Lingzhi Zhao

Hollow silica nanoparticles loaded with hydrophobic phthalocyanine for near-infrared photodynamic and photothermal combination therapy.

Owing to the convenience and minimal invasiveness, phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), is emerging as a powerful technique for cancer treatment. To date, however, few examples of combination PDT and PTT have been reported. Phthalocyanine (Pc) is a class of traditional photosensitizer for PDT, but its bioapplication is limited by high hydrophobicity. In this present study, hollow silica nanospheres (HSNs) were employed to endow the hydrophobic phthalocyanine with water-dispersity, and the as-prepared hollow silica nanoparticles loaded with hydrophobic phthalocyanine (Pc@HSNs) exhibits highly efficient dual PDT and PTT effects. In vitro and in vivo experimental results clearly indicated that the dual phototherapeutic effect of Pc@HSNs can kill cancer cells or eradicate tumor tissues. This multifunctional nanomedicine may be useful for PTT/PDT treatment of cancer.

Polyphosphoric acid capping radioactive/upconverting NaLuF4:Yb,Tm,153Sm nanoparticles for blood pool imaging in vivo

Nanoparticles that circulate in the bloodstream for a prolonged period of time have important biomedicine applications. However, no example of lanthanide-based nanoparticles having a long-term circulation bloodstream has been reported to date. Herein, we report on difunctional radioactive and upconversion nanoparticles (UCNP) coated with polyphosphoric acid ligand, that is ethylenediamine tetramethylenephosphonic acid (EDTMP), for an application in single-photon emission computed tomography (SPECT) blood pool imaging. The structure, size and zeta-potential of the EDTMP-coated nanoparticles (EDTMP-UCNP) are verified using transmission electron microscopy and dynamic light scattering. Injection of radioisotope samarium-153-labeled EDTMP-UCNP (EDTMP-UCNP:(153)Sm) into mice reveal superior circulation time compared to control nanoparticles coated with citric acid (cit-UCNP:(153)Sm) and (153)Sm complex of EDTMP (EDTMP-(153)Sm). The mechanism for the extended circulation time may be attributed to the adhesion of EDTMP-UCNP on the membrane of red blood cells (RBCs). In vivo toxicity results show no toxicity of EDTMP-UCNP at the dose of 100 mg/kg, validating its safety as an agent for blood pool imaging. Our results provide a new strategy of nanoprobe for a long-term circulation bloodstream by introducing polyphosphoric acid as surface ligand.

Yolk-shell upconversion nanocomposites for LRET sensing of cysteine/homocysteine.

The fabrication of lanthanide upconversion nanocomposites as probes has become a new research hotspot due to its special advantages via utilizing upconversion luminescence (UCL) as a detection signal. Herein, a hybrid organic dye modified upconversion nanophosphor is successfully developed as a nanoprobe for cysteine/homocysteine. Yolk-shell structured upconversion nanoparticles (YSUCNP) with lanthanide upconversion nanophosphor as moveable core and silica as mesoporous shell are synthesized, and a colorimetric chemodosimeter for cysteine/homocysteine is accommodated in the hollow cavities. Thus, cysteine/homocysteine can be quantitatively detected on the basis of luminescent resonance energy transfer (LRET) in a UCL turn-off pattern. The dye-loaded YSUCNP possess good dispersibility in aqueous solution; thus detection of the targeted molecule can be achieved in pure water. Cellular experiments carried out with laser-scanning upconversion luminescence microscopy further demonstrate that the dye-loaded YSUCNP can serve as an intracellular nanoprobe to detect cysteine/homocysteine. Moreover, this dye-loading protocol can be developed as a common approach to construct other chemodosimeter-modified UCNP hybrid nanoprobes, as proved by a UCL turn-on style sensor for cyanide.

Visible-light-excited and europium-emissive nanoparticles for highly-luminescent bioimaging in vivo.

Europium(III)-based material showing special milliseconds photoluminescence lifetime has been considered as an ideal time-gated luminescence probe for bioimaging, but is still limited in application in luminescent small-animal bioimaging inxa0vivo. Here, a water-soluble, stable, highly-luminescent nanosystem, Ir-Eu-MSN (MSNxa0=xa0mesoporous silica nanoparticles, Ir-Euxa0=xa0[Ir(dfppy)2(pic-OH)]3Eu·2H2O, dfppyxa0=xa02-(2,4-difluorophenyl)pyridine, pic-OHxa0=xa03-hydroxy-2-carboxypyridine), was developed by an in situ coordination reaction to form an insoluble dinuclear iridium(III) complex-sensitized-europium(III) emissive complex within mesoporous silica nanoparticles (MSNs) which had high loading efficiency. Compared with the usual approach of physical adsorption, this in-situ reaction strategy provided 20-fold the loading efficiency (43.2%) of the insoluble Ir-Eu complex in MSNs. These nanoparticles in solid state showed bright red luminescence with high quantum yield of 55.2%, and the excitation window extended up to 470xa0nm. These Ir-Eu-MSN nanoparticles were used for luminescence imaging in living cells under excitation at 458xa0nm with confocal microscopy, which was confirmed by flow cytometry. Furthermore, the Ir-Eu-MSN nanoparticles were successfully applied into high-contrast luminescent lymphatic imaging inxa0vivo under low power density excitation of 5xa0mWxa0cm(-2). This synthetic method provides a universal strategy of combining hydrophobic complexes with hydrophilic MSNs for inxa0vivo bioimaging.

Imaging-Guided Drug Release from Glutathione-Responsive Supramolecular Porphysome Nanovesicles

Drug delivery systems that can be employed to load anticancer drugs and release them triggered by a specific stimulus, such as glutathione, are of great importance in cancer therapy. In this study, supramolecular porphysome nanovesicles that were self-assembled by amphiphilic porphyrin derivatives were successfully constructed, mainly driven by the π-π stacking, hydrogen bonding, and hydrophobic interactions, and were used as carriers of anticancer drugs. The nanovesicles are monodispersed in shape and uniform in size. The drug loading and in vitro drug release investigations indicate that these nanovesicles are able to encapsulate doxorubicin (DOX) to achieve DOX-loaded nanovesicles, and the nanovesicles could particularly release the loaded drug triggered by a high concentration of glutathione (GSH). More importantly, the drug release in cancer cells could be monitored by fluorescent recovery of the porphyrin derivative. Cytotoxicity experiments show that the DOX-loaded nanovesicles possess comparable therapeutic effect to cancer cells as free DOX. This study presents a new strategy in the fabrication of versatile anticancer drug nanocarriers with stimuli-responsive properties. Thus, the porphysome nanovesicles demonstrated here might offer an opportunity to bridge the gap between intelligent drug delivery systems and imaging-guided drug release.

Remarkable In Vivo Nonlinear Photoacoustic Imaging Based on Near-Infrared Organic Dyes.

Two near-infrared dyes featuring good dispersion and light-harvesting property present a remarkable nonlinear photoacoustic response in vitro and in vivo comparing with conventional gold nanorods. This study benefits the fabrication of drug delivery platforms with accurate targeting and control effect under photoacoustic image guidance.

Responsive Prodrug Self-Assembled Vesicles for Targeted Chemotherapy in Combination with Intracellular Imaging

Targeted drug delivery systems having controlled drug release property with an inherent fluorescence reporter have drawn a lot of attention in nanomedicine. However, only very few prodrugs can be directly used to construct such delivery systems. Herein, we report that an amphiphilic chlorambucil-based prodrug consisting of a fluorescence reporter and a d-mannose targeting ligand could directly self-assemble into glutathione-responsive nanovesicles for selective cancer therapy and intracellular imaging. These nanovesicles could be dissociated to release the chlorambucil drug with obviously red-shifted fluorescence when internalized by d-mannose receptor-overexpressed MCF-7 cancer cells. In addition, the nanovesicles displayed better selectivity and higher therapy efficiency than free chlorambucil drug.

Host–Guest Interaction‐Mediated Construction of Hydrogels and Nanovesicles for Drug Delivery

Hand-in-hand or head-to-head: A novel naphthalimide derivative is successfully designed and synthesized, which can self-assemble to produce hydrogels. When injecting this compound into CB[8] solution, the nanovesicles are obtained with a narrow size distribution. The cytotoxicity assay confirms that doxorubicin-loaded nanocarriers show therapeutic effects to cancer cells.