Chunnuan Wu

Stealth CD44-targeted hyaluronic acid supramolecular nanoassemblies for doxorubicin delivery: probing the effect of uncovalent pegylation degree on cellular uptake and blood long circulation.

Stealth active targeting nanoparticles (NPs) usually include two types of ligand sites: ligand anchored on distal ends of the polyethylene glycol (PEG) and ligand buried under pegylated layer. The latter typical case is hyaluronic acid (HA)-based NPs; however, there is little information available for the latter NPs about effect of the optimal density of surface PEG coating on the blood circulation time, cellular uptake and in vivo anticancer activity. Thus, in this study, in order to optimize the anticancer effects of HA-based NPs, we focus on how uncovalent pegylation degree modulates blood circulation time and cellular uptake of HA-based NPs. We firstly designed a new double-hydrophilic copolymer by conjugating HP-β-cyclodextrin with HA, and this carrier was further pegylated with adamantyl-peg (ADA-PEG) to form inclusion complex HA-HPCD/ADA-PEG, termed as HCPs. The supramolecular nanoassemblies were fabricated by host-guest and polar interactions between HCPs and doxorubicin (Dox), with vitamin E succinate (VES) being a nanobridge. Despite the active recognition between HA and CD44 receptor, the cellular uptake and targeting efficiency of HA-NPs decreased with the increasing peg density, demonstrating HA was partly buried by high density peg coating. However, the high density of peg coating was beneficial to long circulation time, tumor biodistribution and anticancer activity in vivo. NPs with 5% peg coating had the optimal cellular targeting efficiency in vitro and anticancer effects in vivo. The findings suggest that balancing long circulation property and cellular uptake is important to achieve the optimal antitumor efficacy for pegylated HA-based NPs, and that PEG coating densities cannot be extended beyond a certain density for shielding effect without compromising the efficacy of hyaluronic acid targeted delivery.

Enhanced Oral Delivery of Paclitaxel Using Acetylcysteine Functionalized Chitosan-Vitamin E Succinate Nanomicelles Based on a Mucus Bioadhesion and Penetration Mechanism

In addition to being a physiological protective barrier, the gastrointestinal mucosal membrane is also a primary obstacle that hinders the oral absorption of many therapeutic compounds, especially drugs with a poor permeability. In order to resolve this impasse, we have designed multifunctional nanomicelles based on the acetylcysteine functionalized chitosan-vitamin E succinate copolymer (CS-VES-NAC, CVN), which exhibit marked bioadhesion, possess the ability to penetrate mucus, and enhance the oral absorption of a hydrophobic drug with a poor penetrative profile, paclitaxel. The intestinal absorption (Ka = 0.38 ± 0.04 min(-1), Papp = 0.059 cm · min(-1)) of CVN nanomicelles was greatly improved (4.5-fold) in comparison with paclitaxel solution, and CLSM (confocal laser scanning microscope) pictures also showed not only enhanced adhesion to the intestinal surface but improved accumulation within intestinal villi. The in vivo pharmacokinetics indicated that the AUC0-t (586.37 ng/mL · h) of CVN nanomicelles was markedly enhanced compared with PTX solution. In summary, the novel multifunctional CVN nanomicelles appear to be a promising nanocarrier for insoluble and poorly permeable drugs due to their high bioadhesion and permeation-enhancing capability.

Protective effects of pseudoginsenoside-F11 on scopolamine-induced memory impairment in mice and rats

This study assessed the effects of pseudoginsenoside‐F11, a component of Panax quinquefolium L., on scopolamine‐impaired memory performance in mice and rats.

Rod shaped nanocrystals exhibit superior in vitro dissolution and in vivo bioavailability over spherical like nanocrystals: a case study of lovastatin.

The objective of this study was to compare the in vitro and in vivo performance of rod shaped and spherical like nanocrystals for oral administration. Lovastatin (LOV) was chosen as the model drug and LOV rod shaped nanocrystals (LOV-RNs) and spherical like nanocrystals (LOV-SNs) were prepared by sonoprecipitation and bead milling, respectively. The dry powders obtained following freeze-drying were characterized by hydrodynamic diameter, polydispersity index, zeta potential, transmission electron microscope, scanning electron microscope, atomic force microscope, differential scanning calorimetry, Fourier transform infrared spectroscopy, and in vitro dissolution test. The pharmacokinetic study was performed in beagle dogs. The results obtained showed that LOV-RNs and LOV-SNs had similar hydrodynamic diameters (500.6±21.0 nm versus 503.2±20.4 nm), and the same crystalline state. The dissolution test showed that LOV-RNs had a higher dissolution rate than LOV-SNs. The AUC(0-24h) values of LOV-RNs and LOV-SNs were higher than Junning® for both LOV (p<0.05 for LOV-RNs, and p>0.05 for LOV-SNs) and lovastatin acid (p>0.05). More importantly, the oral bioavailability of LOV-RNs was higher than LOV-SNs (p>0.05). The findings of this study show that the crystal shape has a significant effect on oral bioavailability.

Star‐Shape Redox‐Responsive PEG‐Sheddable Copolymer of Disulfide‐Linked Polyethylene Glycol‐Lysine‐di‐Tocopherol Succinate for Tumor‐Triggering Intracellular Doxorubicin Rapid Release: Head‐to‐Head Comparison

A redox-responsive poly(ethylene glycol) (PEG)-sheddable copolymer of disulfide-linked PEG 5000-lysine-di-tocopherol succinate (P(5k)SSLV) is developed which can self-assemble into nanomicelles in aqueous condition and trigger the rapid release of encapsulated drugs within tumor cells. The reduction-insensitive doxorubicin (DOX)-loaded P(5k)LV (P(5k)LV-DOX) nanomicelles are further prepared. Then head-to-head comparison of P(5k)SSLV-DOX, P(5k)LV-DOX and DOX-Sol is performed concerning in vitro release, cytotoxicity, cellular uptake and apoptosis. Results show that P(5k)SSLV-DOX nanomicelles have a faster DOX release, a higher anti-tumor activity and more DOX concentrating in the nucleus than P(5k)LV-DOX nanomicelles. In conclusion, the redox-responsive P(5k)SSLV nanomicelles might hold a great potential to improve chemotherapy by tumor-triggering intracellular rapid release. The outcomes of this study also address the significance of such head-to-head comparison studies in translational research of nanomedicine.

Interspecies prediction of oral pharmacokinetics of different lacidipine formulations from dogs to human: physiologically based pharmacokinetic modelling combined with biorelevant dissolution

The aim of the present study was to use physiologically based pharmacokinetic (PBPK) modelling combined with biorelevant dissolution to quantitatively predict dog oral drug pharmacokinetic (PK) of different formulations, and to make an interspecies extrapolation to human. Lacidipine, a typical BCS class II drug, was chosen as a model drug. The three lacidipine formulations involved were immediate release tablets including two commercial products and one self-made micronized tablets. First of all, the PBPK models in rat and dog after intravenous administration of lacidipine solutions and oral administration of lacidipine suspensions were developed and validated based on physicochemical properties and the literature data, which were used to verify the accuracy of the PBPK model in prediction drug PK in animals. The solubility and dissolution behaviour of lacidipine formulations were determined in the media simulating the fasted state intestinal fluid of human (FaSSIF/FaSSIF-V2). Then the Z-factor values obtained by fitting the dissolution profiles of the three formulations were utilized to evaluate the effect of in vitro dissolution behaviours on PK performance. At last, the verified PBPK model in dog was extrapolated to predict human PK of the three formulations. The results showed that PBPK models from dog to human were successfully developed. By integrating biorelevant dissolution with PBPK model, it is achievable to quantitatively and accurately predict the plasma concentration–time profiles for various formulations after oral administration.

Profiling biopharmaceutical deciding properties of absorption of lansoprazole enteric-coated tablets using gastrointestinal simulation technology.

The aim of the present study was to correlate in vitro properties of drug formulation to its in vivo performance, and to elucidate the deciding properties of oral absorption. Gastrointestinal simulation technology (GST) was used to simulate the in vivo plasma concentration-time curve and was implemented by GastroPlus™ software. Lansoprazole, a typical BCS class II drug, was chosen as a model drug. Firstly, physicochemical and pharmacokinetic parameters of lansoprazole were determined or collected from literature to construct the model. Validation of the developed model was performed by comparison of the predicted and the experimental plasma concentration data. We found that the predicted curve was in a good agreement with the experimental data. Then, parameter sensitivity analysis (PSA) was performed to find the key parameters of oral absorption. The absorption was particularly sensitive to dose, solubility and particle size for lansoprazole enteric-coated tablets. With a single dose of 30 mg and the solubility of 0.04 mg/ml, the absorption was complete. A good absorption could be achieved with lansoprazole particle radius down to about 25 μm. In summary, GST is a useful tool for profiling biopharmaceutical deciding properties of absorption of lansoprazole enteric-coated tablets and guiding the formulation optimization.

A rapid and sensitive LC-MS/MS method for evaluation of the absolute oral bioavailability of a novel c-Met tyrosine kinase inhibitor QBH-196 in rats.

A sensitive, selective and high-throughput UPLC-MS/MS method was developed and validated for the determination of a novel c-Met tyrosine kinase inhibitor, QBH-196, in rat plasma. QBH-196 and its analog BH357 (IS) were extracted from rat plasma using a mixture of dichloromethane and N-hexane (2:3, v/v). The chromatographic separation was carried out on Phenomenex C18 column (50 × 2.1 mm, 2.6 µm particle size) with a gradient mobile phase of methanol (A) and water containing 0.05% formic acid (B) at a flow rate of 0.2 mL/min. The assay was performed by positive electrospray ionization in multiple reaction monitoring mode using transitions of m/z 622.68 → 140.41 for QBH-196 and m/z 591.19 →126.21 for the IS, respectively. Good linearity was obtained over the concentration range of 8.0-4000 ng/mL (r(2) > 0.99) for QBH-196 and the lower limit of quantification was 8.0 ng/mL in rat plasma. Validations of the method, including its sensitivity, extraction recovery, matrix effect, intra- and inter-day precision, accuracy and stability, were all within acceptable limits. The established method was successfully applied to determine absolute oral bioavailability of QBH-196 in rats for the first time. The mean oral absolute bioavailability of QBH-196 was found to be about 40.8% and the elimination half-life was 40.0 ± 13.1 h. This result suggested that QBH-196 exhibits good oral absorption in vivo, which is very important for the further development of QBH-196 as a new oral anticancer drug.

Determination of Doxorubicin in Stealth Hyalurionic Acid-Based Nanoparticles in Rat Plasma by the Liquid–Liquid Nanoparticles-Breaking Extraction Method: Application to a Pharmacokinetic Study

An efficient extraction of doxorubicin (Dox) from homemade stealth hyalurionic acid (HA)-based nanoparticles (NPs) in rat plasma could not be performed by previously published methods. Therefore, we attempted to establish the novel NPs-breaking and UPLC-MS-MS method for evaluating the pharmacokinetic profiles of the homemade stealth HA NPs in rats. The pretreatment method of plasma samples used the liquid-liquid extraction method with isopropyl alcohol as NPs-breaking and protein-precipitating solvents, and the NPs-breaking efficiency of isopropyl alcohol was as high as 97.2%. The analyte and gliclazide (internal standard) were extracted from plasma samples with isopropyl alcohol and were separated on UPLC BEH C18 with a mobile phase consisting of methanol and water (containing 0.1% formic acid). The method demonstrated good linearity at the concentrations ranging from 5 to 5,000 ng/mL. The intra- and interday relative standard deviations were >10%. Finally, the method was successfully applied to a pharmacokinetic study of homemade stealth HA-based NPs in rats following intravenous administration.