Preparation of Tetrandrine Nanocrystals by Microfluidic Method and Its In Vitro and In Vivo Evaluation.

The anti-hepatocellular carcinoma effects of TET are acknowledged, but its application is hindered by its poor water solubility and low bioavailability. Conventional methods for nanocrystal preparation are laborious and lack control. To address these limitations, we propose employing the microfluidic method in the preparation of TET nanocrystals, aiming to enhance the aforementioned constraints. The objectives of this study were to prepare TET nanocrystals (TET-NC@GL) using a Y-microfluidic method with glycyrrhetinic acid (GL) as a stabilizer. The optimal preparation prescription was determined through a single-factor test and Box-Behnken response surface method. Additionally, the nanocrystals prepared with the commonly used stabilizer polyvinylpyrrolidone K30 (PVPK30), known as TET-NC@PVPK30, were characterized and evaluated for their toxicity to HepG2 cells. Hybridized nanocrystals (TET-HNC@GL and TET-HNC@PVPK30) were synthesized using a water-soluble aggregation-induced emission (AIE) fluorescent probe (TVP). Qualitative and quantitative cellular uptake experiments were conducted using these hybridized nanocrystals. Conducting in vivo pharmacokinetic assays evaluates the relative bioavailability of nanocrystals. The results indicated that TET-NC@GL, optimized using the response surface method, had a particle size of 136.47 ± 3.31 nm and a PDI of 0.219 ± 0.002. The administration of TET-NC@GL significantly enhanced the cell inhibition rate compared to the TET group and the TET-NC@PVPK30 group (P < 0.01). Moreover, the qualitative and quantitative cellular uptake results revealed a significant enhancement in cellular uptake in the TET-HNC@GL administration group compared to the TET-HNC@PVPK30 group (P < 0.01). In vivo pharmacokinetic results showed that the bioavailability of TET-NC@GL group was 3.5 times higher than that of the TET group. The results demonstrate the successful preparation of TET-NC@GL nanocrystals.

[Pharmacokinetics and bioavailability of ginsenoside Rg1 in rats].

OBJECTIVE: To investigate the pharmacokinetics and bioavailability of ginsenoside Rg1 in rats. METHODS: Ginsenoside Rg1 was oral administered or intravenous administered to each rat. The plasma concentration of ginsenoside Rg1 was estimated by RP-HPLC. 3P97 software was used to calculate pharmacokinetic parameters. RESULTS: Main parameters of ginsenoside Rg1 after oral or intravenous administered were: AUC(0 --> t), 322.70 +/- 20.78, 99.76 +/- 8.91 microg x h/mL, CL 0.08 +/- 0.02, 3.01 +/- 0.69 L/(kg x h), V 0.23 +/- 0.01, 22.75 +/- 2.09 L/kg, t1/2alpha 0.48 +/- 0.18, 0.87 +/- 0.21 h, t1/2beta 19.57 +/- 2.81, 18.68 +/- 2.74 h, MRT6.91 +/- 0.99, 8.15 +/- 1.05 h(-1), respectively. The relative oral bioavailability of ginsenoside Rg1 was 2.5%. CONCLUSION: The oral bioavailability of ginsenoside Rg1 is very low.

A polymeric nanocarrier that eradicates breast cancer stem cells and delivers chemotherapeutic drugs.

BACKGROUND: Drug nanocarriers can markedly reduce the toxicities and side effects of encapsulated chemotherapeutic drugs in the clinic. However, these drug nanocarriers have little effect on eradicating breast cancer stem cells (BCSCs). Although compounds that can inhibit BCSCs have been reported, these compounds are difficult to use as carriers for the widespread delivery of conventional chemotherapeutic drugs. METHODS: Herein, we synthesize a polymeric nanocarrier, hyaluronic acid-block-poly (curcumin-dithiodipropionic acid) (HA-b-PCDA), and explore the use of HA-b-PCDA to simultaneously deliver chemotherapeutic drugs and eradicate BCSCs. RESULTS: Based on molecular docking and molecular dynamics studies, HA-b-PCDA delivers 35 clinical chemotherapeutic drugs. To further verify the drug deliver ability of HA-b-PCDA, doxorubicin, paclitaxel, docetaxel, gemcitabine and camptothecin are employed as model drugs to prepare nanoparticles. These drug-loaded HA-b-PCDA nanoparticles significantly inhibit the proliferation and stemness of BCSC-enriched 4T1 mammospheres. Moreover, doxorubicin-loaded HA-b-PCDA nanoparticles efficiently inhibit tumor growth and eradicate approximately 95% of BCSCs fraction in vivo. Finally, HA-b-PCDA eradicates BCSCs by activating Hippo and inhibiting the JAK2/STAT3 pathway. CONCLUSION: HA-b-PCDA is a polymeric nanocarrier that eradicates BCSCs and potentially delivers numerous clinical chemotherapeutic drugs.

Transmission network and phylogenetic analysis reveal older male-centered transmission of CRF01_AE and CRF07_BC in Guangxi, China.

In China, the number of newly reported HIV infections in older people is increasing rapidly. However, clear information on the impact of older people on HIV transmission is limited. This study aims to reveal the local HIV transmission patterns, especially how older people affect virus transmission. Subtype analysis based on available pol sequences obtained from HIV patients revealed that CRF01_AE and CRF08_BC were predominant in patients aged <50 years, whereas CRF01_AE was predominant in older people aged ≥50 years (χ2 = 29.299, P < 0.001). A total of 25 patients (5.2%, 25/484) were identified with recent HIV infection (RHI). Transmission network analysis found 267 genetically linked individuals forming 55 clusters (2-63 individuals), including 5 large transmission clusters and 12 transmission clusters containing RHI. Bayesian phylogenetic analysis suggested that transmission events in CRF01_AE and CRF07_BC were centred on older males, while transmission events in CRF08_BC were centred on younger males. Multivariable logistic regression analysis showed that older people were more likely to cluster within networks (AOR = 2.303, 95% CI: 1.012-5.241) and that RHI was a significant factor associated with high linkage (AOR = 3.468, 95% CI: 1.315-9.146). This study provides molecular evidence that older males play a central role in the local transmission of CRF01_AE and CRF07_BC in Guangxi. Given the current widespread of CRF01_AE and CRF07_BC in Guangxi, there is a need to recommend HIV screening as part of free national medical examinations for older people to improve early detection, timely treatment, and further reduce second-generation transmission.

Self-Nanoemulsifying Drug Delivery System of Tetrandrine for Improved Bioavailability: Physicochemical Characterization and Pharmacokinetic Study.

The main purpose of this study was to investigate the potential of self-nanoemulsified drug delivery system (SNEDDS) to improve the oral bioavailability of tetrandrine (Tet). SNEDDS was developed by using rational blends of excipients with good solubilizing ability for Tet which was selected based on solubility studies. Further ternary phase diagram was constructed to determine the self-emulsifying region. The optimal formulation with the best self-nanoemulsified and solubilization ability consisted of 40% (w/w) oleic acid as oil, 15% (w/w) SPC and 30% (w/w) Cremophor RH-40 as surfactant, and 15% (w/w) PEG400 as cosurfactant. The average droplet size and zeta-potential of the optimal Tet SNEDDS were 19.75±0.37 nm and 1.87±0.26 mv, respectively. The dissolute rate of Tet SNEDDS in various dissolution media was remarkably faster than Tet commercial tablet. Moreover, in vivo pharmacokinetic study results show that significant increase (p≤ 0.05) in the peak concentration (Cmax) and the area under the curve (AUC) of Tet was observed after the oral administration of Tet SNEDDS and the absorption of Tet from SNEDDS resulted in approximately 2.33-fold increase in oral bioavailability compared with the commercial tablet. Our research suggests that the prepared Tet SNEDDS could be a good candidate for improved the dissolution and oral bioavailability of Tet.

Pharmacokinetics of Quercetin-Loaded Methoxy Poly(ethylene glycol)-b-poly(L-lactic acid) Micelle after Oral Administration in Rats.

The purpose of this study was to evaluate the potential of micelle to change the pharmacokinetics of quercetin (QUT), with a primary goal of enhancing its oral bioavailability. QUT-loaded methoxy poly(ethylene glycol)-b-poly(L-lactic acid) micelle (QUT-loaded MPEG-b-PLLA micelle) was prepared by a thin-film hydration method, resulting in a particle size of 88.5 nm. A liquid chromatography tandem-mass spectrometry (LC-MS/MS) method was developed and validated for determination of QUT in rat plasma. The chromatographic separation was performed on an Agilent Eclipse-C18 (4.6 mm × 50 mm, 3.5 µm) with an isocratic mobile phase system consisting of water and methanol (30 : 70, v/v) at a flow rate of 0.4 mL/min. Calibration curves were linear over the concentration ranges of 2.5-2000 ng/mL for QUT. The micelle was orally administered at a single does in rats, and the pharmacokinetic parameters were evaluated and compared with that administered with the QUT aqueous suspension. The results show that the micelle was able to increase the QUT's oral bioavailability 9-fold compared to the QUT aqueous suspension. These results suggest that methoxy poly(ethylene glycol)-b-poly(L-lactic acid) is a potential carrier for the oral delivery of QUT.

Simultaneous determination of L-dopa and its prodrug (S)-4-(2-acetamido-3-ethoxy-3-oxopropyl)-1,2-phenylene diacetate in rat plasma by high-performance liquid chromatography-tandem mass spectrometry and its application in a pharmacokinetic study.

A sensitive, simple and rapid HPLC-MS/MS method has been developed and validated for the simultaneous determination of L-dopa and its prodrug (S)-4-(2-acetamido-3-ethoxy-3-oxopropyl)-1,2-phenylene diacetate (AEPD) in rat plasma in the present study. The analytes were separated on a C(18) column (5 microm, 2.1 mm x 150 mm) with a security guard C(18) column (5 microm, 4 mm x 20 mm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was applied for detection. With alpha-methyldopa as internal standard, sample pretreatment involved in a one-step protein precipitation with 0.4M perchloric acid. The method was linear over the concentration ranges of 50-5000 ng/ml for L-dopa and 12.5-2500 ng/ml for AEPD. The intra-day and inter-day relative standard deviations (RSD) were less than 15% and the relative errors (RE) were all within 15%. Finally, the method was successfully applied to support the pharmacokinetic study after L-dopa and its prodrug AEPD were orally administrated to the Sprague-Dawley rats, respectively.