Chenyang Wei

Computed tomography imaging-guided radiotherapy by targeting upconversion nanocubes with significant imaging and radiosensitization enhancements

The clinical potentials of radiotherapy could not be achieved completely because of the inaccurate positioning and inherent radioresistance of tumours. In this study, a novel active-targeting upconversion theranostic agent (arginine-glycine-aspartic acid-labelled BaYbF5: 2% Er3+ nanocube) was developed for the first time to address these clinical demands. Heavy metal-based nanocubes (~10 nm) are potential theranostic agents with bifunctional features: computed tomography (CT) contrast agents for targeted tumour imaging and irradiation dose enhancers in tumours during radiotherapy. Remarkably, they showed low toxicity and excellent performance in active-targeting CT imaging and CT imaging-guided radiosensitizing therapy, which could greatly concentrate and enlarge the irradiation dose deposition in tumours to enhance therapeutic efficacy and minimize the damage to surrounding tissues.

Mesoporous carbon@silicon-silica nanotheranostics for synchronous delivery of insoluble drugs and luminescence imaging

A hierarchical theranostic nanostructure with carbon and Si nanocrystals respectively encapsulated in the mesopores and within the framework of mesoporous silica nanoparticles (CS-MSNs) was constructed by a bottom-up self-assembly strategy combining an in situ one-step carbonization/crystallization approach. CS-MSNs exhibited narrow size distribution, high payload of insoluble drugs and unique NIR-to-Vis luminescence imaging feature. The bio-conjugated CS-MSNs with a PEGylated phospholipid compound and hyaluronic acid showed excellent dispersivity and could specifically target cancer cells overexpressing CD44, deliver insoluble drugs into these cells and consequently kill them effectively, and also fluorescently image them simultaneously in a unique and attractive NIR-to-Vis luminescence imaging fashion, providing a promising opportunity for cancer theranostics.

One-step synthesis of sulfur doped graphene foam for oxygen reduction reactions

Sulfur doped graphene foam has been successfully synthesized by a simple solve-thermal method, which exhibited a much enhanced oxygen reduction reaction (ORR) catalytic activity as well as an especially high electrochemical stability, and would be a promising non-metal cathode catalyst for the ORR.

A facile synthesis of versatile Cu2-xS nanoprobe for enhanced MRI and infrared thermal/photoacoustic multimodal imaging.

A novel type of intelligent nanoprobe by using single component of Cu2-xS for multimodal imaging has been facilely and rapidly synthesized in scale via thermal decomposition followed by biomimetic phospholipid modification, which endows them with uniform and small nanoparticle size (ca.15 nm), well phosphate buffer saline (PBS) dispersity, high stability, and excellent biocompatibility. The as-synthesized Cu2-xS nanoprobes (Cu2-xS NPs) are capable of providing contrast enhancement for T1-weighted magnetic resonance imaging (MRI), as demonstrated by the both in vitro and in vivo imaging investigations for the first time. In addition, due to their strong near infrared (NIR) optical absorption, they can also serve as a candidate contrast agent for enhanced infrared thermal/photoacoustic imaging, to meet the shortfalls of MRI. Hence, complementary and potentially more comprehensive information can be acquired for the early detection and accurate diagnosis of cancer. Furthermore, negligible systematic side effects to the blood and tissue were observed in a relatively long period of 3 months. The distinctive multimodal imaging capability with excellent hemo/histocompatibility of the Cu2-xS NPs could open up a new molecular imaging possibility for detecting and diagnosing cancer or other diseases in the future.

Highly dispersed Au nanoparticles incorporated mesoporous TiO2 thin films with ultrahigh Au content

Highly dispersed gold nanoparticles (NPs) incorporated mesoporous titania thin films with ultrahigh Au content (53.3 wt%) were synthesized by a deposition-precipitation method using urea as precipitator, which showed high off-resonant third-order optical nonlinear susceptibility (χ(3) = 2.69 × 10−8 esu) measured by the Z-scan technique at 1064 nm. The enhanced χ(3) value of the materials was attributed to the homogeneous dispersion and the ultrahigh concentration of the gold NPs, and the high linear refractive index of the titania matrix.

Low-temperature one-step synthesis of covalently chelated ZnO/dopamine hybrid nanoparticles and their optical properties

Dopamine covalently chelated ZnO nanoparticles were synthesized by a nonaqueous one-step chemical process at a temperature as low as 60 °C. The formation of ZnO/dopamine hybrid structure was proved by x-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) techniques. Detailed absorption, luminescence, and time-resolved decay studies were performed for these ZnO/dopamine hybrid nanoparticles. We observed an enhanced green emission, which could be assigned to a new band-gap emission based on the fast of nanosecond lifetime of the green emission. Our results demonstrated that the change of optical properties of ZnO nanoparticles after covalently chelated by dopamine ligands is closely associated with the formation of new band structure.

One-step replication and enhanced catalytic activity for cathodic oxygen reduction of the mesostructured Co3O4/carbon composites

Mesostructured Co3O4/C composites of high surface area have been synthesized via a one-step replica route by co-nanocasting cobalt and carbon precursors into mesoporous silica, in which the Co3O4 nanoparticles are homogeneously dispersed in the mesoporous structure of carbon substrates. The mesostructured composites showed relatively high catalytic activities for oxygen reduction reaction (ORR), and that with a Co loading content of 4.3 at% exhibited the best electrochemical performance for ORR. The relatively high catalytic activity is attributed to the effects of the redox couples (Co(3+)/Co(2+)) together with the contribution from the conductive mesoporous carbon substrate.

Facile synthesis of liposome/Cu 2-x S-based nanocomposite for multimodal imaging and photothermal therapy

A kind of multifunctional perfluoropentane (PFP) and ultrasmall Cu2−xS nanodots (u-Cu2−xS NDs) co-incorporated liposome (PFP@ u-Cu2−xS NDs@liposome) nanocomposite has been facilely and successfully synthesized for enhanced ultrasound/infrared thermal/photoacoustic multimodal imaging and photothermal therapy upon near infrared (NIR) laser irradiation. Such a liposome-based nanocomposite possesses a number of advantages, such as high dispersity and stability, excellent biocompatibility, small particle size (<100 nm), well-defined core/shell structure, strong NIR absorption and photo-triggered vaporization of PFP, etc. The detailed in vitro investigations demonstrate that the as-synthesized PFP@ u-Cu2−xS NDs@ liposome nanocomposite is capable of enhancing the contrasts of ultrasound/infrared thermal/photoacoustic multimodal imaging, and substantially improving the photothermal therapeutic efficacy. This novel liposome-based theranostic nanoplatform shows great potentials in the future cancer diagnosis and therapy.摘要包裹氟碳化合物的脂质体已被广泛用作超声成像造影剂; 而硫化铜由于具有表面等离子体共振效应在近红外区域具有强光学吸收特性, 可以同时作为一种性能优异的近红外热/光声成像造影剂和光热治疗剂. 本文以有机脂质体为载体, 同时包裹氟碳化合物和硫化铜, 在近红外激光照射下, 硫化铜吸收光能将其转化为热能, 达到氟碳化合物的相变温度时使氟碳化合物 由液态变为气态, 产生的气泡可增强超声成像造影能力, 从而构建了单一波长激光诱导的超声/近红外热/光声多模式成像引导下的光热治疗, 极大提高了癌症治疗的安全性和治疗效率. 体外实验结果表明该有机无机复合物不仅能克服单纯有机脂质体的不稳定性等缺点, 而且具有显著增强的多模式成像造影能力和优异的光热治疗效果, 具有重要的临床应用前景.

Au nanoparticles incorporated mesoporous silica thin films with a high Au content: preparation and third-order optical non-linearity

Au nanoparticles incorporated in mesoporous silica thin films with a high Au content 29.2 wt% were prepared, which demonstrated a higher off-resonance third-order non-linear optical susceptibility (chi(3)=8.23x10(-10) esu).

Hollow mesoporous carbon cubes with high activity towards the electrocatalytic reduction of oxygen.

Hollow-structured mesoporous carbon cubes (HMCCs) have been successfully synthesized from carbon dioxide by a facile approach based on thermal reduction of magnesium. The approach is economical and applicable to large-scale synthesis. Notably, pyrrole-type nitrogen species are doped into the HMCCs during the synthesis in situ, that is, without introducing a nitrogen-containing precursor. A formation mechanism of the HMCCs is proposed, and formation of the structure is attributed to MgO templates generated in situ. Furthermore, the HMCCs are demonstrated to be a promising alternative to commercial Pt/C fuel-cell catalysts for the electrochemical oxygen reduction reaction.