Use of a non-covalent cell-penetrating peptide strategy to enhance the nasal delivery of interferon beta and its PEGylated form.

The conjugation of therapeutic proteins to polyethylene glycol (PEG) is known as PEGylation. It improves their retention in the body and reduces the frequency of injections. Development of noninvasive delivery systems for biopharmaceuticals can improve the patients' quality of life. The present study aimed to evaluate the cell-penetrating peptides (CPPs), which act as bioenhancers, for the nasal delivery of protein drug interferon beta (IFN-ß) and its PEGylated form (PEG-IFN-ß). The ability of CPPs to enhance the nasal mucosal absorption of unmodified IFN-ß was assessed in rats. It was shown that only d-amino acid forms of amphipathic CPPs, penetratin and PenetraMax significantly enhanced the nasal absorption of IFN-ß. Especially, D-penetratin (up to 2mM) enhanced the absorption of INF-ß in a dose-dependent manner. The maximum absolute bioavailability reached 8.26% following in situ nasal coadministration of IFN-ß with d-penetratin (2mM). Furthermore, it was found that the coadministration of d-penetratin also facilitated the nasal absorption of PEG-IFN-ß, which remained in the circulation for more than 6h. Moreover, the toxicity assessments showed no damage to the epithelial membranes after nasal administration of CPPs including penetratin and PenetraMax. Altogether, this study provides the first evidence that the noncovalent coadministration of PEGylated proteins with CPPs could be a potent strategy for the noninvasive and sustained nasal delivery of therapeutic proteins.

A Biomimicking Tumor Tissue Model Using Hepatocellular Carcinoma Cell Sheet in a Collagen Sandwich System.

Cytotoxic efficacy of anticancer drugs has been widely studied with monolayer-cultured cancer cells. However, the drug efficacy under two-dimensional (2D) culture conditions usually differs from that of three-dimensional (3D) culture conditions. In the present study, an in vitro tumor tissue model was constructed by sandwiching a cancer cell monolayer (cancer cell sheet) between two collagen layers as a biomimicking tumor tissue model, and the in vitro cytotoxic efficacy of doxorubicin was investigated. In the biomimicking tumor tissue model, hypoxic areas were observed, and the secretion of vascular endothelial growth factor increased time-dependently. Additionally, cell growth inside the model was significantly slower than that of the 2D culture system. The in vitro cytotoxicity of doxorubicin with the 3D system decreased compared to the 2D system, suggesting that the surrounding collagen layer acted as a barrier much like cancer stroma does. Consequently, this study successfully demonstrated that the cancer cell sheet in collagen sandwich configuration provides a useful in vitro tumor tissue model.

Facile cell sheet manipulation and transplantation by using in situ gelation method.

Cell sheets harvested from temperature-responsive cell culture dishes (TRDs) has attracted considerable attention as effective tools for reconstructing the lost functions of tissues and organs in the regenerative medicine field. However, because of their thinness, handling problems sometimes arise when transferring cell sheets from a TRD to a target surface. In this study, we developed a facile cell transfer method referred to as in situ gelation by using both gelatin hydrogel and a support membrane. Gelation and low-temperature processes were simultaneously performed on TRD. Confluent cultured cells were efficiently harvested from TRD in less than 5 min by decreasing the incubation temperature to 20°C. Harvested cells were found to maintain their cell viability, extracellular matrix, and original shape, thus allowing transfer of the cells to another surface with a short incubation time at 37°C. This method is applicable for various cell types regardless of the formation of tight cell-cell junctions. In addition, because of the high flexibility of the gelatin-coated membrane, cells were efficiently transferred to the surface of a mouse subcutis and liver. When compared with conventional cell sheet manipulation methods, the interaction between the cell surface and membrane was reinforced by the uniformly formed gelatin gel layer without using a special device. Therefore, the in situ gelation method is a promising technique for cell sheet-based tissue engineering and regenerative medicine.

A combination of liposomal sunitinib plus liposomal irinotecan and liposome co-loaded with two drugs enhanced antitumor activity in PC12-bearing mouse.

Pheochromocytomas are highly angiogenic neuroendocrine tumors. The side effects of treatment with cytotoxic agents frequently outweigh the benefits. Neuroendocrine tumors are highly angiogenic, dependent on vascular endothelial growth factor and receptor (VEGFR) activation. Sunitinib has antitumor and antiangiogenic activities that target VEGFRs. We investigated the antitumor activity of liposomal sunitinib and irinotecan alone and in combination. Liposomal sunitinib and irinotecan, and liposomes co-loaded with both drugs were prepared, and antitumor activity and biodistribution were examined in nude mice bearing PC12 tumors. Liposomal sunitinib increased in life span (ILS, 14.3%) compared with free sunitinib (-17.1% ILS) with moderate tumor growth suppression, whereas liposomal irinotecan suppressed tumor growth significantly without a survival benefit compared with free irinotecan (-21.7 and -13.3% ILSs, respectively). The combination of liposomal sunitinib plus liposomal irinotecan, and liposomes co-loaded with both drugs, induced significant inhibition of tumor growth and increased life-span more than the combination of free drugs. Accumulation of irinotecan in tumors by the combination of the two liposomal drugs and liposomes co-loaded with both drugs was significantly increased compared with the combination of free drugs. This study provides novel formulations of sunitinib and irinotecan in combination for the treatment of pheochromocytoma.

Preparation and in vivo evaluation of liposomal everolimus for lung carcinoma and thyroid carcinoma.

Everolimus has demonstrated antitumor efficacy for various cancers as a result of its inhibition of the mammalian target of rapamycin (mTOR) signaling cascade, which activates cell growth and cell proliferation. However, the low water solubility and low bioavailability of everolimus have prevented its clinical development as an anticancer drug. Therefore, to address the unsuitable characteristic of everolimus, we attempted to prepare liposomal everolimus as a viable drug delivery system, and then evaluated the anticancer efficacy of this system against a medullary thyroid carcinoma cell line (TT cells), a breast cancer cell line (MCF-7 cells) and a small lung carcinoma cell line (NCI-H446 cells). The particle size and entrapment efficacy of liposomal everolimus was ca. 80 nm and more than 90%, respectively. Liposomal everolimus showed higher cytotoxicity against NCI-H446 cells compared with TT cells. Against NCI-H446 tumors, significant suppression of the tumor volume was observed in liposomal everolimus-treated mice by intravenous injection, compared with free everolimus-treated mice by intraperitoneal injection, at a dose of 5 mg/kg without body weight loss. This study showed that liposomal everolimus could be a powerful formulation with anticancer efficacy for some cancers.

Dual functional octreotide-modified liposomal irinotecan leads to high therapeutic efficacy for medullary thyroid carcinoma xenografts.

Medullary thyroid carcinoma is a rare endocrine tumor, which shows overexpression of somatostatin receptor subtype 2. There is no systemic therapy for medullary thyroid carcinoma. Previously we reported that octreotide-PEG liposomes loaded with irinotecan, which target somatostatin receptor subtype 2, showed high therapeutic efficacy for medullary thyroid carcinoma xenografts compared with free irinotecan or non-targeted non-PEGylated liposomal irinotecan. In this study, we evaluated octreotide-PEG liposomes loaded with irinotecan in terms of the biodistribution of irinotecan and its active metabolite, and its therapeutic efficacy, compared with PEGylated liposomes. Furthermore, to elucidate the effect of octreotide ligand after cellular association, we assessed the cytotoxicity in tumor cells and the inhibition of protein phosphorylation in the tumor cells and xenografts using empty octreotide-PEG liposomes, which were loaded with no drug. In a therapeutic study, octreotide-PEG liposomes loaded with irinotecan significantly improved median survival compared with PEGylated liposomes. In tumor tissue at 6 h after injection, octreotide-PEG liposome-treated mice showed significantly higher concentrations of irinotecan and 7-ethyl-10-hydrocamptothecin compared with PEGylated liposome-treated mice, indicating that octreotide-PEG liposomes accumulated rapidly and to a high level in the tumor. Furthermore, empty octreotide-PEG liposome inhibited the phosphorylation of p70S6K in vitro and in vivo. These findings indicated that octreotide-PEG liposomal irinotecan has dual functions with targeted tumor delivery and assistance of cellular cytotoxicity, which led to higher therapeutic efficacy than PEGylated liposomes for medullary thyroid carcinoma xenografts.

Octreotide-targeted liposomes loaded with CPT-11 enhanced cytotoxicity for the treatment of medullary thyroid carcinoma.

Medullary thyroid carcinoma (MTC) is a rare endocrine tumor that frequently metastasizes, but treatment with irinotecan (CPT-11) is limited because of side effects. MTC is known to overexpress the somatostatin receptor subtype 2 (SSTR2). Octreotide (Oct) is a somatostatin analogue that has a high binding affinity for SSTR and can be used as a tumor-targeting ligand. We prepared Oct-targeted liposomes loaded with CPT-11 using Oct-poly (ethylene glycol) (PEG)-lipid and evaluated Oct-mediated association and cytotoxicity of the liposomes with an MTC cell line TT. The association of higher concentrations of modified Oct-targeted liposomes with TT cells was significantly higher than PEGylated liposomes and was significantly inhibited by empty Oct-targeted liposomes but not by free Oct. With exposure for 96 h, the cytotoxicity of Oct-targeted liposomal CPT-11 (IC50: 1.05 ± 0.47 µM) was higher than free CPT-11 (IC50: 3.76 ± 0.61 µM) or PEGylated liposomal CPT-11 (IC50: 3.05 ± 0.28 µM). In addition, empty Oct-targeted liposomes showed significantly higher cytotoxicity than empty nontargeted liposomes at a concentration where free Oct did not show cytotoxicity, suggesting that Oct as a ligand showed cytotoxicity. Moreover, Oct-targeted liposomal CPT-11 led to significantly higher antitumor activity and prolonged the survival time compared with nontargeted liposomal and free CPT-11 at a one-third dose and lower administration times with free CPT-11. These findings indicated that Oct-targeted liposomes loaded with CPT-11 may offer considerable potential for MTC chemotherapy because cytotoxicity of both CPT-11 and Oct was enhanced by effective cellular uptake via SSTR2.

Primary cutaneous T-cell lymphoma of unspecified type with cytotoxic phenotype: clinicopathological analysis of 27 patients.

The objective of our study was to investigate the clinicopathological features of the currently ill-defined subtype of primary cutaneous T-cell lymphoma of unspecified type (CTCLU) with a cytotoxic phenotype and no Epstein-Barr virus (EBV) association. A series of 27 patients with CTCLU (median age 49 years; range 25-87 years; 18 men) was reviewed. Performance status scores above 1 (7%), clinical stages above 2 (15%), B symptoms (26%), extracutaneous involvement (30%), and a fatal course within 1 year of diagnosis (19%) were observed infrequently. The International Prognostic Index was high or high to intermediate in 11%, and the Prognostic Index for Peripheral T-cell Lymphoma unspecified was above group 2 in 22%. Notably, the rates of spontaneous regression and T-cell receptor gene rearrangements by polymerase chain reaction analysis were seen in 26 and 17% of our cases, respectively. Histologically, 22 patients had subcutaneous involvement of whom eight showed a lethal clinical course, and five patients without subcutaneous involvement were all survivors. Immunophenotypical and morphological features allowed us to subclassify our cases according to the following four categories: (1) epidermotropic CD8+ T-cell lymphoma (n=5); (2) cutaneous gamma/delta T-cell lymphoma (n=8); (3) cutaneous alpha/beta pleomorphic T-cell lymphoma (n=8); and (4) cutaneous medium/large pleomorphic T-cell lymphoma, not otherwise specified (n=6). All four of these groups of lymphomas exhibited a relatively favorable clinical course compared to previous reports. However, epidermotropic CD8+ T-cell lymphoma appeared to be unique with a higher ratio (80%) of spontaneous regression, a lower ratio (40%) of subcutaneous involvement, and a more favorable clinical course than the other three subcategories.

Effects of 8-2 fluorotelomer alcohol on oleic acid formation in the liver of rats.

Effects of 8-2 fluorotelomer alcohol on fatty acid composition of lipid in the liver of rats were investigated. Feeding of male rats with a diet that contained 8-2 fluorotelomer alcohol at concentrations of 0.2, 0.4 and 0.8% (w/w) for 14 d caused a significant increase in proportion and content of oleic acid (18 : 1 (n-9)) in the liver. The treatment of rats with 8-2 fluorotelomer alcohol increased activities of palmitoyl-CoA chain elongase (PCE) and stearoyl-CoA desaturase (SCD) and mRNA expressions for rat fatty acid elongase 2 (rELO2) and stearoyl-CoA desaturase 1 (SCD1), but neither rat fatty acid elongase 1 (rELO1) or stearoyl-CoA desaturase 2 (SCD2), in the liver in dose-dependent manners. Multiple regression analyses, which were performed to estimate relative contribution of PCE and SCD for determination of the proportion or the content of 18 : 1 (n-9), revealed that the three parameters were significantly correlated and that standardized partial regression coefficient of PCE was higher than that of SCD. These results suggest that 8-2 fluorotelomer alcohol caused considerable changes in the composition and the content of fatty acid, especially 18 : 1 (n-9), in the liver by inducing PCE and SCD, and that PCE plays a crucial role in the increased proportion of 18 : 1 (n-9) in the liver of the rats given fluorotelomer alcohol.

Induction of hepatic peroxisome proliferation by 8-2 telomer alcohol feeding in mice: formation of perfluorooctanoic acid in the liver.

The effects of dietary administration of 1H, 1H, 2H, 2H-perfluorodecanol (8-2 telomer alcohol), on peroxisome proliferation in the liver of mice were studied. Male ddY mice were fed on a diet containing 8-2 telomer alcohol at concentrations of 0, 0.025, 0.05, 0.1, and 0.2% (w/w) for 7, 14, 21, and 28 days. These treatments with 8-2 telomer alcohol caused liver enlargement in a dose- and duration-dependent manner. Peroxisome proliferation in the liver of mice was confirmed by electron microscopic examination. Peroxisomal acyl-CoA oxidase was induced by these treatments with 8-2 telomer alcohol in a dose- and time-dependent manner. The concentration of perfluorooctanoic acid (PFOA) and related compounds were determined in the liver and plasma, since PFOA had been shown to be a possible metabolite of 8-2 telomer alcohol and to cause significant peroxisome proliferation in rodents. Five metabolites, namely, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), 2H, 2H-perfluorodecanoic acid (8-2 telomer acid), and two unidentified metabolites, were present in the liver and serum. PFOA was confirmed to be accumulated in the liver of mice following the administration of 8-2 telomer alcohol in a dose- and duration-dependent manner. A linear relationship was observed between the concentration of PFOA and the activity of peroxisomal acyl-CoA oxidase in the liver of mice. These results strongly suggest that PFOA, but not 8-2 telomer alcohol itself, caused peroxisome proliferation in the liver. The present study provided evidence that 8-2 telomer alcohol is converted into PFOA in vivo and that the PFOA formed produces biological effects in the liver of mice.