Ruo-Jing Li

Dual-targeting daunorubicin liposomes improve the therapeutic efficacy of brain glioma in animals

Chemotherapy for brain glioma has been of limited value due to the inability of transport of drug across the blood-brain barrier (BBB) and poor penetration of drug into the tumor. For overcoming these hurdles, the dual-targeting daunorubicin liposomes were developed by conjugating with p-aminophenyl-alpha-D-manno-pyranoside (MAN) and transferrin (TF) for transporting drug across the BBB and then targeting brain glioma. The dual-targeting effects were evaluated on the BBB model in vitro, C6 glioma cells in vitro, avascular C6 glioma tumor spheroids in vitro, and C6 glioma-bearing rats in vivo, respectively. After applying dual-targeting daunorubicin liposomes, the transport ratio across the BBB model was significantly increased up to 24.9%. The most significant uptake by C6 glioma was evidenced by flow cytometry and confocal microscope. The C6 glioma spheroid volume ratio was significantly lowered to 54.7%. The inhibitory rate to C6 glioma cells after crossing the BBB was significantly enhanced up to 64.0%. The median survival time of tumor bearing rats after administering dual-targeting daunorubicin liposomes (22 days) was significantly longer than that after giving free daunorubicin (17 days, P=0.001) or other controls. In conclusion, the dual-targeting daunorubicin liposomes are able to improve the therapeutic efficacy of brain glioma in vitro and in animals.

The use of mitochondrial targeting resveratrol liposomes modified with a dequalinium polyethylene glycol-distearoylphosphatidyl ethanolamine conjugate to induce apoptosis in resistant lung cancer cells

Intrinsic multidrug resistance (MDR) of cancers remains a major obstacle to successful chemotherapy. A dequalinium polyethylene glycol-distearoylphosphatidylethanolamine (DQA-PEG(2000)-DSPE) conjugate was synthesized as a mitochondriotropic molecule, and mitochondrial targeting resveratrol liposomes were developed by modifying DQA-PEG(2000)-DSPE on the surface of liposomes for overcoming the resistance. Evaluations were performed on the human lung adenocarcinoma A549 cells and resistant A549/cDDP cells, A549 and A549/cDDP tumor spheroids as well as the xenografted resistant A549/cDDP cancers in nude mice. The yield of DQA-PEG(2000)-DSPE conjugate synthesized was about 87% and the particle size of mitochondrial targeting resveratrol liposomes was approximately 70 nm. The mitochondrial targeting liposomes significantly enhanced the cellular uptake, and selectively accumulated into mitochondria when encapsulating coumarin as the fluorescent probe. Furthermore, mitochondrial targeting resveratrol liposomes induced apoptosis of both non-resistant and resistant cancer cells by dissipating mitochondria membrane potential, releasing cytochrome c and increasing the activities of caspase 9 and 3. They also exhibited significant antitumor efficacy in two kinds of cancer cells, in tumor spheroids by penetrating deeply into the core, and in xenografted resistant A549/cDDP cancers in nude mice. Mitochondrial targeting resveratrol liposomes co-treating with vinorelbine liposomes significantly enhanced the anticancer efficacy against the resistant A549/cDDP cells. In conclusion, mitochondrial targeting resveratrol liposomes would provide a potential strategy to treat the intrinsic resistant lung cancers by inducing apoptosis via mitochondria signaling pathway.

Mitochondrial targeting liposomes incorporating daunorubicin and quinacrine for treatment of relapsed breast cancer arising from cancer stem cells

Breast cancer stem cells play a crucial role in the relapse of breast cancers because they are resistant to a standard chemotherapy and the residual cancer stem cells are able to proliferate indefinitely. The objectives of present study were to construct a kind of mitochondrial targeting daunorubicin plus quinacrine liposomes for treating and for preventing the recurrence of breast cancer arising from the cancer stem cells. MCF-7 cancer stem cells were identified as CD44(+)/CD24(-) cells and cultured in free-serum medium. Evaluations were performed on MCF-7 cancer stem cells, MCF-7 cancer stem cell mammospheres, and the relapsed tumor by xenografting MCF-7 cancer stem cells into female NOD/SCID mice. The particle size of mitochondrial targeting daunorubicin plus quinacrine liposomes was approximately 98 nm. The mitochondrial targeting liposomes evidently increased the mitochondrial uptake of drugs, were selectively accumulated into mitochondria, activated the pro-apoptotic Bax protein, dissipated the mitochondrial membrane potential, opened the mitochondrial permeability transition pores, released cytochrome C by translocation, and initiated a cascade of caspase 9 and 3 reactions, thereby inducing apoptosis of MCF-7 cancer stem cells. The mitochondrial targeting liposomes showed the strongest efficacy in treating MCF-7 cancer cells in vitro, in treating MCF-7 cancer stem cells in vitro, and in treating the relapsed tumor in mice. Mitochondrial targeting daunorubicin plus quinacrine liposomes would provide a new strategy for treating and preventing the relapse of breast cancers arising from cancer stem cells.

All-trans retinoic acid stealth liposomes prevent the relapse of breast cancer arising from the cancer stem cells.

The relapse of cancer is mostly due to the proliferation of cancer stem cells which could not be eliminated by a standard chemotherapy. A new kind of all-trans retinoic acid stealth liposomes was developed for preventing the relapse of breast cancer and for treating the cancer in combination with a cytotoxic agent, vinorelbine stealth liposomes. In vitro studies were performed on the human breast cancer MCF-7 and MDA-MB-231 cells. In vivo evaluations were performed on the newly established relapse model with breast cancer stem cells. Results showed that the particle size of all-trans retinoic acid stealth liposomes was approximately 80nm, and the encapsulation efficiency was >90%. Breast cancer stem cells were identified with the CD44(+)/CD24(-) phenotype and characterized with properties: resistant to cytotoxic agent, stronger capability of proliferation, and stronger capability of differentiation. Inhibitory effect of all-trans retinoic acid stealth liposomes was more potent in cancer stem cells than in cancer cells. The mechanisms were defined to be two aspects: arresting breast cancer stem cells at the G(0)/G(1) phase in mitosis, and inducing the differentiation of breast cancer stem cells. The cancer relapse model was successfully established by xenografting breast cancer stem cells into NOD/SCID mice, and the formation and growth of the xenografted tumors were significantly inhibited by all-trans retinoic acid stealth liposomes. The combination therapy of all-trans retinoic acid stealth liposomes with vinorelbine stealth liposomes produced the strongest inhibitory effect to the relapse tumor model. It could be concluded that all-trans retinoic acid stealth liposomes could be used for preventing the relapse of breast cancer by differentiating cancer stem cells and arresting the cell-cycle, and for treating breast cancer as a co-therapy, thus providing a novel strategy for treating breast cancer and preventing relapse derived from breast cancer stem cells.

Mitochondrial targeting topotecan-loaded liposomes for treating drug-resistant breast cancer and inhibiting invasive metastases of melanoma

Multidrug resistance and cancer metastases are two obstacles to a successful chemotherapy and metastases are closely associated with drug resistance. Mitochondrial targeting topotecan-loaded liposomes have been developed to overcome this resistance and resistance-related metastases. Investigations were performed on breast cancer MCF-7 and resistant MCF-7/adr cells, MCF-7 and resistant MCF-7/adr tumor spheroids, resistant MCF-7/adr cell xenografts in nude mice, and a naturally resistant B16 melanoma metastatic model in nude mice. The mitochondrial targeting topotecan-loaded liposomes were approximately 64 nm in size, and exhibited the strongest inhibitory effects on MCF-7 cells and resistant MCF-7/adr cells. Mitochondrial targeting effects were demonstrated by co-localization in mitochondria, enhanced drug content in mitochondria, dissipated mitochondrial membrane potential, opening of mitochondrial permeability transition pores, release of cytochrome C, and activation of caspase 9 and 3. The targeting liposomes had a stronger inhibitory effect on the resistant tumor spheroids in vitro, enhanced accumulation in resistant MCF-7/adr cell xenografts in mice, as well as being very effective on resistant MCF-7/adr cell xenografts in mice, and having a marked anti-metastastic effect on the naturally resistant B16 melanoma metastatic model in mice. In conclusion, mitochondrial targeting topotecan-loaded liposomes could be a promising strategy for treating resistant cancers and resistance-related metastases.

Enhanced efficacy of functionalized epirubicin liposomes in treating brain glioma-bearing rats.

PURPOSE The restriction of drug transporting across the blood-brain barrier (BBB) and the limit of drug penetrating into the tumor tissue remain the major obstacles for brain tumor chemotherapy. In the present study, we developed a functionalized liposomal nanoconstruct, epirubicin liposomes modified with tamoxifen (TAM) and transferrin (TF), for transporting drug across the BBB and afterwards targeting the brain glioma. METHODS Evaluations were performed on the murine C6 glioma cells, the C6 glioma spheroids, the BBB model in vitro and the brain glioma-bearing rats. RESULTS When compared with controls, epirubicin liposomes modified with TAM and TF showed the strongest inhibitory effect to C6 glioma cells or glioma spheroids in vitro, significant transport ability across the BBB model in vitro, an evident effect of targeting the brain tumor cells in vitro, and an extended median survival time in the brain glioma-bearing rats. CONCLUSION Epirubicin liposomes modified with TAM and TF significantly improve the therapeutic efficacy of brain glioma in vitro and in animals, hence providing a new strategy for brain tumor chemotherapy.

Targeting therapy with mitosomal daunorubicin plus amlodipine has the potential to circumvent intrinsic resistant breast cancer.

Intrinsic resistance of cancers is a major cause of failure in chemotherapy. We proposed here a strategy to overcome intrinsic resistance by constructing cancer cell mitochondria-specifically targeting drug-loaded liposomes, namely, mitosomal daunorubicin plus amlodipine. Anticancer agent daunorubicin and apoptotic inducer amlodipine were loaded together into the mitosomes, and targeting molecule dequalinium was modified on the surface. Evaluations were performed on the breast cancer MCF-7 and resistant MCF-7/adr cells and in animals. Mitosomal daunorubicin plus amlodipine were about 97 nm, selectively accumulated in mitochondria, induced the swelling and disruption of mitochondria, dissipated the mitochondrial membrane potential, released a large amount of cytochrome C by translocation, cleaved Bid, and initiated a cascade of caspase 8 and 3 reactions. A robust anticancer effect was evidenced in vivo. Mitochondria-specifically targeting drug-loaded liposomes would provide a new strategy for treating resistant cancers.

The efficacy of mitochondrial targeting antiresistant epirubicin liposomes in treating resistant leukemia in animals

Background Multidrug resistance (MDR) of cancers can be circumvented by inducing programmed cell death, which is known as apoptosis. Mitochondria play a crucial role in apoptosis. Mitochondria-specific therapy would provide an efficient strategy for treating resistant cancers. Design and methods A strategy was proposed here to overcome MDR by designing cancer mitochondria-specific drug-loaded liposomes, namely, antiresistant epirubicin mitosomes, aimed at treating resistant leukemia by targeting mitochondria. Evaluations were performed on human chronic leukemia K562, MDR K562/ADR cells, and female BALB/c nude mice xenografted with MDR K562/ADR cells. The liposomes were characterized through assays of cytotoxicity, mitochondrial targeting, caspase-9 and caspase-3, antitumor activities, and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) analysis. Results The average size of antiresistant epirubicin mitosomes was in the range of 105–115 nm. Antiresistant epirubicin mitosomes were effective in inhibiting proliferation of MDR K562/ADR cells in vitro and selectively accumulated into the mitochondria. Caspase-9 and caspase-3 activity was increased after applying antiresistant epirubicin mitosomes. In xenografted resistant MDR K562/ADR tumor in nude mice, antiresistant tumor effect of antiresistant epirubicin mitosomes was evidently observed. Apoptotic inducing effects by antiresistant epirubicin mitosomes were noticeably evidenced via mitochondrial pathway. Conclusions Antiresistant epirubicin mitosomes had significant inhibitory effect against resistant leukemia in vitro and in vivo, hence providing a promising strategy for improving therapeutic efficacy in resistant human leukemia.

Separation of injectable salidroside by column chromatography of macroporous resins for treating myocardial ischemia

The objective of the present study is to develop a method for large-scale separating and purifying salidroside from rhodiola kirilowii roots and for preparing injectable medicinal ingredient. Crude extract of salidroside was prepared by water-ethanol system, and purified by column chromatography of macroporous resins. Static adsorption and desorption studies were performed on six kinds of macroporous resins, and SP825 resin was chosen, followed by optimizing process parameters. The optimum sample volume, feed concentration, ratio of diameter to height, and feeding flow rate were 1.5 bed volumes (BV), 15 mg/mL, 1:10 and 1 BV/h, respectively. Dynamic desorption was performed consecutively with 8 BV of distilled water, 3 BV of 5% ethanol and 8 BV of 10% ethanol at a flow rate of 2 BV/h. After three cycles in separating 3.5 tons of rhodiola kirilowii roots, salidroside purity was increased from 3.4% in the crude extract to 93.6% in purified salidroside product. This study provides a novel method to separate salidroside for injectable use.