Poly-ε-caprolactone based nanoparticles for delivery of genistein in melanoma treatment

Abstract We developed poly-ε-caprolactone (PCL)-based nanoparticles containing D-α-tocopherol polyethylene glycol-1000 succinate (TPGS) or Poloxamer 407 as stabilizers to efficiently encapsulate genistein (GN). Two formulations, referred to as PNTPGS and PNPol, were prepared using nanoprecipitation. They were characterized by size and PDI distribution, zeta potential, nanoparticle tracking analysis (NTA), GN association (AE%), infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). PNTPGS-GN exhibited a particle size of 141.2 nm, a PDI of 0.189, a zeta potential of -32.9 mV, and an AE% of 77.95%. PNPol-GN had a size of 146.3 nm, a better PDI than PNTPGS-GN (0.150), a less negative zeta potential (-21.0 mV), and an AE% of 68.73%. Thermal and spectrometric analyses indicated that no new compounds were formed, and there was no incompatibility detected in the formulations. Cellular studies revealed that Poloxamer 407 conferred less toxicity to PCL nanoparticles. However, the percentage of uptake decreased compared to the use of TPGS, which exhibited almost 80% cellular uptake. This study contributes to the investigation of stabilizers capable of conferring stability to PCL nanoparticles efficiently encapsulating GN. Thus, the PCL nanoparticle proposed here is an innovative nanomedicine for melanoma therapy and represents a strong candidate for specific pre-clinical and in vivo studies.

Preparation of an ophthalmic formulation of TPGS-modified insulin-loaded liposomes and its in vitro corneal permeation and pharmacokinetics in rabbit eyes / 南方医科大学学报

OBJECTIVE@#To prepare vitamin E polyethylene glycol 1000 succinate (TPGS)-modified insulin-loaded liposomes (T-LPs/INS) and evaluate its safety, corneal permeability, ocular surface retention and pharmacokinetics in rabbit eyes.@*METHODS@#The safety of the preparation was investigated in human corneal endothelial cells (HCECs) using CCK8 assay and live/dead cell staining. In the ocular surface retention study, 6 rabbits were randomized into 2 equal groups for application of fluorescein sodium dilution or T-LPs/INS labeled with fluorescein in both eyes, which were photographed under cobalt blue light at different time points. In the cornea penetration test, another 6 rabbits divided into 2 groups for application of Nile red diluent or T-LPs/INS labeled with Nile red in both eyes, after which the corneas were harvested for microscopic observation. In the pharmacokinetic study, 2 groups of rabbits (n=24) were treated with eye drops of T-LPs/INS or insulin, and the aqueous humor and cornea were collected at different time points for measurement of insulin concentrations using enzyme linked immunosorbent assay. DAS2 software was used to analyze the pharmacokinetic parameters.@*RESULTS@#The prepared T-LPs/INS showed good safety in cultured HCECs. Corneal permeability assay and fluorescence tracer ocular surface retention assay demonstrated a significantly higher corneal permeability of T-LPs/INS with a prolonged drug residence in the cornea. In the pharmacokinetic study, insulin concentrations in the cornea at 6, 15, 45, 60, and 120 min (P < 0.01) and in the aqueous humor at 15, 45, 60, and 120 min after dosing were significantly higher in T-LPs/INS group. The changes in insulin concentrations in the cornea and aqueous humor were consistent with a two-compartment model in T-LPs/INS group and with the one-compartment model in the insulin group.@*CONCLUSION@#The prepared T-LPs/INS shows an improved corneal permeability, ocular surface retention capacity and eye tissue concentration of insulin in rabbits.

Preparation and Preliminary Evaluation of Paclitaxel-loaded TPGS-CR Polymeric Micelles / 中国药学杂志

OBJECTIVE: To prepare paclitaxel loaded D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)-modified carboxymethyl chitosan-rhein polymeric micelles (PTX/TPGS-CR PMs) and preliminarily evaluate their performance. METHODS: PTX/TPGS-CR PMs was prepared by dialysis method, and the preparation procedure of PTX/TPGS-CR PMs was optimized by single factor with the drug loading, encapsulation rate and particle size as the indicators, then the optimized preparation procedure was verified. The safety of PTX/TPGS-CR PMs was initially investigated by the hemolysis test and the vascular irritation test. The cytotoxicity of PTX/TPGS-CR PMs in Hela cells was studied by MTT assay. Cell uptake experiments were performed by laser confocal microscopy and flow cytometry to investigate the uptake of PTX/TPGS-CR PMs by Hela cells. RESULTS: The particle size and PDI of PTX/TPGS-CR PMs prepared by the optimized preparation were (197.3±4.4) nm and (0.131±0.021), respectively. The Zeta potential was (-31.8±0.5) mV. The drug loading and encapsulation efficiency were (48.20±3.03)% and (87.26±4.91)%, respectively. The hemolytic test results showed that the hemolysis rate was less than 1.71%. No obvious irritation was observed after intravenous injection. The cytotoxicity of PTX/TPGS-CR PMs in Hela cells was concentration-and time-dependent. Cell uptake experiments showed that PTX/TPGS-CR PMs could be efficiently uptake by Hela cells. CONCLUSION: The PTX/TPGS-CR PMs has high drug loading and encapsulation efficiency, good safety. And they exhibite slightly better antitumor activity in vitro than Taxol®.

Enhanced water solubility, antioxidant activity, and oral absorption of hesperetin by D-α-tocopheryl polyethylene glycol 1000 succinate and phosphatidylcholine / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Hesperetin, an abundant bioactive component of citrus fruits, is poorly water-soluble, resulting in low oral bioavailability. We developed new formulations to improve the water solubility, antioxidant activity, and oral absorption of hesperetin. Two nano-based formulations were developed, namely hesperetin-TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) micelles and hesperetin-phosphatidylcholine (PC) complexes. These two formulations were prepared by a simple technique called solvent dispersion, using US Food and Drug Administration (FDA)-approved excipients for drugs. Differential scanning calorimetry (DSC) and dynamic light scattering (DLS) were used to characterize the formulations' physical properties. Cytotoxicity analysis, cellular antioxidant activity assay, and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations. The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility, which increased to 21.5- and 20.7-fold, respectively. The hesperetin-TPGS micelles had a small particle size of 26.19 nm, whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm. In addition, the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2- and 3.9-fold, respectively. Importantly, the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration (Cmax) from 2.64 μg/mL to 20.67 and 33.09 μg/mL and also increased the area under the concentration-time curve of hesperetin after oral administration to 16.2- and 18.0-fold, respectively. The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin, indicating these formulations' potential applications in drugs and healthcare products.

Enhanced water solubility, antioxidant activity, and oral absorption of hesperetin by D-α-tocopheryl polyethylene glycol 1000 succinate and phosphatidylcholine / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Hesperetin, an abundant bioactive component of citrus fruits, is poorly water-soluble, resulting in low oral bioavailability. We developed new formulations to improve the water solubility, antioxidant activity, and oral absorption of hesperetin. Two nano-based formulations were developed, namely hesperetin-TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) micelles and hesperetin-phosphatidylcholine (PC) complexes. These two formulations were prepared by a simple technique called solvent dispersion, using US Food and Drug Administration (FDA)-approved excipients for drugs. Differential scanning calorimetry (DSC) and dynamic light scattering (DLS) were used to characterize the formulations’ physical properties. Cytotoxicity analysis, cellular antioxidant activity assay, and a pharmacokinetic study were performed to evaluate the biological properties of these two formulations. The final weight ratios of both hesperetin to TPGS and hesperetin to PC were 1:12 based on their water solubility, which increased to 21.5- and 20.7-fold, respectively. The hesperetin-TPGS micelles had a small particle size of 26.19 nm, whereas the hesperetin-PC complexes exhibited a larger particle size of 219.15 nm. In addition, the cellular antioxidant activity assay indicated that both hesperetin-TPGS micelles and hesperetin-PC complexes increased the antioxidant activity of hesperetin to 4.2- and 3.9-fold, respectively. Importantly, the in vivo oral absorption study on rats indicated that the micelles and complexes significantly increased the peak plasma concentration (Cmax) from 2.64 μg/mL to 20.67 and 33.09 μg/mL and also increased the area under the concentration–time curve of hesperetin after oral administration to 16.2- and 18.0-fold, respectively. The micelles and complexes increased the solubility and remarkably improved the in vitro antioxidant activity and in vivo oral absorption of hesperetin, indicating these formulations’ potential applications in drugs and healthcare products.

Preparation and characteristics of TPGS-CS/PTX polymeric micelles and its in vivo intestines absorption in rats / 中草药

Objective To obtain the intestines absorption of TPGS-CS/PTX polymeric micelles in rats, a drug-loaded micelle system was established by a kind of amphiphilic copolymer, D-α-tocopherol polyethylene glycol 1000 succinate-chitosan (TPGS-CS) was prepared by grafting D-α-tocopherol polyethyleneglycol 1000 succinate (TPGS) as the donor of the micelle hydrophobic group on chitosan (CS) as bioadhesive material, and loading paclitaxel as model drug. Methods TPGS was activated by its hydroxy-terminal carboxylation with succinic anhydride (SA) and 4-dimethylaminopyridine (DMAP). The TPGS-CS copolymer was prepared by the amidation of free amino groups on CS. The chemical structure of the TPGS-CS grafted copolymer was characterized by Fourier transform-infrared spectroscopy (FT-IR) and Nuclear magnetic resonance spectroscopy (NMR). The polymer micelle loading paclitaxel was selected as model drug and TPGS-CS/PTX was prepared by ultrasonic emulsification method. The encapsulation efficacy (EE) and drug loading (DL) were determined by high performance liquid chromatography (HPLC). The particle size, Zeta potential, and size distribution of the micelle system were measured by dynamic light scattering (DLS). The surface morphology of the micelles was investigated by Transmission electron microscopy (TEM). The in vivo intestines absorption rate (Ka) of paclitaxel-loaded TPGS-CS micelle was calculated in rats. Results The results of FT-IR and 1H NMR indicated that the copolymer (TPGS-CS) was synthesized. The TEM result showed that the formed particles were uniform in shape without aggregation. The Ka of TPGS-CS/PTX was 20 percent higher in comparison to the reference preparation, it indicated that this polymeric micelles could increase bioavailability. Conclusion The proposed TPGS-CS copolymer was successfully synthesized in this experiment, and the drug-loaded micelles prepared by ultrasonic emulsification exhibited good characteristics compared with the reference preparation, the Ka of paclitaxel was increased to some extent to promote oral absorption of the drug.

Application of TPGS-based nano-drug delivery system in reversing P-gp mediated multidrug resistance / 药学学报

Multidrug resistance (MDR) seriously affects the clinical efficacy of chemotherapeutic drugs. One of the main mechanisms of MDR is the overexpression of P-glycoprotein (P-gp) in tumor cells that reduces the intracellular drug concentrations and limits the effective use of chemotherapeutic drugs. Accordingly, application of P-gp inhibitors that can reverse tumor MDR is an effective strategy to enhance the anti-tumor effect of chemotherapeutic drugs. In recent years, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) has been widely applied as the potential P-gp inhibitor for its excellent P-gp inhibition effect as well as good safety. In this paper, we reviewed the P-gp inhibitors, the mechanisms of TPGS in reversing P-gp-mediated MDR and the application of TPGS-based nano-drug delivery system.

Formulation Screening and in vitro Stability of Quercetin-loaded PLGA-TPGS Nanoparticles / 医药导报

Objective To study the best formulation and technology of quercetin-loaded polylactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate(PLGA-TPGS) nanoparticles(QPTN) with QT as model drug and PLGA-TPGS as polymer materials by orthogonal tests,and to investigate the in vitro stability of QPTN. Methods To ensure the best formula-tion and technology for preparing QPTN,single-factor test was established to determine the influence of the ratio of quercetin to PLGA-TPGS,the concentration of TPGS as emulsifiers,the ultrasonic power and ultrasonic time to the particle size,drug loading (DL) and entrapment efficiency(EE).According to single-factor test,the factor levels of nanoparticles were set to select the best prescription and technology of QPTN by orthogonal test.The stability of QPTN was examined using the effecting factor test,accel-eration test and long-term test. Results The best formulation and technology of QPTN was that the ratio of quercetin to PLGA-TPGS was 3:10 (W:W) with 0.05% TPGS as emulsifier,the mixed solution was sonicated for 6 min at 200 W.The average particle size,DL and EE of QPTN prepared under the conditions described above were (155.4 ± 2.7) nm,(21.6 ± 1.5)% and (93.7±2.9)% (n=6),respectively.In the in vitro stability test,QPTN showed a good stability at high temperature,high humidity and strong light condition. Conclusion The best formulation and preparation technology of QPTN was selected.QPTN got small particle size,high DL and EE,and good in vitro stability.

Preparation of TPGS-modified artesunate liposomes and their in vitro anti-tumor activity / 中成药

AIM To prepare D-α-tocopherol polyethylene glycol 1000 succinate (TPGS)-modified artesunate liposomes and to investigate the in vitro anti-tumor activity.METHODS The liposomes prepared by thin-film dispersion method were characterized by transmission electron microscopy and particle size analyzer,and the encapsulation efficiency was determined by ultrafiltration centrifugation.The liposomes' cytotoxicity to human hepatoma HepG2 cells was evaluated by MTT method.RESULTS The average particle size,PDI,Zeta potential,encapsulation efficiency,drug loading of the liposomes were 126.7 nm,0.182,-10.1 mV,78.8％ and 18.38％,respectively.The liposomes displayed a significant inhibition on HepG2 cells with the IC50 value of 0.034 μmol/mL.CONCLUSION Compared with non-TPGS-modified artesunate liposomes,the TPGS-modified artesunate liposomes prepared by this method afford smaller vesicle size,better stability and higher encapsulation efficiency with stronger in vitro anti-tumor activity.

Preparation and evaluation of GEN-VES-TPGS1000 nano-micelles / 中草药

Objective: To prepare GEN-VES-TPGS nano-micelles and improve the oral bioavailability of genistein (GEN). Methods: GEN-VES-TPGS nano-micelles, made by film hydration, were evaluated with particle size, entrapment efficiency, and drug-loading as indexes. Single factor experiment was used to optimize the formulation and productive technology, including dosages of TPGS, VES, GEN, hydration volume, temperature, and time. Morphology of nano-micelles, release rate in vitro, and pharmacokinetics in rat were investigated. Results: The results showed GEN-VES-TPGS nano-micelles presented with good clarity, appropriate particle diameter (43.50 ± 1.65) nm, negative charge, when the dosages of TPGS, VES, GEN were 200, 30, and 6 mg, respectively. Meanwhile, a condition of 15 mL, 50 ℃ at 3 h to hydrate was necessary to prepare. In this setting, the encapsulation efficiency of the nano-micelles was (98.99 ± 0.69)% and drug-loading rate was (2.57 ± 0.04)%. The pharmacokinetic results in rats showed the oral bioavailability of GEN-VES-TPGS nano-micelles was 162.96% of the GEN APIs. Conclusion: The prepared GEN-VES-TPGS nano-micelles have small particle size and good stability, and increase the oral bioavailability of GEN evidently.

Study on Inhibitory Effects of Sinomenine-loaded PLGA-TPGS Nanoparticles on the Proliferation of HCa-F Cells in Lymph Tubes and Ectopic Transplantation Tumors in Mice / 中国药房

OBJECTIVE:To study the inhibitory effects of sinomenine(SIN)-loaded polylactic-co-glycolic acid-D-α-tocopherol polyethylene glycol 1000 succinate(PLGA-TPGS)nanoparticles(SPTN)on the proliferation of HCa-F cells in lymph tubes and ec-topic transplantation tumors in mice. METHODS:HCa-F cell suspension were incubated with normal saline,5-fluorouracil(FS), sinomenine solutions (SS),sinomenine PLGA nanoparticles (SPN) and SPTN,with concentration of 80 μg/ml. The cells were marked with CFSE,and then were injected with suspension 50 μl via one footpad of mice. Inhibitory effect of above suspensions on the proliferation of HCa-F in lymph tubes of mice was observed by fluorescence inverted microscope at 3,6,9,12,24 h(n=15). Mice were divided into normal control group,blank PLGA-TPGS nanoparticles (EPTN) group,normal saline group,SPTN group,SPN group,SS group and FS group with 10 mice in each group. The latter 5 groups were injected with relevant medicine 15 mg/kg,once a day,via tail vein for consecutive 10 days after the model of HCa-F cells-bearing ectopic transplantation tumor mice was established. The serum content of ALT,AST,γ-glutamyltransferase(γ-GT),ALB and T-BIL were determined;solid tu-mors were taken,measured and weighed,and the inhibitory rate of tumor was also calculated. RESULTS:The inhibitory effect of above solution on the proliferation of HCa-F cells in descending order was as follows:SPTN>SPN>FS>SS>normal saline. Com-pared with normal saline group,the serum levels of ALT,AST,γ-GT and TBIL of SPTN group,SPN group,SS group and FS group decreased,while ALB level increased(P<0.05);the amount of tumor volume increase and tumor weight in SPTN group, SPN group and FS group decreased significantly (P<0.05). The inhibitory rate of tumor in 3 groups were 49.62%,40.53% and 33.90%. CONCLUSIONS:SPTN can inhibit the proliferation of HCa-F cells in lymph tubes of mice,and can improve HCa-F cells-bearing ectopic transplantation tumor in mice. It is better than SPN and FS.

Effect of D-α-tocopherol polyethylene glycol 1000 succinate on inhibition of MCF-7 cell proliferation by baohuoside I / 中草药

Objective: To investigate the effect of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) on the inhibition of proliferation of breast cancer cells MCF-7 by baohuoside I. Methods: The cytotoxicity of baohuoside I to MCF-7 cells was determined by MTT assay, the cellular uptake of baohuoside I was detected by fluorescence microscopy, and the intracellular baohuoside I was determined by HPLC. Results: The effect of baohuoside I on the inhibition of MCF-7 cell proliferation was enhanced in the presence of TPGS, especially on lower concentration. The uptake rates of MCF-7 within 2 h were 29.51%, 38.12%, and 40.37%, when the proportions of baohuosaide I and TPGS were 1:1, 1:2, and 1:4, respectively. The ratios were increased by 27.92%, 65.24%, and 74.99% compared with those using baohuoside I only. Conclusion: TPGS can increase the uptake rate of baohuoside I in MCF-7 cells and enhance the inhibition of MCF-7 cell proliferation.

Preparation of colchicine ethosomes containing TPGS and in vitro transdermal permeation / 中草药

Objective: To prepare and optimize the prescription of colchicine ethosomes containing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and to investigate its feasibility as a carrier for transdermal drug delivery. Methods: The colchicine ethosomes containing TPGS were prepared by the injection-sonication method. And the encapsulation efficiency (EE) was determined by minicolumn centrifugation method. The prescription of ethosomes was optimized by uniform design with EE as the evaluation index, and the physicochemical properties of the optimized ethosomes were investigated. Characterization of the vesicles was based on particle size, Zeta potential, entrapment efficiency, and transmission electron microscopy (TEM). The transdermal permeation characteristics of ethosomes, colchicine 30% ethanol solution, and colchicine ethosomes containing TPGS were compared by using Franz diffusion cells. Results: The optimized formulation was as follows: The contents of soybean phospholipid and TPGS were 350 and 50 mg, respectively. In addition, the concentration of ethanol was 36.44%. The average EE, particle size, polydispersity index, and Zeta potential were (74.71 ± 2.18)%, (89.6 ± 3.5) nm, 0.201 ± 0.008, and (-34.6 ± 2.7) mV, respectively. The in vitro experiment showed that the transdermal flux, permeation rate, and skin deposition of colchicine ethosomes were (64.49 ± 5.61) μg/cm2, (2.84 ± 0.23) μg/(cm2∙h), (128.22 ± 11.64) μg/cm2, and the transdermal flux, permeation rate, and skin deposition of colchicine ethosomes containing TPGS were (91.36 ± 7.11) μg/cm2, (4.73 ± 0.38) μg/(cm2∙h), and (182.84 ± 14.37) μg/cm2, respectively, which was significantly higher than those in ethosomes. Conclusion: The colchicine ethosomes containing TPGS show high EE and obviously enhance the percutaneous absorption of colchicine, which might be a potential carrier for transdermal drug delivery.

Study on Pharmacokinetics of Capecitabine/Polyethylene Glycol 1000/Montmorillonite Compound in Rats in vivo / 中国药房

OBJECTIVE:To establish a method of determining the plasma concentration of capecitabine/polyethylene glycol 1000/montmorillonite (CAP/PEG1000/MMT) in rats’plasma for the study on pharmacokinetics of CAP compound in rats in vivo. METHODS:HPLC was adopted. The determination was performed on Kromasil C18 with mobile phase consisted of 0.1% glacial acetic acid-acetonitrile(73∶27),at the flow rate of 1.0 ml/min. The detection wavelength was 250 nm and column temperature was 40 ℃. The sample size was 10 μl. 18 Wistar rats were randomly divided into CAP group,CAP/MMT group(MMT as carrier)and CAP/PEG1000/MMT group(PEG1000/MMT as carrier)and ig given corresponding drugs,that equal to 200 mg/kg of CAP. Blood sample was respectively taken 15,30,60,90,120,180,240,300 and 360 min after the administration of drugs,and plasma was isolated and added with internal standard ferulic acid. The concentration of the drug in the plasma was determined by HPLC fol-lowing protein precipitation with methanol,based on which the pharmacokinetic parameters were calculated by 3p97 software. RE-SULTS:The linear range of CAP was 0.054 9-4.390 0 μg/ml (r=0.998 2) with the method recovery of 98.2%-102.1%(RSD=1.50%-3.29%, n=5) and absolute recovery of 76.2%-78.9%(RSD=2.29%-2.99%, n=5). In the above-mentioned three groups,t1/2 were(1.11±0.32),(1.57±0.32)and(1.62±0.10)h;cmax were(2.91±0.36),(0.91±0.23)and(0.91±0.14)μg/ml;AUC0-6 h were (8.70 ± 1.79),(3.76 ± 0.27) and (3.73 ± 0.25)μg·h/ml;and tmax were (0.97 ± 0.20),(1.55 ± 0.47) and (1.50 ± 0.07) h,respectively. There was no significant difference in the pharmacokinetic parameters between the CAP/MMT group and CAP/PEG1000/MMT group(P>0.05). CONCLUSIONS:The method is reliable and simple,and can be used for pharmacokinetic study of CAP/PEG1000/MMT in rats. MMT and PEG1000/MMT compound can prolong CAP acting time in the body.

Preparation of paclitaxel-loaded mixed micelles and its in situ absorption in rat intestine / 中国药学杂志

OBJECTIVE: To study the oral absorption of paclitaxel-loaded mixed micelles made of D-α-tocopherol polyethylene glycol 1000 succinate(TPGS) and sodium cholate(NaC) in rats. METHODS: Paclitaxel-loaded mixed micelles were prepared by film dispersion method. The Zeta potential and diameter distribution of TPGS/NaC mixed micelles were measured using laser size scattering determinator. The morphology of micelles was observed by transmission electron microscope. Dialysis method was used to evaluate the release behavior of drug-loaded micelles in vitro. The absorption kinetics was obtained by in situ perfusion method in rats. RESULTS: Most of the mixed micelles were spherical with an average diameter of 24.2 nm and the Zeta potential was -7.84 mV. Compared to the bulk drug, the apparent absorption rate constant (Ka)of paclitaxel-loaded mixed micelles was increased significantly. CONCLUSION: TPGS/NaC mixed micelles can improve the oral absorption of paclitaxel and increase its oral bioavailability.