Enhanced dissolution rates of glibenclamide through solid dispersions on microcrystalline cellulose and mannitol, combined with phosphatidylcholine.

OBJECTIVE: This study aimed to investigate the impact of physical solid dispersions of spray-dried glibenclamide (SG) on the surface of microcrystalline cellulose (MC) and mannitol (M) surfaces, as well as their combination with phosphatidylcholine (P), on enhancing the dissolution rate of glibenclamide (G). METHODS: Solid dispersions were prepared using varying proportions of 1:1, 1:4, and 1:10 for SG on the surface of MC (SGA) and M (SGM), and then combined with P, in a proportion of 1:4:0.02 using spray drying. The particle size, specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and dissolution rate of SGA and SGM were characterized. RESULTS: SEM analysis revealed successful adhesion of SG onto the surface of the carrier surfaces. XRD showed reduced crystalline characteristic peaks for SGA, while SGM exhibited a sharp peaks pattern. Both SGA and SGM demonstrated higher dissolution rates compared to SG and G alone. Furthermore, the dissolution rates of the solid dispersions of SG, MC and P (SGAP), and SG, M, and P (SGMP) were sequentially higher than that of SGA and SGM. CONCLUSIONS: The study suggests that physical solid dispersions of SG on MC and M, along with their combination with P, can effectively enhance the dissolution rate of G. These findings may be valuable in developing of oral solid drug dosage forms utilizing SGA, SGM, SGAP, and SGMP.

N'-(3-Aminopropyl)-N-(3'-(carbamoyl cholesteryl) propyl)-glycine amide liposomes for delivery of pTRAIL-EGFP.

In this study, N'-(3-aminopropyl)-N-(3'-(carbamoyl cholesteryl) propyl)-glycine amide (A) and 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE, D) (AD) liposomes were synthesised at molar ratios of 50:25 (AD5025), 50:50 (AD5050) and 50:75 (AD5075) and complexed with plasmid, pTRAIL-EGFP. AD liposome/pTRAIL-EGFP were evaluated for their complex ability, particle size, polydispersity index, zeta potential, expression of pTRAIL-EGFP, cytotoxicity, cell growth inhibition and apoptosis induction in KB cells. AD liposomes complexed completely with pTRAIL-EGFP at AD liposome/DNA ratios of above 4.5/1. The particle size of AD liposome/pTRAIL-EGFP ranged from 180 ± 8 to 1,072 ± 657 nm depending on the proportion of lipid composition and liposome/DNA ratio. The extent of gene expression of pTRAIL-EGFP via AD liposome/pTRAIL-EGFP was significantly higher than that of the cells treated with pTRAIL-EGFP and depended on the AD liposome/DNA ratio. Cytotoxicity of AD liposomes was dependent on A and D molar ratio. Cell growth inhibition of AD liposome/pTRAIL-EGFP was significantly higher than that of the cells treated with pTRAIL-EGFP. The amount of late apoptotic and dead cells of AD liposome/pTRAIL-EGFP was significantly higher than that of cells treated with pTRAIL-EGFP. From this study that one can conclude that AD liposomes can carry and deliver pTRAIL-EGFP into KB cells resulting in cell growth inhibition and cell death.

Efficient delivery of antisense oligodeoxyribonucleotide g3139 by human serum albumin-coated liposomes.

Human serum albumin (HSA)-coated liposomal formulations were synthesized and evaluated for the delivery of antisense oligodeoxyribonucleotide (ODN) G3139 in KB human oral carcinoma cells. Liposomes composed of dimethyldioctadecyl ammonium bromide/egg phosphatidylcholine/alpha-tocopheryl polyethylene glycol 1000 succinate (58:40:2 molar ratio) complexed with G3139 and coated with HSA were investigated for Bcl-2 downregulating activity. Cellular uptake of HSA-coated liposome-ODN complexes was more efficient than the uncoated liposome-ODN complexes. Treatment of the cells with HSA-coated liposome-ODN complexes resulted in efficient Bcl-2 mRNA downregulation that was approximately 3-fold greater than with uncoated liposomes (p < 0.05) and 6-fold greater than with free ODN. The transfection efficiency of liposome-ODN complexes coated with HSA was dependent on the concentration of HSA used and on the contents of alpha-helix and beta-strand in HSA. HSA-coated liposomes are effective delivery vehicles for antisense ODN.

Effect of depsipeptide on in vitro transfection efficiency of PEI/DNA complexes.

UNLABELLED: The aim of this study was to investigate the effect of depsipeptide on the in vitro transfection efficiency of PEI/DNA complexes. MATERIALS AND METHODS: PEI (polyethylenimine 25K) formed a complex with pcDNA3-CMV-Luc and was investigated for its transfection efficiency in KB human oral carcinoma and Raji human lymphoma cell lines. The transfected cells were then incubated with different concentrations of depsipeptide for 24 h and examined for the transfection efficiency and cell viability. RESULTS: The transfection efficiency in KB cells post-incubated with depsipeptide was not different from the cells transfected with PEI alone. The transfection efficiency in Raji cells post-incubated with 15 nM depsipeptide was significantly increased (p < 0.05) and found to be 76-fold compared to the cells transfected with PEI alone. Depsipeptide had no effect on the cell viability at a concentration of 0.001-1 nM in KB cells and 1-37.5 nM in Raji cells. A high concentration of depsipeptide decreased the cell viability in both cell lines. CONCLUSION: The results demonstrate that PEI/DNA complexes post-incubated with depsipeptide can enhance the transfection efficiency in the Raji human lymphoma cell line. The effect of depsipeptide on cell viability was dose-dependent. This study suggests that depsipeptide may have potential usefulness for gene delivery in patients with lymphoma.

Evaluation of chitosan salts as non-viral gene vectors in CHO-K1 cells.

The aim of this study was to investigate chitosan/DNA complexes formulated with various chitosan salts (CS) including chitosan hydrochloride (CHy), chitosan lactate (CLa), chitosan acetate (CAc), chitosan aspartate (CAs) and chitosan glutamate (CGl). They were assesed for their DNA complexing ability, transfection efficiency in CHO-K1 (Chinese hamster ovary) cells and their effect on cell viability. CHy, CLa, CAc, CAs and CGl, MW 45kDa formed a complex with pcDNA3-CMV-Luc at various N/P ratios. CGl/DNA complexes were formulated with various chitosan molecular weights (20, 45, 200 and 460kDa). The CS/DNA complexes were characterized by agarose gel electrophoresis and investigated for their transfection efficiency in CHO-K1 cells. The cytotoxicity of the complexes was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay in CHO-K1 cells. Gel electrophoresis illustrated that complete complexes formed at N/P ratios above 2 in all CS of MW 45kDa. The transfection efficiency of CS/DNA complexes was dependent on the salt form and MW of chitosan, and the N/P ratio of CS/DNA complexes. Of different CS, the maximum transfection efficiency was found in different N/P ratios. CHy/DNA, CLa/DNA, CAc/DNA, CAs/DNA and CGl/DNA complexes showed maximum transfection efficiencies at N/P ratios of 12, 12, 8, 6 and 6, respectively. Cytotoxicity results showed that all CS/DNA complexes had low cytotoxicity. This study suggests CS have the potential to be used as safe gene delivery vectors.

In vitro gene transfer using cationic vectors, electroporation and their combination.

BACKGROUND: The aim of this study was to investigate the transfection efficiency of cationic vectors (polyethylenimine; PEI25K and lipofectamine), electroporation and their combination in the human cancer cell lines, Raji human lymphoma and KB human oral carcinoma. MATERIALS AND METHODS: Raji human lymphoma and KB human oral carcinoma cell lines were transfected with pcDNA3-CMV-Luc at various N/P ratios of cationic vectors and voltages of electroporation, as well as with a combination of the cationic vectors and electroporation. RESULTS: The major findings were: (a) cationic vectors or electroporation alone increased transfection efficiency; (b) cationic vectors inhibited the transfection efficiency by electroporation. CONCLUSION: Our results demonstrate that cationic vectors and electroporation are feasible and efficient in transfecting human cancer cell lines. However, a combination of cationic vectors and electroporation is ineffective.

Synergistic Inhibition of Human Carcinoma Cell Growth via Co-Delivery of p53 Plasmid DNA and bcl-2 Antisense Oligodeoxyribonucleotide by Cholic Acid-modified Polyethylenimine.

BACKGROUND/AIM: This study investigated the co-delivery of plasmid DNA and antisense oligodeoxyribonucleotide (AS ODN) into carcinoma cells by cholic acid-modified polyethylenimine (PEI-CA). MATERIALS AND METHODS: PEI-CA/plasmid DNA and AS ODN complexes were formulated and evaluated for delivery of plasmid DNA and AS ODN in HeLa cells. The efficiency of co-delivery of plasmid DNA and AS ODN was evaluated by cell growth inhibition using p53 and bcl-2 AS ODN. RESULTS: AS ODN intracellular delivery and green fluorescent protein expression upon cellular transfection were greater than in cells treated with uncomplexed nucleic acids. Treatment of the cells with PEI-CA/p53 plasmid DNA and bcl-2 AS ODN complexes resulted in cell growth inhibition that was greater than that of either PEI-CA/p53 plasmid DNA complexes or PEI-CA/bcl-2 AS ODN complexes alone. CONCLUSION: The co-delivery of p53 plasmid DNA and bcl-2 AS ODN in PEI-CA complexes enhanced therapeutic activities of both p53 plasmid DNA and bcl-2 AS ODN.

Chitosan lactate as a nonviral gene delivery vector in COS-1 cells.

The purpose of this research was to evaluate chitosan lactate (CL) of different molecular weights (MWs) as a DNA complexing agent for its efficiency in transfecting COS-1 cells (green monkey fibroblasts) and its effect on cell viability compared with polyethylenimine (PEI), a commercially available cationic polymer. CL and chitosan base dissolved in dilute acetic acid (chitosan acetate [CA]) of different MWs (20, 45, 200, 460 kDa) and N/P ratios (2:1, 4:1, 8:1, 12:1, 24:1) formed complexes with pSV beta-galactosidase plasmid DNA. The complexes were characterized by agarose gel electrophoresis and investigated for their ability to transfect COS-1 cells compared with PEI. Additionally, the effect of CL on the viability of COS-1 cells was investigated using 3-(4,5-dimethyliazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The binding of CL/DNA and CA/DNA was dependent on chitosan MWs. The N/P ratio of CL to completely form the complex with the DNA was higher than that of CA. Both CL and CA were comparable in transfection efficiencies at an N/P ratio of 12:1, but less efficient than PEI (P < .05). The cell viability in the presence of CL and CA at all MWs was over 90%, whereas that of PEI-treated cells was approximately 50%. These results suggest the advantage of CL for in vitro gene transfection, with the ease of preparation of polymer/DNA complexes and low cytotoxicity.

Co-delivery of plasmid DNA and antisense oligodeoxyribonucleotide into human carcinoma cells by cationic liposomes.

This study aimed to evaluate the co-delivery of cationic liposome/plasmid DNA complexes and cationic liposome/antisense oligodeoxyribonucleotide (AS ODN) complexes in HeLa human cervical carcinoma cells. Dimethyldioctadecyl ammonium bromide (DDAB): dioleoyl phosphatidylethanolamine (DOPE) liposome/plasmid DNA complexes, and DDAB:DOPE liposome/AS ODN complexes were formulated and characterized in terms of agarose gel electrophoretic mobility, particle size and zeta potential. The complexes were evaluated for delivery of pEGFP plasmid DNA and AS ODN in HeLa cells. Cell growth inhibition was evaluated using p53 plasmid DNA and bcl-2 AS ODN, by codelivery of DDAB:DOPE liposome/p53 plasmid DNA and DDAB:DOPE liposome/bcl-2 AS ODN complexes. The particle size of DDAB:DOPE liposome/plasmid DNA complexes, and DDAB:DOPE liposome/AS ODN complexes were 180.6±2.0 to 372.3±2.4 nm, and zeta potentials were -26.7±1.2 to +6.8±0.4 mV, respectively. The AS ODN uptake and green fluorescent protein (GFP) expression upon their co-delivery by DDAB:DOPE liposomes were both high. Treatment of the cells with the co-delivery of DDAB:DOPE liposome/p53 plasmid DNA complexes and DDAB:DOPE liposome/ bcl-2 AS ODN complexes inhibited cell growth to a greater degree than that with either DDAB:DOPE liposome/p53 plasmid DNA complexes or DDAB:DOPE liposome/bcl-2 AS ODN complexes alone. These data suggest that co-delivery of cationic liposome/p53 plasmid DNA and cationic liposome/bcl-2 AS ODN complexes is an effective strategy to achieve enhanced therapeutic activities.

Growth inhibition and chemosensitization of human carcinoma cells by human serum albumin-coated liposomal antisense oligodeoxyribonucleotide against bcl-2.

Previous study has shown human serum albumin (HSA) coated liposomes can deliver bcl-2 antisense oligodeoxyribonucleotide (ODN) into KB carcinoma cells, and decrease bcl-2 mRNA and protein expression level. In the current study, cell growth inhibition and chemosensitization of KB cells were evaluated. Liposomes composed of dimethyldioctadecyl ammonium bromide/egg phosphatidylcholine/α-tocopheryl polyethylene glycol 1000 succinate (58:40:2 molar ratio) complexed with bcl-2 antisense ODN and coated with HSA were examined for cell growth inhibition and sensitization to a commonly used chemotherapeutic drug, doxorubicin. HSA-coated liposome-ODN complexes effectively inhibited cell growth in the range of ODN concentration of 0.45-7.2 µM. Upon posttreatment with doxorubicin, the cytotoxicity was further significantly increased compared to the ODN complexes alone. The cytotoxicity was dependent on antisense ODN concentration, incubation time and doxorubicin concentration, and relatively independent on HSA concentration. This study suggests that HSA-coated liposomes are effective delivery vehicles for antisense ODN with potential therapeutic application and can be effectively combined with doxorubicin.

Disulfide-linked liposomes: effective delivery vehicle for Bcl-2 antisense oligodeoxyribonucleotide G3139.

BACKGROUND: Disulfide-linked oligodeoxyribonucleotide (ODN) liposomes were formulated and evaluated for the delivery of antisense ODN G3139 in KB human oral carcinoma cells. MATERIALS AND METHODS: Liposomes composed of 1,2-di-(9Z-octadecenoyl)-3-trimethylammo-nium-propane (DOTAP)/egg phosphatidylcholine/alpha-tocopheryl polyethylene glycol 1000 succinate were incorporated with hydrophobized disulfide-linked ODN. Disulfide-linked ODN liposomes were characterized for their size, ODN intracellular delivery, Bcl-2 mRNA and protein expression, growth inhibition, and chemosensitization. RESULTS: Intracellular delivery of ODN with disulfide-linked ODN liposomes was more efficient than that with non-liposomal hydrophobized disulfide-linked ODN. Treatment of the cells with disulfide-linked ODN liposomes resulted in efficient Bcl-2 down-regulation greater than that with hydrophobized disulfide-linked ODN and consistent with that of cellular growth inhibition and the sensitization to daunorubicin in KB cells. Disulfide-linked ODN liposomes exhibited superior colloidal stability during 5-week storage. CONCLUSION: Disulfide-linked liposomes are effective delivery vehicles for antisense ODN.

Transferrin-conjugated lipid-coated PLGA nanoparticles for targeted delivery of aromatase inhibitor 7alpha-APTADD to breast cancer cells.

Transferrin (Tf)-conjugated lipid-coated poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles carrying the aromatase inhibitor, 7alpha-(4'-amino)phenylthio-1,4-androstadiene-3,17-dione (7alpha-APTADD), were synthesized by a solvent injection method. Formulation parameters including PLGA-to-lipid, egg PC-to-TPGS, and drug-to-PLGA ratios and aqueous-to-organic phase ratio at the point of synthesis were optimized to obtain nanoparticles with desired sizes and drug loading efficiency. The optimal formulation had a drug loading efficiency of 36.3+/-3.4%, mean diameter of 170.3+/-7.6nm and zeta potential of -18.9+/-1.5mV. The aromatase inhibition activity of the nanoparticles was evaluated in SKBR-3 breast cancer cells. IC(50) value of the Tf-nanoparticles was ranging from 0.77 to 1.21nM, and IC(50) value of the nanoparticles was ranging from 1.90 to 3.41nM (n=3). The former is significantly lower than the latter (p<0.05). These results suggested that the aromatase inhibition activity of the Tf-nanoparticles was enhanced relative to that of the non-targeted nanoparticles, which was attributable to Tf receptor (TfR) mediated uptake. In conclusion, Tf-conjugated lipid-coated PLGA nanoparticles are potential vehicles for improving the efficiency and specificity of therapeutic delivery of aromatase inhibitors.

Antioxidative and neuroprotective activities of extracts from the fruit hull of mangosteen (Garcinia mangostana Linn.).

OBJECTIVE: The aim of this study was to investigate the antioxidative and neuroprotective activities of various extracts from the fruit hull of mangosteen (Garcinia mangostana Linn., GM). MATERIALS AND METHODS: Four extracts: water, 50% ethanol, 95% ethanol and ethyl acetate, were used. The antioxidative activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging assay at extract concentrations of 1, 10, 50 and 100 microg/ml. Based on the free radical scavenging activity of the extracts, two (water and 50% ethanol) were selected for their protective activity in NG108-15 neuroblastoma cells against H(2)O(2)-induced oxidative stress and for cell viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. RESULTS: All extracts exhibited antioxidative activity. The water and 50% ethanol extracts showed high free-radical scavenging activity with IC(50) values of 34.98 +/- 2.24 and 30.76 +/- 1.66 microg/ml, respectively. Both water and 50% ethanol extracts exhibited neuroprotective activity on NG108-15 cells. The highest activity was observed at the concentration of 50 microg/ml for both the water and 50% ethanol extracts. For cytotoxicity test, none of the extracts was toxic to the cells except at the high concentration of 100 microg/ml. CONCLUSIONS: These results suggest that the water and 50% ethanol extracts from the fruit hull of GM may be potent neuroprotectants.