An HPLC method for the pharmacokinetic study of daidzein-loaded nanoparticle formulations after injection to rats

This study was aimed at developing a simple HPLC method for the detection of daidzein in rat plasma. Daidzein was extracted from rat plasma with ethylparaben as internal standards (IS). Chromatographic separation of daidzein and IS was achieved by a Dikma Dimonsil C18 column (200 mm × 4.6mm) with the mobile phase consisting of methanol-water (55:45, v/v) at a flow rate of 1.0 mL/min. The injection volume was 20 μL and the detecting wavelength was 249 nm. The calibration curve was linear over a concentration range from 0.05 to 5 μg/mL, and the accuracy was within a range of 93.4-126.2%. This HPLC method was applied successfully to the pharmacokinetic study of two kinds of daidzein-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (D-NPs) and daidzein suspension after intravenous injection in rats. Significant differences in main pharmacokinetic parameters of daidzein suspension and D-NPs were observed.     

Determination of sinefungin in rat plasma by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatographic method for the determination of sinefungin, a new antiprotozoal drug, in rat plasma has been developed and validated. Sample preparation was performed at 4°C by deproteinization with acetonitrile. Vidarabine was used as an internal standard. Both sinefungin and vidarabine were separated on a C₁₈ column with a mobile phase of ammmonium dihydrogenphosphate-acetonitrile (95:5, v/v) and detected by ultraviolet absorbance at 260 nm. Recoveries of sinefungin from plasma were 75 ± 3.2% and 81 ± 4.8% following dosage at concentrations of 10 μg/ml and 30 μ/ml, respectively. Using 25- μl of rat plasma the limit of quantitation was 1 μg/ml sinefungin, and the assay was linear from 1 to 30 μg/ml. This method appears sensitive enough to be used in further pharmacokinetic studies of sinefungin in animal models.     

载多西紫杉醇脂质微泡对人肝癌HepG2细胞抑制作用的体外研究

目的：观察自制载多西紫杉醇脂质微泡联合超声对人肝癌HepG2细胞的抑制作用。方法：通过薄膜分散法制备载多西紫杉醇脂质微泡,观察其形态,测定粒径大小、包封率、载药量及稳定性等性质;将人肝癌HepG2细胞随机分为5组,对照组、多西紫杉醇组（DOC组）、多西紫杉醇联合超声组（DOC＋US组）、载多西紫杉醇脂质微泡组（DLLM组）、载多西紫杉醇脂质微泡联合超声组（DLLM＋US组）,CCK-8法检测细胞毒性,倒置显微镜观察细胞凋亡的形态,DAPI荧光染色法观察凋亡细胞核的改变。结果：载多西紫杉醇脂质微泡形态光滑圆整,无黏连;粒径分布范围为170~590 nm,平均粒径为350 nm;Zeta电位为-5.2 mV;微泡的包封率为80.0%,载药量为18.5%;4℃条件下保存14天性质稳定;DLLM＋US组较其他各组对肿瘤细胞有更为明显的抑制增殖及诱导凋亡效应（P〈0.01）。结论：自制载多西紫杉醇脂质微泡粒径小,包封率高,稳定性好,此微泡联合超声对人肝癌HepG2细胞有明显抑制作用,载多西紫杉醇脂质微泡有望成为一种新型抗肿瘤给药途径。     

Simultaneous quantification of tracheloside and trachelogenin in rat plasma using liquid chromatography/tandem mass spectrometry

We developed and validated a quantitative method for simultaneously determining the concentrations of tracheloside and trachelogenin in rat plasma. Plasma samples were prepared by liquid-liquid extraction with ethyl acetate. Isocratic chromatographic separation was performed on a reversed-phase Diamonsil C(18) column (4.6×200 mm, 5 μm). The mobile phase consisted of methanol and 10mM aqueous ammonium formate (80:20, v/v). Analyte detection was achieved by positive electrospray ionization (ESI) tandem mass spectrometry. Calibration was performed by internal standardization with glipizide, and regression curves ranging from 0.625 to 625 ng/mL were constructed for both the analytes. The intra- and inter-day precision values were below 8%, and accuracy ranged from -5.33% to 2.53% in all quality control samples. In this study, the validated method was successfully applied to determine the pharmacokinetic profile of tracheloside and trachelogenin in rat plasma after oral and intravenous administration of trachelospermi total lignans.     

Development and Validation of HPLC Method for Determination of Sodium Copper Chlorophyllin – A Food Colorant and Its Application in Pharmacokinetic Study

A simple, accurate, and precise bioanalytical method was developed and validated for the determination of pharmacokinetic parameters of sodium copper chlorophyllin, a USFDA approved food additive and colorant in rat plasma. The column used was Luna^® C₁₈ 250×4.6 mm, 100 Å, having particle size 4.5 μm, and the mobile phase used was methanol (MeOH), and 10 mM ammonium acetate buffer in the ratio of 90 : 10, the flow rate was 1 ml/min, and the injection volume of 20 μL. The retention time of sodium copper chlorophyllin was obtained at 9 min. The method was found to be linear at the range of 0.50–8.00 μg mL^?1.     

High-performance liquid chromatography analysis of a novel small-molecule, anti-cancer drug, Palomid 529, in human and mouse plasma and in mouse tissue homogenates

Palomid 529 (8-(1-Hydroxy-ethyl)-2-methoxy-3-(4-methoxy-benzyloxy)-benzo[c]chromen-6-one), is a novel non-steroidal small-molecule drug, which inhibits both mTORC1 and mTORC2 assembly, and elicits both anti-angiogenic and direct anti-tumor effects in vivo. We have developed and validated a sensitive and selective method for the quantification of Palomid 529 in human and mouse plasma and in a range of mouse tissue samples. Sample pretreatment involved liquid-liquid extraction with tert-butyl methyl ether yielding a recovery of >75%. Palomid 529 and the internal standard Palomid 545 were separated using a GraceSmart RP18 column (2.1 mm × 150 mm) packed with 5 μm C-18 material and a mobile phase comprised of 50% (v/v) acetonitrile and 50% (v/v) water delivered at a flow rate of 0.2 ml/min, and were detected by UV absorbance at a wavelength of 315 nm. Within the linear range of the calibration curve (10-10,000 ng/ml), acceptable accuracy and precision was achieved for all tested matrices. The validation results show that the method was selective and reproducible. Palomid 529 was stable in plasma upon 3 repeated freeze-thaw cycles and during storage for up to 24h at ambient temperature. However, pre-treated samples waiting for HPLC analyses need to be kept under dimmed light conditions at ambient temperature since a significant degradation of both Palomid 529 and Palomid 545 was observed when exposed to light. A pilot pharmacokinetic study in mice demonstrated the applicability of this method for pharmacokinetic purposes. Even at a low dose of 5.4 mg/kg this assay was still sensitive enough to determine the drug concentration in plasma samples obtained up to 24h after administration.     

An HPLC method for the pharmacokinetic study of vincristine sulfate-loaded PLGA-PEG nanoparticle formulations after injection to rats

The aim of this study is to develop a simple and applicable HPLC method for the detection of vincristine in rat plasma after administration of poly(lactic-co-glycolic acid)-poly(ethylene glycol) (PLGA-PEG) nanoparticles loaded with vincristine sulfate (VCR). Vincristine was extracted from rat plasma and vinblastine sulfate was chosen as the internal standard (IS). Chromatographic separation of VCR and IS was achieved by a Dikma Dimonsil C?? column (200 mm×4.6 mm) with the mobile phase consisting of 0.02 M sodium dihydrogen phosphate-methanol (36:64, v/v, pH=4.7) at a flow rate of 1.0 mL/min. The ultraviolet detection wavelength was set at 276 nm. The calibration curve was linear over a concentration range of 0.05-5.0 μg/mL. The intra-day and inter-day accuracy for three quality controls (QC) samples was 93.48-107.74% and 92.61-96.58%, respectively; the precision was less than 9%. The average method recoveries for vincristine from spiked plasma at all QC levels were over 83%; and extraction recoveries were between 66 and 70%. Vincristine was stable in rat plasma for one month at -80°C, for 8 h at room temperature, as well as during three freeze-thaw cycles. This HPLC method was applied successfully to the pharmacokinetic study of vincristine in rats after a single intravenous injection of VCR in physiological saline (F-VCR) solution, VCR-loaded PLGA-mPEG nanoparticles with (NP1) and PLGA-PEG-folate nanoparticles (NP2) suspension, respectively. There were significant differences in main pharmacokinetic parameters between F-VCR and the nanoparticles. Both kinds of VCR-loaded nanoparticles displayed improved pharmacokinetic profiles.     

Determining the pharmacokinetics of psilocin in rat plasma using ultra-performance liquid chromatography coupled with a photodiode array detector after orally administering an extract of Gymnopilus spectabilis

This study established ultra-performance liquid chromatography coupled with a photodiode array detector for determining psilocin and its pharmacokinetics in rat plasma after orally administering an extract of Gymnopilus spectabilis. The extract was separated on an ODS C18 column (2.3 μm, 100 mm × 2.1 mm I.D.) by gradient elution with (A) water containing 50mM AcONH(4) and (B) acetonitrile. The wavelength was set at 265 nm and the injection volume was 10 μL. Under these conditions, the calibration curve was linear over the concentration range 0.2-20 μg/mL with a correlation coefficient of r(2)=0.9992. The inter- and intraday precision levels were less than 7% and the accuracies (%) were within the range 92.0-102.5%. The method was sufficiently valid to be applied to a pharmacokinetics study of psilocin in rat plasma. The pharmacokinetic parameters of psilocin in rat plasma after the oral administration of a G. spectabilis extract were as follows: C(max), 0.43 ± 0.12 μg/mL; T(max), 90 ± 2.1 min; AUC(0→t), 1238.3 ± 96.4 (μg/mL) min; and T(1/2), 117.3 ± 40.3 min.     

Application of a high-performance liquid chromatographic assay for the neuromuscular blocker gallamine to analysis of rat plasma, muscle and microdialysate samples

A reliable high-performance liquid chromatographic method has been validated for determination of gallamine in rat plasma, muscle tissue and microdialysate samples. A C₁₈ reversed-phase column with mobile phase of methanol and water containing 12.5 mM tetrabutyl ammonium (TBA) hydrogen sulphate (22:78, v/v) was used. The flow-rate was 1 ml/min with UV detection at 229 nm. Sample preparation involved protein precipitation with acetonitrile for plasma and muscle tissue homogenate samples. Microdialysate samples were injected into the HPLC system without any sample preparation. Intra-day and inter-day accuracy and precision of the assay were <13%. The limit of quantification was 1 μg/ml for plasma, 1.6 μg/g for muscle tissue and 0.5 μg/ml for microdialysate samples. The assay was applied successfully to analysis of samples obtained from a pharmacokinetic study in rats using the microdialysis technique.     

Quantitation of itraconazole in rat heparinized plasma by liquid chromatography–mass spectrometry

A liquid chromatographic–mass spectrometric (LC–MS) assay was developed and validated for the determination of itraconazole (ITZ) in rat heparinized plasma using reversed-phase HPLC combined with positive atmospheric pressure ionization (API) mass spectrometry. After protein precipitation of plasma samples (0.1 ml) with acetonitrile containing nefazodone as an internal standard (I.S.), a 50-μl aliquot of the supernatant was mixed with 100 μl of 10 mM ammonium formate (pH 4.0). An aliquot of 25 μl of the mixture was injected onto a BDS Hypersil C₁₈ column (50×2 mm; 3 μm) at a flow-rate of 0.3 ml/min. The mobile phase comprising of 10 mM ammonium formate (pH 4) and acetonitrile (60:40, v/v) was used in an isocratic condition, and ITZ was detected in single ion monitoring (SIM) mode. Standard curves were linear (r²≥0.994) over the concentration range of 4–1000 ng/ml. The mean predicted concentrations of the quality control (QC) samples deviated by less than 10% from the corresponding nominal values; the intra-assay and inter-assay precision of the assay were within 8% relative standard deviation. Both ITZ and I.S. were stable in the injection solvent at room temperature for at least 24 h. The extraction recovery of ITZ was 96%. The validated assay was applied to a pharmacokinetic study of ITZ in rats following administration of a single dose of itraconazole (15 mg/kg).     

白藜芦醇脂质载体制备及体外抗氧化活性测定

白藜芦醇是一种天然功能性成分，具有美白、抗氧化等功效，可用于治疗改善多种皮肤病变，延缓细胞衰老。白黎芦醇在水中的溶解度低，稳定性较差，影响了其在医药及化妆品领域的应用。本研究制备了负载白黎芦醇的纳米结构脂质载体，提高了白藜芦醇的水中分散度、稳定性和功能活性。通过热高压均质法制备了白黎芦醇纳米结构脂质载体（NLC），确定了以单硬脂酸甘油酯为固态脂质，油酸为液态脂质，其比例为1：1，4%吐温80为乳化剂，均质压力为600 bar，循环3次时得到的白藜芦醇脂质载体粒径为179 nm，此时药物包封率为85.33%。MTT实验和ROS清除实验结果也表明白藜芦醇脂质载体浓度低于100 μmol·L^-1时都未对细胞产生明显毒性，并且有优于白藜芦醇原料药的抗氧化活性。     

Simultaneous determination of cefdinir and cefixime in human plasma by RP-HPLC/UV detection method: Method development, optimization, validation, and its application to a pharmacokinetic study

A novel isocratic reversed-phase high performance liquid-chromatography/ultraviolet detection method for simultaneous determination of cefdinir and cefixime in human plasma was developed and validated after optimization of various chromatographic conditions and other experimental parameters. Sample preparation based on a simple extraction procedure consisting of deproteination and extraction with 3 parts of 6% trichloroacetic acid aqueous solution followed by volume make up with the aqueous component of the mobile phase obtained best recoveries of the two analytes. Samples were separated on a Supelco Discovery HS C(18) (150 mm × 4.6 mm, 5 μm) analytical column protected by a Perkin Elmer C(18) (30 mm × 4.6 mm, 10 μm) guard cartridge. The mobile phase, methanol/acetonitrile (50/50, v/v):0.05% trifluoroacetic acid (19:81, v/v), operated at 50°C column oven temperature was pumped at a flow rate of 2.0 mL min(-1) and the column eluents were monitored at a wavelength of 285 nm. When Sample was injected into the Perkin Elmer high performance liquid-chromatography system through Rheodyne manual (or auto-sampler) injector equipped with 20 μL loop, separation was achieved within 4 min. The present method demonstrated acceptable values for selectivity, linearity within the expected concentration range (0.004-5.0 μg mL(-1); r(2)>0.999 for both analytes), recovery (>95% for cefdinir and >96% for cefixime), precision (%RSD<2.0 for cefdinir and <2.2 for cefixime), sensitivity (limit of detection: 1 ng mL(-1) and lower limit of quantification: 4 ng mL(-1) for both analytes), stability of solutions, and robustness. The method was efficiently applied to a pharmacokinetic study in healthy volunteers.     

Highly efficient system to deliver taxanes into tumor cells: docetaxel-loaded chitosan oligomer colloidal carriers

Chitosan (CS) colloidal carriers, which consist of an oily core and a CS coating, were developed to facilitate a controlled intracellular delivery of docetaxel. The systems presented a particle size of <200 nm and a positive surface charge. As shown by the flow cytometry analysis, fluorescent CS carriers were rapidly internalized by human tumor cells. Fluorescence was observed in more than 80% of MCF7 (human breast adenocarcinoma) and almost 100% of A549 (human lung carcinoma) cells when a 2 h treatment with fluorescent CS carriers was given. A total of 24 h after treatment, docetaxel-loaded CS carriers had an effect on cell proliferation that was significantly greater than that of free docetaxel. These results indicate that docetaxel remains fully active upon its encapsulation into the colloidal carriers and that these systems actively transport docetaxel into cancer cells and, thus, result in a significant increase in its antiproliferative effect.     

Sensitive gas-liquid chromatographic method for the assay of the neuroleptic drug cis(Z)-flupentixol in human serum or plasma

A gas-liquid chromatographic (GLC) assay suitable for the analysis of the cis(Z)-stereoisomer of the antipsychotic drug flupentixol in human serum or plasma was developed. The minimal quantifiable concentration was 0.5 ng/ml and the day-to-day coefficient of variation was 11.2% at 1 ng/ml and 8.7% at 10 ng/ml. Following addition of perphenazine as the internal standard (I.S.) and aqueous NaOH, samples (2 ml) are extracted with n-hexane-isoamyl alcohol (98.5:1.5, v/v) (solvent), back-extracted to 0.1 M HCl and after one washing-step and addition of aqueous NaOH again extracted into 100 μl solvent. After evaporation to dryness, the extract is reconstituted in 20 μl solvent and evaporated to approximative 10 μl. A 4-μl aliquot is injected cool on-column onto the GLC system. A gas chromatograph HP 5890 with on-column injection port, nitrogen-phosphorus detector (NPD), a HP-1 25 m × 0.32 mm I.D., 0.5 μm capillary and hydrogen (3 ml/min, automated pressure control) as the carrier gas was applied. The negative influence of light on the assay was measured and discussed. The suitability of this method for clinical pharmacokinetic studies and therapeutic drug monitoring (TDM) was determined by the analysis of serum samples of 12 schizophrenic patients.     

Genome-wide location analysis reveals an important overlap between the targets of the yeast transcriptional regulators Rds2 and Adr1

A simple and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the quantification of tetrahydrobiopterin (BH4) and dopamine in rat brain using epsilon-acetamidocaproic acid (AACA) as an internal standard. Proteins in the samples were precipitated with acetonitrile and then the supernatants were separated by a Sepax Polar-Imidazole (2.1 × 100 mm, i.d., 3 μm) column using a mixture of 10mM ammonium formate in acetonitrile/water (75:25, v/v) as the mobile phase at a flow rate of 300 μl/min. Quantification was performed on a triple quadrupole mass spectrometer employing electrospray ionization with the operating conditions as multiple reaction monitoring (MRM) and positive ion mode from m/z 242.1 → 166.0 for BH4, m/z 154.1 → 90.0 for dopamine and m/z 174.1 → 114.0 for AACA (IS). The total chromatographic run time was for 5.5 min. The method was validated for the analysis of samples: the limit of detection was 10 ng/g. The calibration curve was linear between 10-2000 ng/g for BH4 (r(2)=0.995) and 10-5000 ng/g for dopamine (r(2)=0.997) in the rat brain. Thus, good correlated LC-ESI/MS/MS results were obtained and found to be a powerful tool for the quantitative analysis of BH4 and dopamine in the rat brain.     

A sensitive LC-MS/MS method for the quantitative analysis of the Echinacea purpurea constituent undeca-2-ene-8,10-diynoic acid isobutylamide in human plasma

Echinacea purpurea is one of the most popular herbal medicines and is known for its immunostimulatory effects. Alkylamides are the main lipophilic components of E. purpurea that contribute to its pharmacological actions. For quantification in human plasma of one of these alkylamides, undeca-2-ene-8,10-diynoic acid isobutylamide, a sensitive LC-MS/MS assay has been developed and validated. Plasma samples were pretreated using liquid-liquid extraction with a mixture of diethyl ether and n-hexane (50:50, v/v). Dried extracts were reconstituted in 50 μL of acetonitrile-water (50:50, v/v) after which 15 μL of sample was injected into the HPLC system. HPLC was performed using a Polaris 3 C18-A column (50 mm×2 mm ID) and isocratic elution with acetonitrile-water (50:50, v/v) containing 0.1% formic acid at a flow rate of 0.3 mL/min. Subsequently, electrospray ionization in the positive ion mode followed by tandem mass spectrometry was performed for detection. The total run time was 3 min. The assay was validated over a concentration range from 0.05 to 50 ng/mL for undeca-2-ene-8,10-diynoic acid isobutylamide, with 0.05 ng/mL being the lower limit of quantification using 1.0 mL plasma samples. Inter-assay inaccuracy (±12.7%), within-day and between-day precisions (CV≤8.23%) were acceptable. Further, undeca-2-ene-8,10-diynoic acid isobutylamide was found to be chemically stable under relevant conditions. Finally, the applicability of this assay has been successfully demonstrated in a pharmacokinetic experiment in which a human volunteer ingested a commercial extract of E. purpurea.     

Effect of prolyl-leucyl-glycinamide and α-melanocyte-stimulating hormone on levorphanol-induced analgesia,tolerance and dependence

Prolyl-leucyl-glycinamide (PLG) at a low dose (10 ng/mouse) administered by an intracerebroventricular (i.c.v.) injection did not affect levorphanol analgesia, but PLG at higher doses (10 and 100 μg/mouse) and α-melanocyte-stimulating hormone (α-MSH) (10 ng/ mouse) antagonized levorphanol analgesia. Development of levorphanol tolerance was facilitated by 10 ng/mouse of PLG, unaffected by 10 μg/mouse of PLG, but antagonized by 100 μg/mouse of PLG and 10 ng/mouse of α-MSH. The effect of PLG on levorphanol dependence was assessed by changes in body weight and temperature during naloxone-induced withdrawal. PLG (10 ng/mouse) facilitated the development of levorphanol dependence, but 10 μg/mouse of PLG had no effect. PLG (100 μg/mouse) antagonized development of levorphanol dependence. PLG at doses of 10 and 100 μg/mouse precipitated withdrawal in levorphanol-dependent mice. α-MSH (10 ng/mouse) antagonized development of levorphanol dependence as evidenced by an increase in the ED50 of naloxone required to induce withdrawal jumping. These results indicate that PLG and α-MSH affected levorphanol-induced analgesia, tolerance and dependence in a qualitatively similar manner to their effect on morphine-induced analgesia, tolerance and dependence.     

Column-switching high-performance liquid chromatographic method for the determination of zaltoprofen in rat plasma

A direct injection column-switching high-performance liquid chromatography (HPLC) method was developed and validated for quantification of zaltoprofen in rat plasma. Following dilution with mobile phase A, i.e. acetonitrile-10mM potassium phosphate buffer (pH 6.8) (12:88, v/v) samples were directly injected to the pre-column without sample pre-purification step. After endogenous plasma components were eluted to waste, the system was switched and the analyte was eluted to the trap column. Zaltoprofen was then back-flushed to the analytical column for separation with mobile phase B, i.e. acetonitrile-10mM potassium phosphate buffer (pH 6.8) (35:65, v/v) and quantification with an ultraviolet detector at 230 nm. The calibration curve was linear in the concentration range of 40-5000 ngmL(-1). This method has been fully validated and shown to be specific, accurate and precise. The method is simple, rapid and the sample preparation is minimal and appears to be useful for the pharmacokinetic study of zaltoprofen.     

Measurement of amoxicillin in plasma and gastric samples using high-performance liquid chromatography with fluorimetric detection

A rapid, selective and sensitive HPLC assay has been developed for the routine analysis of amoxicillin in rat plasma, gastric juice aspirate and gastric tissue which is applicable to low concentrations of amoxicillin (<1 microg mL(-1)) or small sample volumes. Amoxicillin was converted, via an internal rearrangement, to form a fluorescent product which was subsequently recovered using liquid-liquid extraction. A Kromasil ODS 3 microm (150 x 3.2 mm I.D.) column was maintained at 40 degrees C and used with a mobile phase consisting of methanol-water (55:45, v/v). Fluorimetric detection was at an lambda(ex) of 365 nm and an lambda(em) of 445 nm. The limits of quantitation for amoxicillin were 0.1 microg mL(-1) for gastric juice aspirate (500 microL), 0.5 microg mL(-1) for plasma (50 microL) and 0.075 microg g(-1) for gastric tissue (250 mg). The method was linear up to at least 15 microg mL(-1) in gastric juice aspirate, up to 200 microg mL(-1) in plasma and up to 100 microg g(-1) in gastric tissue, with inter- and intra-day RSDs being less than 19%. The assay has been applied to the measurement of amoxicillin in rat plasma, gastric juice aspirate and gastric tissue for pharmacokinetic studies in individual rats.     

Targeting cyclin B1 through peptide-based delivery of siRNA prevents tumour growth

The development of short interfering RNA (siRNA), has provided great hope for therapeutic targeting of specific genes responsible for patholological disorders. However, the poor cellular uptake and bioavailability of siRNA remain a major obstacle to their clinical development and most strategies that propose to improve siRNA delivery remain limited for in vivo applications. In this study, we report a novel peptide-based approach, MPG-8 an improved variant of the amphipathic peptide carrier MPG, that forms nanoparticles with siRNA and promotes their efficient delivery into primary cell lines and in vivo upon intra-tumoral injection. Moreover, we show that functionalization of this carrier with cholesterol significantly improves tissue distribution and stability of siRNA in vivo, thereby enhancing the efficiency of this technology for systemic administration following intravenous injection without triggering any non-specific inflammatory response. We have validated the therapeutic potential of this strategy for cancer treatment by targeting cyclin B1 in mouse tumour models, and demonstrate that tumour growth is compromised. The robustness of the biological response achieved through this approach, infers that MPG 8-based technology holds a strong promise for therapeutic administration of siRNA.