Research progress in cellular pharmacokinetics of nano-drug delivery systems / 药学学报

Nano-drug delivery systems (nano-DDS) are the hotspots of new drug delivery systems, which have many advantages, such as sustained and controlled release, targeting delivery. Traditional pharmacokinetics are difficult to predict the efficacy of drugs in vivo sometimes. It is urgently needed to extend the traditional pharmacokinetics studies to the cell/subcellular level and perform cell pharmacokinetic studies. The study on the pharmacokinetics of nano-DDS helps us to elucidate the mechanism of the actions of them in cells and guides us to design and develop nano-DDS more reasonably. This article summarizes the research content and methods on the cellular pharmacokinetics of nano-DDS, in order to provide an important reference for the early stage design of nano-DDS.

A UPLC-MS/MS method for quantification of a novel doxorubicin conjugation prodrug in tumor cells / 药学学报

In this study, we developed a rapid and sensitive ultra high-performance liquid chromatographytandem mass spectrometry (UPLC-MS/MS) method to detect a sulfide bond doxorubicin conjugation prodrug (DOX-S-DOX) in human breast cancer tumor cells (MCF-7). The samples were prepared by acetonitrile precipitation using daunorubicin as internal standard (IS). A reversed phase C18 analytical column (Agilent Eclipse plus C18 RRHD 1.8 μm, 2.1 mm×50 mm) was utilized to separate the samples under gradient elution conditions. Mobile phase was a mixture of 0.1% formic acid in water and methanol at a flow rate of 0.4 mL ·min-1. The analysis was conducted on the mass spectrometer using an electrospray interface (ESI) in the positive ionization model. The calibration range was 20.0-400 ng·mL-1 with the correlation coefficients (r2) ≥ 0.99. The inter-and intra-assay precision (relative standard deviation, RSD%) of quality control samples was within 3.77%-8.35% and relative error (RE%) for accuracy was between -2.04% and 2.62%. Recovery (97.67%-104.2%) and matrix effect (104.8%-113.9%) were consistent, precise, and reproducible at different quality control levels in accordance with FDA guidance. The assay was successfully used in the cellular pharmacokinetics study of DOX-S-DOX, which may provide a clue to explore analytical methods of other prodrug forms of DOX.

The Role of CBS in Injury Time Estimation after Brain Contusion / 法医学杂志

OBJECTIVES@#To observe the changes of cystathionine β-synthase （CBS） expression in the cerebral cortex after brain contusion at different times.@*METHODS@#An experimental model of traumatic brain injury （TBI） in mice was established by an improved weight-drop device. Then Western blotting and immunohistochemical examination were used to detect the CBS expression in cerebral cortex around injury at different time points （1 h, 6 h, 12 h, 1 d, 2 d, 3 d, 7 d）.@*RESULTS@#The results of Western blotting revealed that the expression level of CBS was down-regulated and reached its lowest level at the 3rd days after injury, and then restored to normal level after 7 days. The results of immunohistochemistry showed that CBS was present in the normal brain cortex. CBS expression gradually decreased at the 3rd days after injury, and then restored to normal level after 7 days.@*CONCLUSIONS@#CBS has the potential to be a reference index for time estimation after brain contusion in forensic practice.

Role of extracellular-signal regulated kinase cascade on cerebral ischemia and ischemic preconditioning in hippocampal neuron in gerbils / 中国应用生理学杂志

<p><b>AIM</b>To investigate the role of extracellular-signal regulated kinase (ERK) cascade on cerebral ischemia and ischemic preconditioning in hippocampal neuron.</p><p><b>METHODS</b>Male gerbils were randomly divided into sham group (SH), ischemia/reperfusion group (I/ R), ischemia preconditioning group (IP), specific antagonist of ERK-PD98059 (PD), solvent control groups (VE group), PD98059 combined with IP group (PIP). Forebrain ischemia was induced by occlusion of bilateral common carotid arteries and confirmed by isoelectricity of EEG. Observations were carried out in each group 15 min, 2 h, 4 h, 6 h, 1 d, 3 d, 5 d and 7 d after ischemia. Open field test was used to examine the spontaneous motor activity, the survival and apoptotic neurons, Fos and NF-kappaB masculine neurons in hippocampal CA1 region were counted, the expression of HSP70 in hippocampal CA1 region and p-ERK in hippocampal CA3/DG regions were detected by SABC immunocytochemical technique.</p><p><b>RESULTS</b>The spontaneous motor activity, the number of apoptotic neurons and NF-kappaB masculine neurons at 1 d, 3 d, 5 d, 7 d in CA1 region were much less in IP group than in I/R group (P < 0.01). The number of Fos masculine neurons at 15 min, 2 h, 4 h, 6 h, 1 d in CA1 region were significant more in IP group than in I/R group (P < 0.01). The expressions of p-ERK and HSP70 were significantly higher in IP group than in I/R group. The number of Fos masculine neurons at each point were more and apoptotic neurons at 1 d, 3 d were less in PD group than in I/R group. Results of observation in PIP group were within IP group and I/R group.</p><p><b>CONCLUSION</b>Activation of ERK in CA3/DG regions were related to ischemic tolerance. Induction of the expression of Fos and HSP70, decreasing of the product of NF-kB which might be one of the molecule mechanisms playing an important role in neural protection of ischemic preconditioning.</p>

The relationship between the effects of curcumin on cerebral ischemia/reperfusion injury and immediately genic expressions of fos, Jun and NF-kappaB in hippocampal CA1 area and its significance in gerbils / 中国应用生理学杂志

<p><b>AIM</b>To explore the relationship between the effects of curcumin on cerebral ischemic/reperfusion injury and immediately genic expressions of Fos, Jun and NF-kappaB in hippocampal CA1 area.</p><p><b>METHODS</b>Gerbils were randomly divided into sham group (SH), ischemia/reperfusion group (I/R), curcumin group (CU) and solvent control group (SC). Forebrain ischemia was induced by occlusion of bilateral common carotid arteries. Observations were carried out in each group 15 min, 1 h, 2 h, 6 h, 1 d, 3 d, 5 d and 7 d after ischemia: open field test was used to examine the behavioral change, the apoptosis neurons in hippocampal CA1 region was counted, the expression of Fos, Jun and NF-kappaB in hippocampal CA1 was detected by SABC immunocytochemical technique.</p><p><b>RESULTS</b>The behavioral mark and the number of apoptosis neurons in hippocampal (CA1 region was much less in CU group than in I/R group (P < 0.01) The expression of Fos was more and the expression of Jun and NF-kappaB was less in CA1 area in CU group than in I/R group (P < 0.01).</p><p><b>CONCLUSION</b>Curcumin can significantly protect neurons against cerebral ischemia, increasing the expression Fos and decreasing the expression of Jun and NF-kappaB may be the protective mechanisms.</p>

Effects of ischemic preconditioning on the expression of extracellular signal-regulated protein kinase and c-jun N-terminal kinase in hippocampus in a gerbil model of cerebral ischemia-reperfusion injury / 中华麻醉学杂志

Objective To investigate the effects of ischemic preconditioning (IP) on the expression of extracellular signal-regulated protein kinase (ERK) and c-jun N-terminal kinase (JNK) in hippocampus in a gerbil model of ischemia-reperfusion (I/R) injury and the role of ERK and JNK in the mechanism of ischemic cerebral preconditioning. Methods Gerbils of both sexes weighing 50-70kg were randomly divided into 4 groups : ( Ⅰ ) sham operation group; ( Ⅱ ) IP group; (Ⅲ) I/R group and ( Ⅳ ) IP + I/R group. Cerebral ischemia was produced by occlusion of bilateral common carotid arteries and confirmed by isoelectricity on EEG. In sham operation group bilateral common carotid arteries were exposed but not occluded. In IP and I/R groups the animals were subjected to 3 min (IP group) or 5 min (I/R group) cerebral ischemia respectively. In IP + I/R group the animals first underwent 3 min cerebral ischemia followed by 24h reperfusion and then were again subjected to 5 min cerebral ischemia. Open field test was performed to evaluate the behavioral deficit 1,3,5 and 7 days after ischemia. The animals were sacrificed at 15 min, 2, 4, 6h and 1, 3, 5, 7 days after ischemia. The brains were immediately removed for detection of apoptosis (TUNEL) and expression of p-ERK and JNK (immuno-histochemistry) in hippocampal CA1 and CA3 regions and microscopic examination. Results Compared with I/R group the behavioral deficit was significantly decreased and the number of living pyramidal neurons was significantly increased and apoptotic neurons significantly decreased in IP + I/R group. No p-ERK expression was detected in CA1 region in all of the 4 groups but in CA3 region the p-ERK expression was significantly higher in group IP + I/R than in group I/R. The p-JNK expression increased gradually during reperfusion in both CA1 and CA3 regions and was still detectable 7 days after ischemia and was significantly lower in CA1 region in group IP + I/R than in group I/R.Conclusion IP protects hippocampal neurons from I/R injury by inhibiting the expression of p-JNK in CA1 region and enhancing the activity of p-ERK in CA3 region