[Pharmacokinetics and brain distribution of NMD/TMP-nanoparticles].

This study aims to prepare nimodipine/tetramethylpyrazine-loaded poly(D, L-lactide-co-glycolide) dual-drug nanoparticles (NMD/TMP-NPs) and investigate pharmacokinetics and brain distribution to evaluate the possibility of enhancing the drug effect of dual-drug nanoparticles. NMD/TMP-NPs were prepared via W/O/W emulsion solvent evaporation. Entrapment efficiency and drug loading of NMD/TMP-NPs were investigated by ultracentrifugation, and drug release behavior in vitro was studied by dialysis method. The pharmacokinetic and brain distribution were studied in SD mice administered intravenously with NMD/TMP-NPs in comparison with NMD-suspension, NMD/TMP-suspension and NMD-NPs, (NMD-NPs+TMP)-suspension. According to the results, the entrapment efficiency and drug loading of NMD were (79.71±0.73)%, (1.74±0.02)%, those of TMP were (40.26±1.51)% and (4.38±0.16)%. The nanoparticles showed the property of sustained release. On the basis of the major parameters for in vivo pharmacokinetic and brain distribution, t1/2ß of NMD-suspension, NMD/TMP-suspension and NMD-NPs, (NMD-NPs+TMP)-suspension, NMD/TMP-NPs were (1.097±0.146), (1.055±0.06), (1.950±0.140), (1.860±0.096), (2.497±0.475） h, CL were (0.778±0.098), (1.133±0.111), (0.247±0.023), (0.497±0.040), (0.297±0.024) h•L-1, AUC0-t in rat plasma were (514.218±60.383), (352.916±33.691), (1 618.429±240.198), (804.110±75.804), (1 349.058±215.497) µg•h•L⁻¹, respectively, and AUC0-t in brain were 0.301 9, 0.624 8, 1.068 6, 1.313 0, 1.046 5 mg•h•L⁻¹, respectively. According to the in vivo study, the pharmacokinetic behavior of NMD were markedly prolonged by adding TMP or prepared dual-drug nanoparticles.

Bioequivalence Study of Miglitol Orally Disintegrating Tablets in Healthy Chinese Volunteers Under Fasting Condition Based on Pharmacodynamic and Pharmacokinetic Parameters.

To investigate the bioequivalence of miglitol orally disintegrating tablets in healthy Chinese volunteers based on pharmacodynamic (PD) and pharmacokinetic (PK) parameters. Additionally, the safety profile was estimated. Two randomized, open-label, single-dose, crossover trials were conducted under fasting conditions. In the PD trial (CTR20191811), 45 healthy volunteers were randomly divided into 3 groups in a 1:1:1 ratio and administered sucrose alone or coadministered with 50 mg of miglitol orally disintegrating tablet test or reference formulation/sucrose. In the PK trial (CTR20191696), 24 healthy volunteers were randomized (1:1) to receive the test or reference formulation (50 mg). Blood samples were collected at 15 and 17 sampling points per cycle in the PD and PK trials, respectively. Plasma miglitol and serum glucose concentrations were analyzed using a validated liquid chromatography-tandem mass spectrometry method. Serum insulin concentrations were measured using electrochemiluminescent immunoassay. Statistical analyses for the PD and PK parameters were subsequently performed. The volunteers' physical indicators were monitored and documented during the entire study to estimate drug safety. The PD and PK parameters of the two formulations were similar. The main PD and PK end points were both within the prespecified range of 80%-125%. The incidences of treatment-emergent adverse events (TEAEs) and drug-related TEAEs were similar between the test and reference formulation groups, and no serious TEAEs or deaths occurred during the 2 trials. These 2 formulations were demonstrated to be bioequivalent and well tolerated in healthy Chinese volunteers under fasting condition.

[Effects of Mycobacterium tuberculosis on apoptosis of mouse dendritic cells and activation of caspase-3, caspase-8].

OBJECTIVE: To investigate the effects of Mycobacterium tuberculosis on apoptosis of mouse dendritic cells (DC 2. 4) and the activation of caspase-3, caspase-8. METHODS: Mycobacterium tuberculosis H37Rv strain was co-cultured with DC 2. 4 cells. The morphological changes of DC 2. 4 cells were observed with fluorescence microscope after DAPI staining and transmission electron microscope. The apoptosis of DC 2. 4 cells were examined by DNA agarose gel electrophoresis. The activities of caspase-3 and caspase-8 were detected by colorimetric assay. RESULTS: Bacterial invasion was observed while DC 2. 4 cells and H37Rv were co-cultured for 2 h; and the rates of invasion were (16.1 ± 4.3)%, (35.8 ± 5.1)%, (50.2 ± 5.7)%, (58.3 ± 6.2)% and(65.9 ± 6.9)% at 4, 6, 8,10, 12 h, respectively. The phenomenon of nuclear condensation and marginalization were shown by DAPI staining and transmission electron microscope in DC 2. 4 cells at 6 h of co-cultivation with H37Rv. The characteristic bands of apoptosis by DNA electrophoresis were detected. The activities of caspase-3 and caspase-8 were increased in a time-dependent manner. The rates of DC 2. 4 cell apoptosis were (6.4 ± 2.5)%, (11.8 ± 5.3)% and (31.1 ± 8.7)% at 6 h,12 h and 24 h after co-cultivation with H37Rv, respectively. The maximal activities of intracellular caspase-3 and caspase-8 at 10 h and 6 h were (2.01 ± 0.09) U/µg and (2.40 ± 0.07)U/µg, respectively, which was significantly different compared with the control groups(P<0.05). The activation of caspase-8 was earlier than that of caspase-3. CONCLUSION: Mycobacterium tuberculosis can induce the apoptosis of DC 2. 4 cells, which is associated with the activation of intracellular caspase-3 and caspase-8.

[Expression of (His)(6)-eIF3s4 fusion protein in human breast cancer cell Bcap37].

AIM: To construct eukaryotic expression vector of eukaryotic translation initiation factor 3 subunit 4(eIF3s4) for further functional study. METHODS: The cDNA of eIF3s4 containing full length coding region was amplified by RT-PCR and cloned into pGEM-T Easy. The sequence of the cDNA was verified by DNA sequencing and blast against sequence data in GenBank database. The cDNA was then subcloned into the pcDNA4/HisMaxB to make a (His)(6)-eIF3s4 fusion protein expression vector. The vector was transfected into human breast cancer cell Bcap37 by Lipofectamine 2000, and the expression of (His)(6)-eIF3s4 fusion protein was detected by Western blot. RESULTS: DNA sequencing and sequence blast showed that the cDNA amplified by RT-PCR was consistent with the eIF3s4 sequence in GenBank database, and Western blot results showed the expression of the (His)(6)-eIF3s4 fusion protein in human breast cancer cell Bcap37 as expected. CONCLUSION: The (His)(6)-eIF3s4 fusion protein expression vector is constructed successfully with expression of the fusion protein in Bcap37 breast cancer cells. This work provides the basis for establishing a stable eIF3s4 expressing cell line for further study on the role of eIF3s4 in cancer multidrug resistance.