staged cranioplasty and VPS.
Materials and Methods: From January 2012 to December 2017, 56 patients who underwent both cranioplasty and VPS surgery at our hospital were separated into simultaneous or staged operation groups. We compared the demographic data and complications, including infections, subdural or epidural hemorrhage, and revision surgery between the groups.
Statistical Analysis Used: Independent Student's t-test was used for analysis of continuous variables, and Fisher's exact test was used for categorical data. MedCalc (version: 18.11) was used to perform all analysis.
Results: Nineteen patients underwent simultaneous cranioplasty and VPS, whereas 37 underwent staged operation. Etiologies for craniectomy included traumatic brain injury, infarction, spontaneous subarachnoid hemorrhage, and spontaneous intracerebral hemorrhage. There were no significant differences in the baseline characteristics between the groups. The overall complication rate was 14.3%. Three (15.8%) patients experienced complications in the simultaneous group: One (5.3%) with skin infection and two (10.5%) with overdrainage. Five (13.5%) patients experienced complications in the staged group: three (10.8%) with skin infections, one with central nervous system (CNS) infections, and one with both skin and CNS infections. Overall complications, wound infections, CNS infections, overdrainage, and revision surgery showed no significant differences between the groups.
Conclusions: Simultaneous cranioplasty and VPS showed complication rates similar to those of staged operation.
In this paper, we report the optical constants (refractive index, extinction coefficient) of self-assembled hollow gold nanoparticle (HGN) monolayers determined through spectroscopic ellipsometry ...(SE). We prepared a series of HGNs exhibiting various morphologies and surface plasmon resonance (SPR) properties. The extinction coefficient (k) curves of the HGN monolayers exhibited strong SPR peaks located at wavelengths that followed similar trends to those of the SPR positions of the HGNs in solution. The refractive index (n) curves exhibited an abnormal dispersion that was due to the strong SPR extinction. The values of Δn and k max both correlated linearly with the particle number densities. From a comparison of the optical constant values of HGNs with those of solid Au nanoparticles (NPs), we used SE measurements to demonstrate a highly sensitive Si-based chemical sensor. HGNs display a slightly lower value of k at the SPR peak but a much higher sensitivity to changes in the surrounding medium than do solid Au NPs.
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