Prussian blue nanosphere-embedded hydrogel for photothermal therapy by peritumoral administration

To establish an injectable hydrogel containing Prussian blue (PB) nanospheres for photothermal therapy against cancer, PB nanospheres were prepared by one-pot synthesis and the thermosensitive Pluronic F127 was used as the hydrogel matrix. The PB nanospheres and the hydrogel were characterized by shape, particle size, serum stability, photothermal performance upon repeated 808 nm laser irradiation, as well as the rheological features. The effect of the PB nanospheres and the hydrogel were evaluated qualitatively and quantitatively in 4T1 mouse breast cancer cells. The retention, photothermal efficacy, therapeutic effects and systemic toxicity of the hydrogel were assessed in a tumor-bearing mouse model. The PB nanospheres had a diameter of about 150 nm and exhibited satisfactory serum stability, photo-heat convert ability and repeated laser exposure stability. The hydrogel encapsulation did not negatively influence the above features of the photothermal agent. The nanosphere-containing hydrogel showed a phase transition at body temperature and, as a result, a long retention time . The photothermal agent-embedded hydrogel displayed promising photothermal therapeutic effects in the tumor-bearing mouse model with little-to-no systemic toxicity after peritumoral administration.

Synthesis of a novel long-circulating dual-receptor targeting and dual-modal molecular probe：an in-vitro study / 中华放射学杂志

Objective To explore a novel long-circulating dual-receptor targeting and dual-modal molecular probe and investigate its physicochemical properties and targeting effect on breast cancer cells in vitro. Methods Dual-receptor targeting and dual-modal molecular probe RGD@BBN-lipo(QDs)-SPIO was synthesized in the following steps: long-circulating liposome was prepared by film dispersion method;water-soluble superparamagnetic iron oxide (SPIO) nanoparticles and Quantum dots (QDs) were loaded in the hydrophilic and hydrophobic layer of liposome, respectively;RGD and BBN polypeptides were coupled on the former functional magnetic/fluorescent liposomes. Stability of the probe in different physiological solutions was investigated. Transmission electron microscopy (TEM) and particle size analyzer were used to measure nanoparticle sizes and the Zeta potential. Characterization of RGD and BBN was investigated through 1H-NMR and elemental analysis. The MRI T2 relaxivities (1/T2) of RGD@BBN-lipo(QDs)-SPIO was measured through T2 map scanning on 3.0 T MR system. HUV-EC-C cells were used for assessment of cells viability by MTS assay. Prussian blue staining and fluorescence imaging were carried out to determine the targeted breast cellular uptake of RGD@BBN-lipo(QDs)-SPIO nanoparticles. Results The targeting magnetic/fluorescent dual-model molecular probes appeared spherical or para-spherical,with a mean diameter of(118.2±3.9)nm,Zeta potential of (-24.78±1.68) mV,MR T2 magnetic relaxation rate of 0.498 1× 106 M-1 · s-1.RGD and BBN polypeptides were successfully coupled on the former functionally magnetic/fluorescent liposomes with the bind rates of 33.05%and 45.06%, respectively. There was low cytotoxity of the molecular probe on human umbilical vein endothelical cells(HUV-EC-C)by MTS study. Prussian blue staining and fluorescence imaging studies showed that the RGD@BBN-lipo(QDs)-SPIO nanoparticles could target any αvβ3 or gastrin releasing peptide receptor overexpression breast cancer. Conclusions RGD@BBN-lipo(QDs)-SPIO is a novel long-circulating dual-receptor targeting and dual-modal molecular probe and has excellent physicochemical properties and stability, high T2 relaxivities and strong targeting effect on cancer cells and has laid a solid foundation for early diagnosis of breast cancer.

In vitro targeting effect of lactoferrin modified PEGylated liposomes for hepatoma cells / 药学学报

A lactoferrin-containing PEGylated liposome system (Lf-PLS) was developed and tested in vitro as a hepatoma-targeting drug delivery system. PEGylated liposomes (PLS) were successfully prepared using the thin film hydration method with peglipid post insertion. Lf was covalently conjugated onto the carboxyl terminal of DSPE-PEG2000-COOH on liposomes. Coumarin-6 was used to trace Lf-PLS with fluorescence. The cellular uptake of this system was carried out in asialoglycoprotein receptor (ASGPR) positive HepG2 cells via confocal microscopy and flow cytometry. The Lf-PLS liposome was observed as spherical or oval vesicles with the particle size around 130 nm, zeta potential about -30 mV and encapsulation efficiency more than 80%. The confocal microscopy images and flow cytometry data demonstrated that Lf-PLS resulted in significantly higher cell association by ASGPR positive HepG2 cells compared to PLS. The association between Lf-PLS and cells were dependent on the concentration, time and temperature, which was inhibited by pre-incubation with excessive free Lf. The results suggest that Lf-PLS has a good targeting effect on HepG2 cells in vitro. The targeting mechanism may be related to the specific binding of Lf and ASGPR on HepG2 cells, which guides Lf-PLS to the cell surface to induce an active endocytosis process. All these results demonstrated that Lf-PLS might be a potential drug delivery system in targeting hepatocellular carcinoma, which deserves more research on its targeting ability, antitumor efficiency, and metabolism in vivo for treatment of hepatomacellular carcinoma.

Comparative pharmacokinetics of tetramethylpyrazine phosphate in rat plasma and extracellular fluid of brain after intranasal, intragastric and intravenous administration

The purpose of this study was to compare the pharmacokinetic profiles of tetramethylpyrazine phosphate (TMPP) in plasma and extracellular fluid of the cerebral cortex of rats via three delivery routes: intranasal (i.n.), intragastric (i.g.) and intravenous (i.v.) administration. After i.n., i.g. and i.v. administration of a single-dose at 10 mg/kg, cerebral cortex dialysates and plasma samples drawn from the carotid artery were collected at timed intervals. The concentration of TMPP in the samples was analyzed by HPLC. The area under the concentration-time curve (AUC) and the ratio of the AUCbrain to the AUCplasma (drug targeting efficiency, DTE) was calculated to evaluate the brain targeting efficiency of the drug via these different routes of administration. After i.n. administration, TMPP was rapidly absorbed to reach its peak plasma concentration within 5 min and showed a delayed uptake into cerebral cortex (t max=15 min). The ratio of the AUCbrain dialysates value between i.n. route and i.v. injection was 0.68, which was greater than that obtained after i.g. administration (0.43). The systemic bioavailability obtained with i.n. administration was greater than that obtained by the i.g. route (86.33% vs. 50.39%), whereas the DTE of the nasal route was 78.89%, close to that of oral administration (85.69%). These results indicate that TMPP is rapidly absorbed from the nasal mucosa into the systemic circulation, and then crosses the blood-brain barrier (BBB) to reach the cerebral cortex. Intranasal administration of TMPP could be a promising alternative to intravenous and oral approaches.