iRGD-modified sterically stabilized liposomes loaded doxorubicin (iRGD-SSL-DOX) were prepared and their cellular toxicity and anti-tumor efficacy were evaluated, comparing to doxorubixin loaded sterically stabilized liposomes (SSL-DOX) and RGD modified doxorubixin loaded sterically stabilized liposomes (RGD-SSL-DOX). The iRGD peptide, with both tumor targeting and cell penetrating functions, was conjugated to DSPE-PEG-NHS and DSPE-PEG-iRGD was obtained. DSPE-PEG-RGD was gained in the same way. iRGD-SSL-DOX, RGD-SSL-DOX and SSL-DOX were prepared by ammonium sulfate gradient method. The size and zeta potential of the liposomes were characterized by dynamic laser light scattering. The cellular toxicity study was done on B16 melanoma cell line and the anti-tumor efficacy study was carried on B16 cell line bearing C57BL/6 mice. The results showed that the particle sizes of liposomes were all around 90-100 nm. DOX entrapment efficiency was above 95%. The formulations were with good preparation reproducibility. iRGD-SSL-DOX showed no significant difference in B16 cellular toxicity with SSL-DOX and RGD-SSL-DOX, but the anti-tumor efficacy on B16 melanoma bearing C57BL/6 mice was significantly better than that of SSL-DOX, similar as that of RGD-SSL-DOX. Therefore, iRGD modified liposomes loaded DOX would be a promising drug delivery system for tumor therapy.
Animals ; Antibiotics, Antineoplastic ; administration & dosage ; pharmacology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Doxorubicin ; administration & dosage ; pharmacology ; Drug Carriers ; Drug Delivery Systems ; Liposomes ; Male ; Melanoma, Experimental ; pathology ; Mice ; Mice, Inbred C57BL ; Molecular Weight ; Neoplasm Transplantation ; Oligopeptides ; chemistry ; pharmacology ; Particle Size ; Phosphatidylethanolamines ; chemistry ; Polyethylene Glycols ; chemistry ; Tumor Burden ; drug effects

Doxorubicin loaded micelles were prepared by film-hydration method using stearyl sulfadiazine (SA-SD) which is pH sensitive, methoxy (polyethylene glycol)-2000-1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine (mPEG-DOPE) and transactivator of transcription (TAT) peptide conjugated PEG-DOPE. Mean diameter of the pH-sensitive micelles was about 20 nm with a (99.1 +/- 2.1) % drug entrapment efficiency at pH 7.4. Flow cytometry studies revealed that the simple TAT micelles was taken up rapidly at the same level at pH 6.8 and pH 7.4. However, the pH-sensitive micelles entered the tumor cell less at pH 7.4 and significantly increase at pH 6.8. After 1 h incubation at pH 6.8, the amount of the pH-sensitive micelles taken up by cancer cell 4T1 was almost similar to simple TAT micelles. The confocal microscopy indicated that the pH-sensitive micelles entered the 4T1 cells at pH 6.8 more than at pH 7.4. It was indicated that the pH-sensitive micelles could shield TAT peptide at normal pH 7.4 and deshield it at pH 6.8. Hence, TAT peptides lead the drug-loaded micelles into the tumor cells and killed them selectively. The pH-sensitive micelle may provide a novel strategy for design of cancer targeting drug delivery system.
Animals ; Antibiotics, Antineoplastic ; administration & dosage ; chemistry ; Cell Line, Tumor ; Cell-Penetrating Peptides ; chemistry ; Doxorubicin ; administration & dosage ; chemistry ; Drug Carriers ; Drug Compounding ; Drug Delivery Systems ; Female ; Gene Products, tat ; chemistry ; Hydrogen-Ion Concentration ; Mammary Neoplasms, Experimental ; pathology ; Mice ; Micelles ; Phosphatidylethanolamines ; chemistry ; Polyethylene Glycols ; chemistry ; Sulfadiazine ; chemistry

PURPOSE: Bisphophonates are drugs used to suppress osteoclastic activity and to treat osteoporosis, Paget's disease of bone and bone metastasis. The purpose of this report is to review the literatures on bisphopsphonates use that could affect bone healing and cause osteonecrosis of the jaws. MATERIALS AND METHODS: Medline research was carried out to find relevant articles on bisphophonates and osteonecrosis of the jaw. RESULTS: Oral administration of bisphopsphonates is reported to decrease the risk of adverse bone outcomes. On the contrary, IV bisphopsphonates is known to significantly increase the risk. Prevention of the osteonecrosis of the jaw is primary concern before usage. If the adverse bone reaction takes place, proper management and treatments are required to alleviate pain of patients and prevent further progression of necrosis. CONCLUSION: Case reports of bisphosphonates induced osteonecrosis of the jaw are increasing. Dentists and physicians should be aware of the higher frequency of osteonecrosis of the jaw in patients receiving IV bisphopsphonates and be prepared to prevent and cope with adverse bone reaction.
Administration, Oral ; Dentists ; Diphosphonates ; Humans ; Hypogonadism ; Jaw ; Mitochondrial Diseases ; Necrosis ; Neoplasm Metastasis ; Ophthalmoplegia ; Osteitis Deformans ; Osteoclasts ; Osteonecrosis ; Osteoporosis ; Phosphatidylethanolamines ; Risk Assessment

Use of adenoviruses as vehicle for gene therapy requires that target cells express appropriate receptors such as coxsakievirus and adenovirus receptor (CAR). We show here that CAR-deficiency in cancer cells, that limits adenoviral gene delivery, can be overcome by using adenovirus complexed with the liposome, Ad-PEGPE [1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly-ethylene glycol)-2000]. We first confirmed that CT-26 mouse colon cancer cells are deficient in CAR by RT-PCR, and then showed that CT-26 cells infected with Ad-GFP/PEGPE exhibited highly enhanced expression of green fluorescent protein (GFP), compared with those infected with Ad-GFP. GFP expression depends on the dose of liposome and adenovirus. Luciferase expression in livers treated with Ad-luc/PEGPE was about 1,000-fold less than those infected with Ad-luc. In a liver metastasis mouse tumor model developed by intrasplenic injection of CT-26 cells, luciferase expression following i.v. injection of Ad-luc/PEGPE was significantly higher in tumors than in adjacent non-neoplastic liver. Following systemic administration of Ad-GFP/PEGPE, GFP expression increased in tumors more than in adjacent liver while the reverse was true following administration of Ad-GFP. In the latter case, GFP expression was higher in liver than in tumors. This study demonstrates that systemic delivery of PEGPE-adenovirus complex is an effective tool of adenoviral delivery as it overcomes limitation due to CAR deficiency of target cells while reducing hepatic uptake and enhancing adenoviral gene expression in tumors.
*Adenoviridae/genetics/metabolism ; Animals ; Colonic Neoplasms/*genetics/metabolism/pathology/*therapy ; Dose-Response Relationship, Drug ; Gene Therapy ; *Gene Transfer Techniques ; Genetic Vectors ; Green Fluorescent Proteins/genetics ; Liposomes/administration & dosage/chemistry/pharmacokinetics/*therapeutic use ; Liver/drug effects/metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Transgenic ; NIH 3T3 Cells ; Phosphatidylethanolamines/administration & dosage ; Polyethylene Glycols/administration & dosage ; Receptors, Cytoplasmic and Nuclear/deficiency/genetics ; Receptors, Virus/deficiency/*genetics ; Transcription Factors/deficiency/genetics ; Tumor Cells, Cultured

A cationic liposome was prepared with a ligand directed at folate receptor in cancer cells to improve selectivity and facilitate its access to the cancer cells. Folate-polyethyleneglycol-distearoylphosphatidylethanolamine (F-PEG-DSPE) was synthesized by reacting folic acid (F), polyoxyethylene-bis-amine (NH2-PEG-NH2), succinic anhydride (SUC) with distearoylphosphatidylethanolamine (DSPE). Folate receptor-targeted liposomes composed of DPPC/DC-Chol/F-PEG-DSPE (10:10:0.75, molar ratio) were prepared by film dispersion method. A negative charged dextran fluorescein anionic (DFA) was used as a model to explore the in vitro properties and cell uptake efficiencies of liposomal DFA on KB and HpeG2 cells. The formulations were investigated by orthogonal experiment using encapsulation efficiency as the optimized indexes. The size, 4 potential, entrapment efficiency and DFA release in vitro were investigated. The results showed that DFA loaded folate receptor-targeted liposomes had high encapsulation efficiency and the mean size approximately 144 nm. The cationic liposomes had some toxicity to HepG2 cells, and at low concentration (0.0125-0.1 micromol x L(-1)) , the toxicity was linear with the concentration of DC-chol. The folate receptor-targeted liposomes showed great effects on increasing liposome cellular uptake of DFA. In summary, the method of film dispersion method is suitable for producing DFA loaded lipsomes with high entrapment efficiency, small size and slow release. The folate receptor-targeted liposomes can efficiently deliver DFA into cells in vitro. This may represent a promising option for researches on cancer gene therapy.
Carrier Proteins ; metabolism ; Dextrans ; chemistry ; Drug Carriers ; Drug Delivery Systems ; Fluoresceins ; chemistry ; Folate Receptors, GPI-Anchored ; Folic Acid ; chemistry ; Genetic Therapy ; Hep G2 Cells ; Humans ; KB Cells ; Liposomes ; administration & dosage ; chemical synthesis ; metabolism ; Particle Size ; Phosphatidylethanolamines ; chemistry ; Polyethylene Glycols ; chemistry ; Receptors, Cell Surface ; metabolism ; Transfection

AIMTo prepare the PEGylated liposomes modified with cell penetrating peptides, which protect siRNA from nuclease degradation and deliver efficiently siRNA into cells to facilitate silencing of target gene.

METHODSThe purity of R8-PEG-PE and pNP-PEG-PE was detected by HPLC; the quantity of R8, PEG-DPPE modified R8, and R8 attached to the out membrane surface of the liposomal siRNA by transfer from R8-PEG-DPPE micelles to the liposomes was tested by fluorescence; Size and size distribution of siRNA loaded liposomes with and without attached R8 were determined by Zetasizer 5000; A comparison of mediated siRNA transfection efficiency between R8-liposomes and lipofectamine 2000 was examined by individual inside cell fluorescence intensity; The growth inhibition of small cell lung carcinoma NCI-H446 cells treated with R8-liposomal hdm2-siRNA or lipofectamine 2000-hdm2-siRNA complex was tested by MTT assay.

RESULTSThe retention times of PEG-DPPE and R8-PEG-DPPE were 9.0 min and 7.8 min, respectively. Fluorescence scanning indicated that lipids composed of liposomes and siRNAs didn't interfere to the determination of R8 when it was attached to the liposomal siRNA. The cells treated with R8-liposomal hdm2-siRNA significantly enhanced the cellular uptake of hdm2-siRNA and facilitated the functions of hdm2-siRNA through silencing of target gene which, in turn, inhibited tumor cell growth, compared with lipofectamine 2000.

CONCLUSIONThe R8 attached liposomes are shown to be powerful carriers for delivery siRNAs into cell to silence targeted gene.

Carcinoma, Small Cell ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Gene Silencing ; Gene Targeting ; Humans ; Liposomes ; Lung Neoplasms ; metabolism ; pathology ; Oligopeptides ; administration & dosage ; pharmacology ; Phosphatidylethanolamines ; Polyethylene Glycols ; Proto-Oncogene Proteins c-mdm2 ; genetics ; metabolism ; RNA, Small Interfering ; administration & dosage ; metabolism ; pharmacology ; Transduction, Genetic

AIMTo investigate the possibility of using stealth liposomes modified with arginine-glycine-aspartic acid (RGD) mimetic as the targeted carriers to achieve increased accumulation in tumor and enhanced intracellular delivery for the encapsulated anticancer drugs.

METHODSRGD mimetic (RGDm) as a ligand for integrins was synthesized and covalently conjugated to the active PEGylated phospholipids (DSPE-PEG-BTC) to form RGDm conjugate (DSPE-PEG-RGDm). Then RGDm-modified SL (RGDm-SL) containing DOX (RGDm-SL-DOX) and SL containing DOX (SL-DOX) were prepared by film dispersion followed by ammonium sulfate gradient method. The pH-sensitive probe, BCECF-AM, was used to study the binding of melanoma cells to DSPE-PEG-RGDm. Flow cytometry and confocal microscopy were performed to evaluate the cellular association or DOX uptake for RGDm-SL-DOX or SL-DOX in vitro.

RESULTSThe melanoma cells A375 and B16 showed enhanced binding to the immobilized DSPE-PEG-RGDm. The cells treated with RGDm-SL-DOX showed remarkable increase in cellular association or DOX uptake compared with SL-DOX.

CONCLUSIONThe RGDm-modified SL could be as the targeted carriers to facilitate the delivery of the encapsulated anti-cancer drugs into tumor cells by receptor-mediated way.

Animals ; Antibiotics, Antineoplastic ; administration & dosage ; metabolism ; Cell Adhesion ; Cell Line, Tumor ; Cell Nucleus ; metabolism ; Doxorubicin ; administration & dosage ; metabolism ; Drug Carriers ; Drug Delivery Systems ; Humans ; Liposomes ; Melanoma, Experimental ; metabolism ; pathology ; Oligopeptides ; Phosphatidylethanolamines ; Polyethylene Glycols

AIMTo investigate the biodistribution and the hepatocytes targeting of cationic liposome containing 3beta[N-( N',N'-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol) and surface-modified liposomes with sterylglucoside (SG) and polyethylene glycol-distearoylphosphatidylethanolamine (PEG-DSPE).

METHODSCationic liposomes (CL) composed of DC-Chol and dipalmitoylphosphatidylcholine (DPPC), SG/PEG modified cationic liposome (SG/PEG-CL), both contained trace 3H-cholesterol (3H-Chol) as radiolabel, were prepared. The liposomes encapsulating 125I-labled antisense oligodeoxynucleotide (125I-asODN) (SG/PEG-CL-asODN) were also prepared. The biodistribution of CL, SG/PEG-CL, SG/PEG-C2-asODN as well as 125I-asODN solution, were studied. The radioactivities in hepatocytes and non-hepatocytes after administration of CL and SG/PEG-CL were determined by infuseing method.

RESULTSCL and SG/PEG CL significantly aggregated in liver. The distribution of SG/PEG CL was significantly higher in hepatocytes (P < 0.01) and lower in non-hepatocytes (P < 0.01) than that of CL. The concentrations of SG/PEG-CL-asODN in liver and spleen were significantly higher than that of asODN solution (P < 0.01).

CONCLUSIONCationic liposome modified with SG/PEG changed the distribution of asODN. Cationic liposome can target hepatocytes more effective after being modified with SG.

1,2-Dipalmitoylphosphatidylcholine ; administration & dosage ; pharmacokinetics ; Animals ; Area Under Curve ; Cholestenes ; administration & dosage ; pharmacokinetics ; Cholesterol ; administration & dosage ; analogs & derivatives ; pharmacokinetics ; Drug Carriers ; Drug Delivery Systems ; Hepatocytes ; metabolism ; Liposomes ; administration & dosage ; pharmacokinetics ; Male ; Mice ; Oligodeoxyribonucleotides, Antisense ; administration & dosage ; pharmacokinetics ; Phosphatidylethanolamines ; administration & dosage ; pharmacokinetics ; Polyethylene Glycols ; administration & dosage ; pharmacokinetics ; Tissue Distribution

AIMTo investigate the enhancing effect on insulin absorption through GI tract in mice by using tomato lectin (TL) modified liposomes as the carrier.

METHODSTL-phosphatidylethanolamine (PE) conjugate (TL-PE) was synthesized by using carbodiimide cross-linking method, then the compound was incorporated into the conventional liposomes of insulin. The agglutination test was performed to examine TL biological activities after synthesis and incorporation. When TL modified liposomes were administrated orally to the normal mice or diabetic mice at insulin dose of 350 u x kg(-1), the hypoglycemic effect was determinated according to the blood glucose level.

RESULTSThe blood glucose levels of the normal mice were reduced by modified liposomes. The glucose levels were (85 +/- 5)% at 4 h, (54 +/- 11)% at 8 h, (57 +/- 6)% at 12 h postdose compared with the glucose levels prior to oral administration respectively. However, the conventional liposomes and saline have no hypoglycemic effect. The blood glucose levels of the diabetic mice were obviously reduced by TL modified liposomes, the glucose levels were (38 +/- 13)% at 4 h, (50 +/- 15)% at 8 h, (50 +/- 16)% at 12 h respectively.

CONCLUSIONTL modified liposomes promote the oral absorption of insulin due to the specific-site combination on GI cell membrane.

Administration, Oral ; Animals ; Blood Glucose ; metabolism ; Delayed-Action Preparations ; Diabetes Mellitus, Experimental ; blood ; metabolism ; Drug Carriers ; Drug Delivery Systems ; Hypoglycemic Agents ; administration & dosage ; pharmacokinetics ; pharmacology ; Insulin ; administration & dosage ; pharmacokinetics ; pharmacology ; Intestinal Absorption ; drug effects ; Intestine, Small ; metabolism ; Liposomes ; Mice ; Phosphatidylethanolamines ; chemistry ; Plant Lectins ; chemistry ; pharmacology ; Technology, Pharmaceutical ; methods

AIMTo investigate the enhancing effect on insulin absorption through GI. tract in mice by using the Ulex europaeus agglutinin I (UEA1) modified liposomes as the carrier.

METHODSUEA1 modified phosphatidylethanolamine (PE) was prepared by conjugating method of 1-ethyl-3-(3'-dimethylaminopropyl) carbodiimide (EDC), then the modified compound (PE-UEA1) was incorporated into the conventional liposomes of insulin to obtain UEA1 modified liposomes. The agglutination test was performed to examine the UEA1 biological activities after synthesis and modification. When liposomes were applied to healthy mice or diabetic mice at insulin dose of 350 u x kg(-1) orally, the hypoglycemic effect was investigated according to the blood glucose level determination.

RESULTSThe blood glucose levels of the healthy mice reduced by UEA1 modified liposomes were (84 +/- 15)% at 4 h, (78 +/- 11)% at 8 h and (90 +/- 12)% at 12 h after oral administration. The conventional liposomes and saline showed no effect. The blood glucose levels of the diabetic mice reduced by UEA1 modified liposomes were (73 +/- 7)% at 4 h, (74 +/- 9)% at 8 h, (86 +/- 9)% at 12 h after oral administration.

CONCLUSIONThe UEA1 modified liposomes promote the oral absorption of insulin due to the specific-site combination on M cell membrane.

Administration, Oral ; Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; Drug Carriers ; Drug Delivery Systems ; Hypoglycemic Agents ; administration & dosage ; pharmacokinetics ; Insulin ; administration & dosage ; pharmacokinetics ; Intestinal Absorption ; drug effects ; Liposomes ; Mice ; Phosphatidylethanolamines ; chemistry ; Plant Lectins ; chemistry ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Ulex ; chemistry