Antitumor Activity of α-Linolenic Acid-Paclitaxel Conjugate Nanoparticles: In vitro and in vivo.

PURPOSE: Small molecule modified antitumor drug conjugate nanoparticles have the advantages of high drug loading, simple synthesis and preparation, and better biocompatibility. Due to the large demand for exogenous α-linolenic acid (ALA) by tumor cells, we synthesized α-linolenic acid-paclitaxel conjugate (ALA-PTX) and prepared α-linolenic acid-paclitaxel conjugate nanoparticles (ALA-PTX NPs), in order to obtain better tumor cellular uptake and antitumor activity in vitro and in vivo. METHODS: We synthesized and characterized ALA-PTX, and then prepared and characterized ALA-PTX NPs. The cellular uptake, uptake pathways, intracellular behavior, in vitro and in vivo antitumor activity of ALA-PTX NPs were evaluated. RESULTS: The size of ALA-PTX NPs was approximately 110.7±1.7 nm. The drug loading was approximately 90% (w/w) with CrEL-free and organic solvent-free characteristics. The cellular uptake of ALA-PTX NPs was significantly higher than that of PTX injection by MCF-7, MCF-7/ADR and HepG2 cells. In these three cell lines, the cellular uptake of ALA-PTX NPs at 6h was approximately 1.5-2.6 times higher than that of PTX injection. ALA-PTX NPs were ingested through clathrin-mediated endocytosis, then transferred to lysosomes, and could dissolve in cells to play an antitumor activity. The in vitro and in vivo antitumor activity of ALA-PTX NPs was confirmed in MCF-7/ADR and HepG2 cell models and tumor-bearing nude mouse models. CONCLUSION: ALA-PTX NPs developed in our study could provide a new method for the preparation of nano-delivery systems suitable for antitumor therapy that could increase tumor cellular uptake and enhance antitumor activity.

RANK/RANKL Acts as a Protective Factor by Targeting Cholangiocytes in Primary Biliary Cholangitis.

BACKGROUND: Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by the highly selective autoimmune injury of small intrahepatic bile ducts. Studies reported that the cholangiocytes from PBC patients expressed significantly higher levels of both receptor activator of nuclear factor-kappa B (RANK) and its ligand RANKL. However, the accurate role of RANK/RANKL axis in PBC remains unclear. METHODS: Forty patients with PBC were enrolled according to the inclusion criteria. The biochemical parameters (alkaline phosphatase, ALP; gamma-glutamyltransferase, GGT; alanine aminotransferase, ALT; aspartate transaminase, AST; total bilirubin, TB) were collected at baseline and followed-up after 6 months of treatment with ursodeoxycholic acid (UDCA, 15 mg/kg d). Stages of PBC were diagnosed based on liver biopsy histopathology according to Nakanuma's criteria. RANK expression in hepatic tissues was detected by immunohistochemistry. The cellular immunofluorescence method was used to locate the distribution of RANK in the human intrahepatic biliary epithelial cells (HIBECs) cultured in vitro. HIBECs were treated with RANKL at a concentration of 100 ng/ml or transfected with RANK-overexpressing lentivirus (LV-RANK). CCK-8 assay and cell cycle assay were used to detect the cell proliferation. Real-time PCR was used to detect the expression of IL-6, E-cadherin, VCAM, ICAM-1, TNF-α, and CD80. RESULTS: RANK expression in liver biopsies from early PBC patients (stage I + stage II) was significantly lower than that from advanced PBC patients (stage III + stage IV) (1.7 ± 0.63 vs. 2.3 ± 0.45 scores, P < 0.05). High-RANK patients seemed to have better response to UDCA than low-RANK patients (88.9% vs. 40.9%, P < 0.05). The baseline biochemical parameters between the two groups were comparable. The decline percentages of ALP and GGT after UDCA treatment were more obvious in high-RANK patients than those in low-RANK patients (53.90% ± 9.82% vs. 23.93% ± 6.24%, P < 0.05; 74.11% ± 7.18% vs. 48.00% ± 8.17%, P < 0.05, respectively). HIBECs proliferation was significantly inhibited after treatment of RANKL or transfection with LV-RANK. Increased expression of IL-6 and E-cadherin was observed in HIBECs treated with RANKL or LV-RANK. CONCLUSION: The overall hepatic RANK expression was associated with disease severity and biochemical response in PBC patients. Activation of RANK/RANKL signaling pathway inhibited cholangiocytes proliferation in vitro. Our study suggested that RANK/RANKL pathway might be a potential target of immunotherapy of PBC based on its involvement in the occurrence and development of the disease.

Antitumor activity of the bioreductive prodrug 3-(2-nitrophenyl) propionic acid-paclitaxel nanoparticles (NPPA-PTX NPs) on MDA-MB-231 cells: in vitro and in vivo.

BACKGROUND: 3-(2-Nitrophenyl) propionic acid-paclitaxel (NPPA-PTX) is a paclitaxel (PTX) bioreductive prodrug synthesized by our lab. We hypothesize that NPPA-PTX can self-assemble to form nanoparticles (NPs). MATERIALS AND METHODS: In the present research, the theoretical partition coefficient (XlogP) and Hansen solubility parameters of NPPA-PTX were calculated. NPPA-PTX nanoparticles prepared by NPPA-PTX and DSPE-PEG (NPPA-PTX:DSPE-PEG =1:0.1, w/w) (NPPA-PTX@PEG NPs) were prepared and characterized. The cellular uptake, in vitro antitumor activity, in vivo targeting effect, tumor distribution, in vivo antitumor activity, and safety of NPPA-PTX@PEG NPs were investigated. RESULTS: Our results indicate that NPPA-PTX can self-assemble to form NPPA-PTX@PEG NPs. Both the cellular uptake and safety of NPPA-PTX@PEG NPs were higher than those of Taxol. NPPA-PTX@PEG NPs could target tumor tissues by a passive targeting effect. In tumor tissues, NPPA-PTX@PEG NPs could completely transform into active PTX. The in vivo antitumor activity of NPPA-PTX@PEG NPs was confirmed in MDA-MB-231 tumor-bearing nude mice. CONCLUSION: The bioreductive prodrug NPPA-PTX could self-assemble to form NPs. The safety and antitumor activity of NPPA-PTX@PEG were confirmed in our in vitro and in vivo experiments. The NPPA-PTX@PEG NPs developed in this study could offer a new way of preparing bioreductive prodrug, self-assembled NPs suitable for antitumor therapy.

Anti-tumour activity of low molecular weight heparin doxorubicin nanoparticles for histone H1 high-expressive prostate cancer PC-3M cells.

Nucleus-targeting drug delivery systems (NTDDs) deliver chemotherapeutic agents to nuclei in order to improve the efficacy of anti-tumour therapy. Histone H1 (H1) plays a key role in establishing and maintaining higher order chromatin structures and could bind to cell membranes. In the present study, we selected H1 as a target to prepare a novel H1-mediated NTDD. Low molecular weight heparin (LMHP) and doxorubicin (DOX) were combined to form LMHP-DOX. Then, a novel NTDD consisting of LMHP-DOX nanoparticles (LMHP-DOX NPs) was prepared by self-assembly. The characteristics of LMHP-DOX and LMHP-DOX NPs were investigated. Histone H1 high-expressive prostate cancer PC-3M cell line was selected as the cell model. Cellular uptake, and the in vitro and in vivo anti-tumour activity of LMHP-DOX NPs were evaluated on H1 high-expressive human prostate cancer PC-3M cells. Our results indicated that intact LMHP-DOX NPs mediated by H1 could be absorbed by H1 high-expressive PC-3M cells, escape from the lysosomes to the cytoplasm, and localize in the perinuclear region via H1-mediated, whereby DOX could directly enter the cell nucleus and quickly increase the concentration of DOX in the nuclei of H1 high-expressive PC-3M cells to enhance the apoptotic activity of cancer cells. The anti-coagulant activity of LMHP-DOX NPs was almost completely diminished in rat blood compared with that of LMHP, indicating the safety of LMHP-DOX NPs. Compared to traditional NTDD strategies, LMHP-DOX NPs avoid the complicated modification of nucleus-targeting ligands and provide a compelling solution for the substantially enhanced nuclear uptake of chemotherapeutic agents for the development of more intelligent NTDDs.

The theranostic efficiency of tumor-specific, pH-responsive, peptide-modified, liposome-containing paclitaxel and superparamagnetic iron oxide nanoparticles.

BACKGROUND: In the present study, the tumor-specific, pH-responsive peptide H7K(R2)2-modified, theranostic liposome-containing paclitaxel (PTX) and superparamagnetic iron oxide nanoparticles (SPIO NPs), PTX/SPIO-SSL-H7K(R2)2, was prepared by using H7K(R2)2 as the targeting ligand, SPIO NPs as the magnetic resonance imaging (MRI) agent, PTX as antitumor drug. METHODS: The PTX/SPIO-SSL-H7K(R2)2 was prepared by a thin film hydration method. The characteristics of PTX/SPIO-SSL-H7K(R2)2 were evaluated. The targeting effect, MRI, and antitumor activity of PTX/SPIO-SSL-H7K(R2)2 were investigated detail in vitro and in vivo in human breast carcinoma MDA-MB-231 cell models. RESULTS: Our results of in vitro flow cytometry, in vivo imaging, and in vivo MR imaging confirmed the pH-responsive characteristic of H7K(R2)2 in MDA-MB-231 cell line in vitro and in vivo. The results of in vivo MRI and in vivo antitumor activity confirmed the theranostic effect of PTX/SPIO-SSL-H7K(R2)2 in MDA-MB-231 tumor-bearing model. CONCLUSION: Considering all our in vitro and in vivo results, we conclude that we developed targeting modified theranostic liposome which could achieve both role of antitumor and MRI.

Effect of XlogP and Hansen Solubility Parameters on Small Molecule Modified Paclitaxel Anticancer Drug Conjugates Self-Assembled into Nanoparticles.

Small molecule modified anticancer drug conjugates (SMMDCs) can self-assemble into nanoparticles (NPs) as therapeutic NP platforms for cancer treatment. Here we demonstrate that the XlogP and Hansen solubility parameters of paclitaxel (PTX) SMMDCs is essential for SMMDCs self-assembling into NPs. The amorphous state of PTX SMMDCs will also affect SMMDCs self-assembling into NPs. However, the antitumor activity of these PTX SMMDCs NPs decreased along with their XlogP values, indicating that a suitable XlogP value for designing the SMMDCs is important for self-assembling into NPs and for possessing antitumor activity. For higher level XlogP SMMDCs, a degradable linker should be considered in the design of SMMDCs to overcome the problem of lower antitumor activity. It is preferable that the hydrophilic groups in the SMMDCs should be present on the surface of self-assembling NPs.

Comparative Effectiveness of Prophylactic Strategies for Perinatal Transmission of Hepatitis B Virus: A Network Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Perinatal transmission is the main route of hepatitis B virus (HBV) transmission. While several measures have been attempted as means of preventing perinatal HBV transmission, the optimal strategy remains inconclusive. METHODS: We conducted a comprehensive search, through December 2016, for randomized controlled trials (RCTs) that compared the following measures among pregnant women with HBV infection: placebo/none, active immunoprophylaxis (hepatitis B vaccine series starting at birth [HBVac]), passive-active immunoprophylaxis (hepatitis B immunoglobulin and vaccine [HBIG+HBVac]), prenatal HBIG administration (HBIG/HBIG+HBVac), and prenatal antiviral therapy (AVT/HBIG+HBVac). Direct, indirect, and network meta-analyses were performed for all treatment comparisons. RESULTS: Fifteen RCTs involving 2706 infants of HBV carrier mothers were eligible for analysis. Network meta-analysis demonstrated similar results as direct and indirect comparisons. HBVac alone significantly reduced the risk of hepatitis B infection in infants of HBV carrier mothers (relative risk [RR], 0.32; 95% confidence interval [CI], 0.21-0.50). The combination of immunoglobulin with vaccine is superior to vaccine alone (RR, 0.37; 95% CI, 0.20-0.67). Prenatal HBIG administration and antiviral therapy offer further advantages over current passive-active immunoprophylaxis for infants of highly viremic (HBV DNA level higher than 2 × 105 IU/mL) mothers (RR, 0.47; 95% CI, 0.29-0.75; and RR, 0.31; 95% CI, 0.10-0.99, respectively). There was no significant publication bias. CONCLUSIONS: Based on the universal infantile vaccination program, HBIG for infants born to HBV carrier mothers further reduces transmission. For highly viremic mothers whose children are still at risk for transmission under current immunoprophylaxis, prenatal HBIG administration or antiviral therapy in late pregnancy may be considered if more long-term evidence supports its efficacy and safety.

Clinical course and perinatal transmission of chronic hepatitis B during pregnancy: A real-world prospective cohort study.

OBJECTIVE: To determine the clinical course and perinatal transmission of chronic hepatitis B during pregnancy in a real life setting. METHODS: A total of 221 singleton pregnant women with detectable HBV-DNA levels (≥103 copies/mL) were enrolled during January 2011 to June 2015. Forty-three high viraemic patients (≥106 copies/mL) received telbivudine in the 2nd or 3rd trimester according to their intention, while 89 high viraemic and 79 low viraemic (≥103 and <106 copies/mL) patients were the control cohorts. Primary endpoint was the pregnancy outcomes and secondary endpoint the perinatal transmission including intrauterine infection, immunoprophylaxis failure and occult infection. RESULTS: In all, 209 patients completed pregnancy with 209 infants, while 2 in telbivudine-treated cohort had unexplained late stillbirths. Twenty-nine (70.7%) of telbivudine-treated patients and 3 (3.4%) of untreated high viraemic controls achieved undetectable HBV-DNA levels prior delivery. At 7 months postpartum, immunoprophylaxis failure was significantly lower (2.4%) in telbivudine-treated cohort, compared with 16.9% and 10.1% in untreated high and low viraemic cohorts, respectively. CONCLUSIONS: Low viraemic patients may also need antiviral therapy since they bear moderate risk for perinatal transmission of HBV. However, more multicenter, large-scale studies are required before antepartum antiviral therapy is routinely recommended in patients with detectable viral loads.

[Effect of rapid eye movement sleep deprivation on anxiety behavior and hippocampus NO level: different responses of adolescent and adult C57BL/6J mice].

OBJECTIVE: To explore the difference between adolescent and adult C57BL/6J mice in response to rapid eye movement sleep (REMS) deprivation in terms of anxiety behavior and hippocampal NO level. METHODS: Both adolescent and adult C57BL/6J mice were divided into normal control (NC) group, wide platform (WP) group, and 24-hour REMS deprivation group, each group consisting of 15 mice. REMS deprivation models were established using a small platform in water tank, and the elevated plus maze test was used to examine anxiety behavior of the mice. After behavioral tests, the mice were sacrificed to examine hippocampal NO levels using enzyme-linked immunosorbent assay, and hippocampal nNOS protein expression was detected with Western blotting. RESULTS: The adolescent C57BL/6J mice showed no obvious differences in anxiety behaviors between the 3 groups, but NO level and nNOS expression in the hippocampus was significantly higher in REMSD group than in NC and WP groups (P<0.01). The adult mice in REMSD group, compared with those in the other two groups, exhibited significantly increased total number of arm entry (P<0.01), lowered number of open arm entry and reduced open arm time (P<0.01), increased number of close arm entry and prolonged close arm time (P<0.01 or 0.05); no obvious differences in NO level or nNOS expression in the hippocampus were found in the 3 groups of adult mice. CONCLUSION: REMS deprivation produces different effects on anxiety-related behaviors between adolescent and adult mice possibly in relation to their different responses in terms of NO levels and nNOS expression in the hippocampus.

Ultrasound-guided percutaneous microwave ablation for adenomyosis: efficacy of treatment and effect on ovarian function.

A total of 142 premenopausal women with symptomatic adenomyosis underwent ultrasound (US)-guided percutaneous microwave ablation (PMWA) at the Chinese PLA General Hospital. This study aimed to evaluate changes in serum pituitary, gonadal hormone and cancer antigen 125 (CA125) levels after US-guided PMWA. Therefore, estradiol (E2), follicle-stimulating hormone (FSH), prolactin (PRL) and CA125 levels were evaluated before ablation and at 3, 6, 9 and 12 months after ablation. No significant differences were observed in the E2 and FSH levels pre-ablation and during follow-up (E2: p=0.933, p=0.987, p=0.106, p=0.936; FSH: p=0.552, p=0.295, p=0.414, p=0.760). The mean absolute values of serum CA125 and PRL were significantly decreased at 3, 6, 9 and 12 months after ablation (CA125: p<0.001, p<0.001, p<0.001, p=0.003; PRL: p<0.001, p<0.001, p<0.001, p<0.001). A significant correlation between changes in CA125 levels and uterine volume was found (p<0.001). No evidence of a decline in ovarian function was observed after US-guided PMWA.

Ultrasound-guided percutaneous microwave ablation for submucosal uterine fibroids.

STUDY OBJECTIVE: To prospectively evaluate the efficiency and safety of ultrasound-guided percutaneous microwave ablation (PMWA) in treating symptomatic submucosal uterine myomas. DESIGN: Self-controlled study (Canadian Task Force classification II-1). SETTING: Single center. PATIENTS: Twenty-two premenopausal women with 22 symptomatic submucosal uterine myomas. INTERVENTION: All patients underwent ultrasound-guided PMWA. MEASUREMENTS AND MAIN RESULTS: PMWA was performed in 22 premenopausal women with 22 symptomatic submucosal uterine myomas. Mean (SD) patient age was 42 (4.60) years (95% confidence interval [CI], 39.96-44.04). Five symptomatic submucosal uterine myomas were identified as type 0, 7 as type 1, and 10 as type 2. Contrast-enhanced ultrasound and magnetic resonance imaging were performed before and after surgery. Myoma volume, hemoglobin concentration, and scores on the UFS-QOL (Uterine Fibroid Symptom and Quality of Life) questionnaire were recorded before and at 3 and 12 months after ablation. Complications were also recorded. In all patients, therapy was completed with a single ablation. The baseline diameter of the symptomatic submucosal uterine myomas was 4.90 (1.60) cm. Mean myoma volume reduction rate was 81.46% (16.33%) (95% CI, 73.06%-89.86%) at 3 months (p < .001) and reached 90.00% (9.79%) (95% CI, 85.07-95.13) at 12 months (p < .001). At 3 months after ablation, hemoglobin concentration increased from 88.64 (21.87) g/L (95% CI, 78.94-98.34) to 123.21 (15.77) g/L (95% CI, 115.10-131.32) (p < .001), and remained stable at 12 months, with a value of 125.92 (14.90) g/L (95% CI, 117.98-133.86). Scores on the UFS-QOL were comparable, with normal levels observed at 1 year. No major complications were observed. Nine patients were discharged with necrotic masses. CONCLUSION: PMWA seems to be effective and safe for treatment of submucosal myomas.

Chemical constituents from Solidago canadensis with hypolipidemic effects in HFD-fed hamsters.

Two new compounds, 8-dehydroxymethylvisanol (1) and 9-O-[3-O-acetyl-ß-d-glucopyranosyl]-4-hydroxy-cinnamic acid (4), together with two known lignans, visanol (2) and 9-aldehydevibsanol (3), were isolated from the 80% EtOH extract of Solidago canadensis. The structures of the two new compounds were elucidated on the basis of 1D, 2D NMR, and mass spectral analysis. All the lignans exhibited moderate hypolipidemic activity in high-fat diet-fed hamsters.

[Study on the anti-tumor effect of paclitaxel mixed micelle by using in vivo optical imaging technique].

In vivo tumor imaging technique method based on bioluminescence principle was established to evaluate the anti-tumor effect of paclitaxel mixed micelle (PMM). MDA-MB-231 tumor cells with luciferase reporter vectors were firstly implanted into nude mice, and subsequently the luciferase substrate was regularly injected during intraperitoneal administration of PMM. Then the tumor size, growth and the intensity of light signals were monitored with in vivo imaging technique. The method of luciferase tumor in vivo imaging could be real-time, reliable and exact in labeling and reflecting the growth of tumors, and the observed results were consistent with that by conventional method, so it would be a feasible approach to study anti-tumor effect of drugs. The anti-tumor effect of paclitaxel mixed micelle was observed by this method, and the results showed that this formulation could inhibit growth of tumor, and the anti-tumor rate of it was about 85%.

Investigation of structural requirements for inhibitory activity at the rat and housefly picrotoxinin binding sites in ionotropic GABA receptors using DISCOtech and CoMFA.

A number of widely diverse compounds that show inhibitory activities at the picrotoxinin binding sites in housefly and rat GABA receptors were investigated by using the distance comparison technique (DISCOtech) and comparative molecular field analysis (CoMFA) methods to explore the pharmacophore models and the three-dimensional quantitative structure-activity relationships (3D-QSAR) of the compounds. These compounds consist of three diverse types of noncompetitive GABA receptor antagonists, i.e., trioxabicyclooctanes and their derivatives, picrodendrins and related terpenoids, and fipronil and its analogs. For investigation of the structural requirements for inhibitory activity at the picrotoxinin binding site of GABA receptor, DISCOtech pharmacophore models containing one center of hydrophobic ring and two hydrogen bond acceptor atoms for both housefly-head and rat-brain GABA receptors were constructed, respectively. In particular, the interacting areas in housefly receptors appear to be wider than that in rat receptors, the differences between rat and housefly receptor models implicate the selectivity of noncompetitive GABA receptor antagonists. In addition, corresponding CoMFA models with good statistical indices (r(2)>0.9 and q(2)>0.5) were also obtained. These models can be used as guidance for the development of new compounds with high activities and selectivities.

[Changes of Smoothened expression during retinofugal pathway development in mouse embryos].

OBJECTIVE: To examine the change of Smoothened (Smo) expression in the retinofugal pathway and in the growth cones during the period of embryonic day 13 (E13) to E15. METHODS: Smo expression in the chiasm and growth cones was observed by fluorescent immunostaining and retinal explant culture. RESULTS: On E13 and E14, Smo was expressed moderately in the retina and optic disc, and in the corner of the retina, Smo expression was especially dense. On E13, Smo expression was detected in the optic nerves and ventral diencephalon, but only in the superficial region of the optic tract on E14. Smo was also detected in the stem and filopodia of the growth cones in the retinal explant culture during this period. CONCLUSION: Smo expression changes in different developmental phases, suggesting that Smo might play a role in signal optic axon growth during the development of the retinofugal pathway.

Changes of retinofugal pathway development in mouse embryos after Sonic hedgehog antibody perturbation.

OBJECTIVE: To understand the function of Sonic hedgehog in chiasm development in mouse embryos of embryonic day 13 (E13) to E15. METHODS: Brain slices of E13-E15 mouse embryos containing the optic pathway from the eyes to the optic tract were prepared and cultured in DMEM/F12 in the presence of 10% fetal bovine serum at 37 degrees in a rolling incubator for 5 h. The antibody to Shh was added into the culture medium of the slices in the treatment group, while no additional chemical or only normal mouse IgG was added in the control groups. After culture, the brain slices were fixed and a DiI granule was inserted into the optic disc in one eye. Seven days later, the tissue overlying the chiasm was removed to expose the DiI-labeled chiasm for observation under confocal microscope, and the images were analyzed by METAMORPH software. RESULTS: Shh antibody treatment produced a reduction of crossing of the earliest retinal axons at the midline of E13 chiasm, and the uncrossed axons were also influenced by Shh antibody at E15. CONCLUSION: Shh executes a transient but important function in axon decussation in the early stage of mouse optic chiasm development and signals axon turning in the later stage.

In-vitro cytotoxicity, in-vivo biodistribution and anti-tumour effect of PEGylated liposomal topotecan.

In attempt to increase the accumulation of topotecan in tumours and improve its anti-cancer activity, PEGylated liposome (H-PEG) containing topotecan was prepared. The in-vitro cytotoxicity, in-vivo biodistribution pattern and anti-tumour effect of H-PEG were studied systemically. Compared with free topotecan or conventional liposome (H-Lip), H-PEG improved the cytotoxic effect of topotecan against human ovarian carcinoma A2780 and human colon carcinoma HCT-8 cells. The IC50 value (concentration leading to 50% cell-killing) of H-PEG decreased 5 fold (P<0.01) and 9 fold (P<0.01) against A2780 and HCT-8 cells compared with H-Lip, respectively. The results of biodistribution studies in sarcoma S(180) tumour-bearing mice showed that liposomal encapsulation increased the concentration of total topotecan and the ratio of lactone form in plasma. H-PEG resulted in a 70-fold and 3.7-fold increase in AUC(0-->24 h) compared with free topotecan and H-Lip, respectively. Moreover, H-PEG increased the accumulation of topotecan in tumours and the relative tumour uptake ratio compared with free topotecan was 5.2, and higher than that of H-Lip. The anti-cancer effect studies in murine heptocarcinoma H(22) tumour-bearing mice showed that H-PEG improved the therapeutic efficiency of topotecan and decreased the toxicity of topotecan to a certain extent compared with H-Lip. These results indicated that PEG-modified liposome might be an efficient carrier of topotecan.

[Preparation of cardiomyocyte-targeting liposomes and their targeting ability in vitro].

AIM: To prepare the cardiomyocyte-targeting liposomes and investigate their cardiomyocyte targetability in vitro. METHODS: Liposomes modified with compound PAC were prepared (PAC-L); The uptake of PAC-L by cardiomyocytes was studied by incubating fluorescence labeled liposomes with cardiomyocytes in vitro and measuring the association of liposomes by a fluorescence spectrophotometer. RESULTS: A high affinity of PAC-L to the cardiomyocytes was observed, the amount of cell uptake of PAC-L by cardiomyocytes was higher than that by nonmyocyte (P < 0.001); The amount of cardiomyocyte uptake of PAC-L on the normoxia condition 2 h was 2.9-fold higher than that of plain-L, and the increase was 5.2-fold when hypoxia occured; The form of liposome uptake changed, the amount of cardiomyocyte uptake of Plain-L by internalization was only 11%, while that of PAC-L was 56%. CONCLUSION: It is indicated that PAC-L was a potential drug carrier for targeting to ischemic myocardium.

In vitro and in vivo studies of different liposomes containing topotecan.

Liposome as a carrier of topotecan (TPT), a promising anticancer drug, has been reported in attempt to improve the stability and antitumor activity of TPT. However, the biodistribution pattern of TPT liposome in vivo and PEG-modified liposome containing TPT have not been studied systemically. In this paper, the in vitro stability and in vivo biodistribution behavior of several liposomes containing TPT with different lipid compositions and PEG-modification were studied. Compared with the 'fluid' liposome (S-Lip) composed of soybean phosphatidylcholine (SPC), the 'solid' liposome (H-Lip) composed of hydrogenated soybean phosphatidylcholine HSPC decreased the leaking efficiency of TPT from liposome and enhanced the stability of liposome in fetal bovine serum (FBS) or human blood plasma (HBP). The results of biodistribution studies in S180 tumor-bearing mice showed that liposomal encapsulation increased the concentrations of total TPT and the ratio of lactone form in plasma. Compared with free TPT, S-Lip and H-Lip resulted in 5- and 19-fold increase in the area under the curve (AUC(0-->infinity)), respectively. PEG-modified H-Lip (H-PEG) showed 3.7-fold increase in AUC(0-->infinity) compared with H-Lip, but there was no significant increase in t(1/2) and AUC(0-->infinity) for PEG-modified S-Lip (S-PEG) compared with S-Lip. Moreover, the liposomal encapsulation changed the biodistribution behavior, and H-Lip and H-PEG dramatically increased the accumulation of TPT in tumor, and the relative tumor uptake ratios were 3.4 and 4.3 compared with free drug, respectively. There was also a marked increase in the distribution of TPT in lung when the drug was encapsulated into H-Lip and H-PEG. Moreover, H-PEG decreased the accumulation of TPT in bone marrow compared with unmodified H-Lip. All these results indicated that the membrane fluidity of liposome has an important effect on in vitro stability and in vivo biodistribution pattern of liposomes containing TPT, and PEG-modified 'solid' liposome may be an efficient carrier of TPT.

Regionally specific expression of L1 and sialylated NCAM in the retinofugal pathway of mouse embryos.

We have examined expression of L1 and the polysialic acid-associated form of the neural cell adhesion molecule (PSA-NCAM) in mouse embryos during the major period of axon growth in the retinofugal pathway to determine whether they are expressed in patterns that relate to the changes in axon organization in the pathway. Immunostaining for L1 and PSA-NCAM was found on all axons in the retina and the optic stalk. In the chiasm, while L1 immunoreactivity remained high on the axons, PSA-NCAM staining was obviously reduced. At the threshold of the optic tract, L1 immunoreactivity was maintained only in a subpopulation of axons, whereas PSA-NCAM staining was dramatically elevated in axons at the caudal part of the tract. Further investigations of the tract showed that both L1 and PSA-NCAM were preferentially expressed on the dorsal but not ventral optic axons, indicating a regionally specific change of both adhesion molecules on the axons at the chiasm-tract junction. Moreover, intense PSA-NCAM expression was also observed in the tract of postoptic commissure (TPOC), which lies immediately caudal to the optic tract. Immunohistochemical and retrograde tracing studies showed that these PSA-NCAM-positive axons arose from a population of cells rostral to the CD44-positive chiasmatic neurons. These findings indicate that, in addition to the chiasmatic neurons, these PSA-NCAM-positive diencephalic cells also contribute axons to the TPOC. These early generated commissural axons together with the regionally specific pattern of cell adhesion molecule expression on the optic axons may control formation of the partial retinotopic axon order in the optic tract through homophilic or heterophilic interactions that involve PSA-NCAM.