Xue Ke

Hepatocellular carcinoma dually-targeted nanoparticles for reduction triggered intracellular delivery of doxorubicin.

Hepatocellular carcinoma (HCC) dual targeted stimuli responsive nanoparticles (NPs) for intracellular delivery of doxorubicin (DOX) were developed based on a reduction cleavable hyaluronic acid-glycyrrhetinic acid conjugate (HA-Cyst-GA). HA-Cyst-GA conjugate readily formed NPs in aqueous milieu and exhibited a high drug loading capacity (33.9%). The NPs redox responsiveness evaluation showed a tendency to lose their structural integrity in response to a reductive stimulus while remaining stable at physiological conditions, and that drug release was dramatically accelerated in presence of an intracellular level of glutathione. Moreover, cellular uptake studies highlighted the affinity of hepatoma cells (HepG2) toward the NPs as compared to breast cancer cells (MDA-MB-231). HA-Cyst-GA DOX-NPs displayed an increased cytotoxic potency over their non-responsive counterparts and free DOX with IC50 of 5.75, 9.33 and 10.23μg/mL, respectively. CLSM observations showed that HA-Cyst-GA DOX-NPs mediated a faster intracellular release and nuclear delivery of DOX as compared to the insensitive control. In vivo imaging study performed on H22 tumor bearing mice revealed a selective accumulation of DiR labeled NPs in the tumor and liver upon systemic administration. The antitumor efficacy was evaluated in HepG2 tumor xenograft model. Overall HA-Cyst-GA NPs appear as a potential HCC targeted intracellular delivery platform for DOX.

Near-infrared light triggered drug delivery system for higher efficacy of combined chemo-photothermal treatment.

The combination of chemotherapy and photothermal therapy is a promising strategy for cancer treatment. In the present study, indocyanine green (ICG), a widely used near-infrared (NIR) dye in photothermal therapy, and chemotherapeutic drug-doxorubicin (DOX) were loaded within the nanoparticles of novel designed arylboronic ester and cholesterol modified hyaluronic acid (PPE-Chol1-HA), denoted as PCH-DI. We take advantage of reactive oxygen species (ROS) production capability of ICG and ROS-sensitivity of arylboronic ester to realize controllable drug release. It was confirmed that PCH-DI exhibited remarkable photothermal effect and light-triggered faster release of DOX with NIR laser irradiation. DOX in PCH-DI/Laser group exhibited the most efficient nucleus binding toward HCT-116 colon cells in vitro. Furthermore, enhanced cytotoxicity and promoted tumor growth suppression effect of PCH-DI on HCT-116 tumor xenograft nude mice and AOM-induced murine orthotopic colorectal cancer model was achieved under NIR laser irradiation. Thus, the co-delivery system based on PCH appears to be a promising platform for the combined chemo-photothermal therapy in tumor treatment. STATEMENT OF SIGNIFICANCE In case of chemo-photothermal combination therapy, the synchronism of treatments plays an important role in achieving expected antitumor efficiency. In this study, a light triggered ROS mediated drug delivery system was developed with the help of ROS-sensitive moieties of arylboronic ester and ROS producer of ICG. We innovatively make use of the ROS production capability of ICG under NIR laser irradiation to promote a faster release of DOX resulting from swelling of PCH-DI due to the presence of arylboronic ester. Intracellular ROS detection demonstrated that ROS level of PCH-I increased under irradiation. Moreover, the faster release behavior of DOX from PCH-DI with NIR laser irradiation was confirmed by the in vitro drug release and cellular uptake study. Meanwhile, local hyperthermia was verified by photothermal effect tests. Therefore, the synchronism of the combination therapy was achieved via light triggered faster release of DOX (chemo-therapy) and local hyperthermia (thermal-therapy) using PCH-DI under irradiation. It was reasonable to attribute the efficient anti-tumor efficiency of PCH-DI both in vitro and in vivo to the enhanced synergistic effect of chemo-photothermal combination therapy with realization of synchronism. To this end, this novel co-delivery system has provided a promising solution for achieving the synchronism of treatment to strengthen the efficiency of combination therapy.

The anti-tumor performance of docetaxel liposomes surface-modified with glycyrrhetinic acid

Purpose: Anti-tumor performance of docetaxel liposomes surface-modified with glycyrrhetinic acid (GA-DX-Lip) as a new hepatocytes-targeted delivery vehicle was investigated, unmodified docetaxel liposome (DX-Lip) was chosen as a comparison. Methods: GA-DX-Lip was prepared by film dispersion method. The physicochemical properties were characterized. The cellular uptake mechanism of GA-modified liposomes was studied in hepatocytes and nonparenchymal cells. Pharmacokinetics and the anti-tumor activity in vitro and in vivo of GA-DX-Lip were investigated. Results: The size of GA-DX-Lip was about 90 nm with negative charge and the entrapment efficiency was more than 95%. GA-modified liposomes had the specific receptor-mediated cellular endocytosis to hepatocytes, and the uptake ratio of hepatocytes to nonparenchymal cells was 2.28 times. The tumor inhibitory ratio of GA-DX-Lip in vitro was 2.03 times of DX-Lip, the T/C of GA-DX-Lip was 20.14%, better than the 33.27% of DX-Lip. There was no obvious difference in pharmacokinetics parameters. Discussion and Conclusion: The preliminary cellular uptake test showed the receptor-mediated endocytosis and enhanced hepatocytes-target for GA-modified liposomes. Compared with the unmodified liposome, GA-DX-Lip possessed better anti-tumor activity and unchanged pharmacokinetic behavior. The present results suggest that the GA-modified liposomes may be a promising delivery system for hepatocytes-target.

A low-molecular-weight heparin-coated doxorubicin-liposome for the prevention of melanoma metastasis

Abstract Tumor metastasis is the biggest challenge in cancer therapy. During the metastasis process, metastatic cells could acquire stealth ability toward immune system through the formation of a protection cloak by hijacking platelets (PTs). Heparins, a heterogeneous mixture of glycosaminoglycans, can inhibit metastatic cascades by blocking P-selectin-mediated intercellular adhesion between tumor cells and PTs. In this study, low-molecular-weight heparin-coated doxorubicin-loaded liposome (LMWH-DOX-Lip) was developed for metastasis preventative therapy. The formation of LMWH-DOX-Lip was based on electrostatic interactions between the negatively charged heparins and cationic lipids. LMWH-DOX-Lip prepared at the optimum prescription possessed high entrapment efficiency, ideal particle size and zeta potential. Morphology of LMWH-DOX-Lip was characterized by atomic force microscopy and transmission electron microscopy. The results of confocal microscopic observations and flow cytometry analysis indicated that LMWH-DOX-Lip mediated an efficient cellular uptake in B16F10 melanoma cell line. Besides, LMWH-DOX-Lip displayed an increased cytotoxic over their unmodified counterparts. Furthermore, the inhibition effect of LMWH-DOX-Lip on adhesion between tumor cells and PTs/P-selectin was observed. In vivo study performed on a pulmonary melanoma mouse model revealed a substantially tumor metastasis prevention by LMWH-DOX-Lip. All these results suggested that LMWH-DOX-Lip could significantly inhibit metastasis through preventing the tumor cell–platelet interactions and in the meantime suppressed tumor growth.

Application of Carrier and Plasticizer to Improve the Dissolution and Bioavailability of Poorly Water-Soluble Baicalein by Hot Melt Extrusion

AbstractThe objective of this study was to develop a suitable formulation for baicalein (a poorly water-soluble drug exhibiting high melting point) to prepare solid dispersions using hot melt extrusion (HME). Proper carriers and plasticizers were selected by calculating the Hansen solubility parameters, evaluating melting processing condition, and measuring the solubility of obtained melts. The characteristic of solid dispersions prepared by HME was evaluated. The dissolution performance of the extrudates was compared to the pure drug and the physical mixtures. Physicochemical properties of the extrudates were characterized by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Relative bioavailability after oral administration in beagle dogs was assessed. As a result, Kollidon VA64 and Eudragit EPO were selected as two carriers; Cremophor RH was used as the plasticizer. The dissolution of all the extrudates was significantly improved. DSC and PXRD results suggested that baicalein in the extrudates was amorphous. FTIR spectroscopy revealed the interaction between drug and polymers. After oral administration, the relative bioavailability of solid dispersions with VA64 and EPO was comparative, about 2.4- and 2.9-fold greater compared to the pure drug, respectively. Figureᅟ

The microstructure characterization of meloxicam microemulsion and its influence on the solubilization capacity

Objective: The aim of this study was to characterize the microstructure of microemulsion consisting of oleic acid, Cremophor RH40, ethanol, and water (Km = 2), and investigate the influence of microstructure on the solubilization potential of the microemulsion to meloxicam (MLX). Methods: Pseudo-ternary phase diagrams of microemulsion were constructed using the H2O titration method. The microstructures of microemulsion on dilution line N91 were identified by means of conductivity, viscosity, surface tension, and density. The freeze-fracture electron microscopy proved the specific microstructure. Differential scanning calorimetry (DSC) was used to evaluate the position of MLX in microemulsion, and the solubility of MLX in chosen microemulsions on dilution line N91 was measured. Results: The three microstructures along dilution line N91, including water-in-oil (W/O), bicontinuous (BC), and oil-in-water (O/W) microemulsion, were characterized. The solubilization capacity of W/O microemulsion is the best, compared with the other two, whereas the O/W is the weakest. A possible structure model has been applied for the explanation of difference. Conclusions: The solubilization capacity of microemulsion is closely related with its microstructure.

A wogonin-loaded glycyrrhetinic acid-modified liposome for hepatic targeting with anti-tumor effects

Abstract Liver cancer has become one of the most common fatal cancers worldwide, with morbidity rates increasing each year. Wogonin (WG) is an attractive candidate for the development of new anti-cancer drugs. In this study, a novel glycyrrhetinic acid (GA)-modified WG liposome was developed for use in targeted anti-cancer therapy. Three types of WG preparations were investigated: free wogonin in solution (WG), passively targeted wogonin liposomes (WG-Lip) and GA-modified wogonin liposomes (GA-WG-Lip). The entrapment efficiency, size and zeta potential were measured. Cellular uptake, cytotoxicity, in vivo bio-distribution and anti-tumor efficacy were also investigated. Addition of GA to the liposomes did not diminish the high entrapment efficiency observed in the liposomes without GA. GA-WG-Lip showed the greatest uptake and had an IC50 value 1.46 times higher than that of WG-Lip. The GA-modified liposomes rapidly accumulated in the liver with a long retention time, and also displayed a better tumor inhibitory ratio than that of the unmodified liposomes. Overall, the data indicated that use of the GA-modified WG liposomes conferred improvements in bio-distribution, accumulation at the tumor and therapeutic efficacy, perhaps due to increased receptor-mediated uptake of liposomes by liver-targeted cells. Together, these data show that GA-WG-Lip is a promising means of targeted therapy for liver cancer.

GE11 peptide modified and reduction-responsive hyaluronic acid-based nanoparticles induced higher efficacy of doxorubicin for breast carcinoma therapy

Novel breast carcinoma dual-targeted redox-responsive nanoparticles (NPs) based on cholesteryl-hyaluronic acid conjugates were designed for intracellular delivery of the antitumor drug doxorubicin (DOX). A series of reduction-responsive hyaluronic acid derivatives grafted with hydrophobic cholesteryl moiety (HA-ss-Chol) and GE11 peptide conjugated HA-ss-Chol (GE11–HA-ss-Chol) were synthesized. The obtained conjugates showed attractive self-assembly characteristics and high drug loading capacity. GE11–HA-ss-Chol NPs were highly stable under conditions mimicking normal physiological conditions, while showing a fast degradation of the vehicle’s structure and accelerating the drug release dramatically in the presence of intracellular reductive environment. Furthermore, the cellular uptake assay confirmed GE11–HA-ss-Chol NPs were taken up by MDA-MB-231 cells through CD44- and epidermal growth factor receptor-mediated endocytosis. The internalization pathways of GE11–HA-ss-Chol NPs might involve clathrin-mediated endocytosis and macropinocytosis. The intracellular distribution of DOX in GE11–HA-ss-Chol NPs showed a faster release and more efficient nuclear delivery than the insensitive control. Enhanced in vitro cytotoxicity of GE11–HA-ss-Chol DOX-NPs further confirmed the superiority of their dual-targeting and redox-responsive capacity. Moreover, in vivo imaging investigation in MDA-MB-231 tumor-bearing mice confirmed that GE11–HA-ss-Chol NPs labeled with 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindotricarbocyanine iodide, a near-infrared fluorescence dye, possessed a preferable tumor accumulation ability as compared to the single-targeting counterpart (HA-ss-Chol NPs). The antitumor efficacy showed an improved therapy efficacy and lower systemic side effect. These results suggest GE11–HA-ss-Chol NPs provide a good potential platform for antitumor drugs.

Reduction-responsive modification-induced higher efficiency for attenuation of tumor metastasis of low molecular weight heparin functionalized liposomes

For oncotherapy, a delivery system that can effectively prevent and attenuate tumor metastasis is greatly desirable. Herein, we report a novel delivery system of liposomal doxorubicin with a reduction-responsive modification of low molecular weight heparin (LMWH) to realize higher efficacy in the prevention of tumor metastasis. A series of DOX liposomal formulations of crude DOX-Lip, reduction-insensitive LMWH-DOX-Lip and reduction-responsive LMWH-ss-DOX-Lip were prepared. The reduction-responsive modification of DOX liposomes with LMWH chains resulted in higher cellular uptake, higher cytotoxicity of DOX and higher anti-invasion and anti-migration abilities of LMWH compared with reduction-insensitive liposomes, owing to the fast release of DOX and LMWH in the tumor cytoplasm. Meanwhile, the evaluation of heparanase expression was also adopted to reveal the possible underlying mechanism of the effects of LMWH on the attenuation of tumor metastasis. In vivo pulmonary melanoma metastasis assays confirmed the enhanced drug efficacy and lower side effects of LMWH-ss-DOX-Lip compared with crude DOX-Lip or the reduction-insensitive control group. These results may be attributed to the rational design of the drug carriers with a synergistic combination of LMWH moieties and DOX loaded liposomes via reduction-responsive modification.

Interconversion Studies of Betamethasone Acetate Polymorphs

ABSTRACT The polymorph interconversions of Betamethasone Acetate (BA) were studied under various pharmaceutical conditions, such as grinding, heating and suspending in water, based on differential scanning calorimetry, thermogravimetric analysis, and X-ray powder diffraction. There existed enantiotropic relationships between the three polymorphs of BA, which were named form II, Iα, and Iβ work, respectively. It was concluded that form II was the most stable form when suspended in water.