Chitosan and it's derivatives have good biologic and particular physical and chemical properties. They have a wide applied foreground on drug preparations. This study introduced the recent advances of them based on widely researching the information and the actual works, and provided reference for the study of oral drug preparations.

AIM:To explore the interaction and function between ZnT3 mRNA expression and zinc elemental distribution in brain slice of mouse.METHODS:Zinc distribution was determined by SRXRF and ZnT3 mRNA expression in tissue was examined by RT-PCR method.RESULTS:Zinc content in cerebral cortex and hippocampus was significantly higher than that in other positions.The highest expression of ZnT3 mRNA was observed in cerebrum,hippocampus and testis.However,the ZnT3 mRNA was not detected in heart,liver,lung,spleen,kidney,intestine,olfactory bulb and cerebellum.CONCLUSION:ZnT3 facilitates the accumulation of zinc in synaptic vesicles and may play important roles in structuring of vesicular zinc pool.

Objective To prepare a red blood cells based multifunctional nanoscaled drug delivery system,and to study its in vitro photothermal and photodynamic effects.Methods The indocyanine green (ICG)/doxorubicin (DOX) co-loaded nanoscaled red blood cells (DIRAs) were prepared using an extrusion method.The morphology,particle size,encapsulation efficiency,and stability were determined.The heating related change of particle size was studied using a size and potential tester.The in vitro photothermal effect was studied using an infrared imaging device.The uptake of DIRAs to 4T1 cells was studied using a CLSM examination.The in vitro photodynamic effect was studied using a fluorescence probe and CLSM examination.Results DIRAs were successfully prepared with a uniform and homogeneous size which was about (97.0±20.1) nm.The Zeta potential was about-21.6 mV and the encapsulation efficiency of ICG and DOX were 93.5％ and 95.2％,respectively.The DIRAs had excellent stability within 28 days.This nanoscaled drug delivery system had identical photothermal effect compared to free ICG.The cellular uptake of DOX was significantly improved after the laser irradiation and the photodynamic effect was enhanced.Conclusions The prepared DIRAs have regular shape,suitable particle size,high encapsulation efficiency and high photothermal conversion efficiency.DIRAs can improve the cellular uptake of DOX and enhance the photodynamic efficiency.This biomimetic muhifunctional nano-system could facilitate breast cancer treatment by combining PTT7PDT and chemotherapy.

Objective:To prepare hollow copper selenide nanoparticles (Cu 2- xSe NPs), and investigate their photothermal properties and radiotherapy sensitization performance. Methods:Hollow copper selenide nanoparticles (Cu 2- xSe NPs) were prepared by sacrificial template method with Cu 2O NPs as sacrificial templates and with selenium powder as selenium source. The surface of copper selenide nanoparticles (Cu 2- xSe NPs) was modified with mercapto-ethylene glycol (mPEG-SH) to obtain Cu 2- xSe-PEG NPs. The morphology, particle size and ultraviolet spectrum of the Cu 2- xSe NPs were characterized by transmission electron microscopy, laser particle size analyzer and ultraviolet spectrophotometer. The photothermal properties and radiosensitization performance of the Cu 2- xSe-PEG NPs were investigated by infrared thermal imager and biological X-ray irradiator. Results:The obtained Cu 2- xSe NPs showed a hollow structure and good monodispersity, and the average diameter were (136.9±7.0) nm. The Cu 2- xSe NPs had absorption in the near-infrared region. When the Cu 2- xSe-PEG NPs sample with the mass concentration of 200 μg/ml were irradiated under 808 nm laser at 1.0 W/cm 2 for 10 min, the temperature raised to more than 55 ℃. The level of reactive oxygen species produced by the Cu 2- xSe-PEG NPs under X-ray irradiation was related to the concentration and radiation dose. Conclusions:The proposed preparation method can control the size of synthesized Cu 2- xSe NPs, and the Cu 2- xSe NPs had good photothermal properties and radiosensitization performance. This work will provide a certain theoretical basis for the application of Cu 2- xSe-PEG NPs in tumor thermoradiotherapy.

Objective: To investigate the in vitro and in vivo effects of 5-aminolevulinic acid (5-ALA)-mediated photodynamic therapy against oral squamous cell carcinoma (OSCC) and preliminarily explore the possible mechanisms. Methods: SCC25 cells were divided into the control group (5-ALA of 0 mg/L) and the experimental group (5-ALA of 10, 25, 50, 100 and 150 mg/L). The production of protoporphyrin Ⅸ (PpⅨ) induced by 5-ALA in SCC25 cells was detected using the flow cytometry. SCC25 cells were divided into the control group (5-ALA of 0 mg/L), lazer alone group, 5-ALA alone group (5-ALA of 100 mg/L) and the 5-ALA combined with laser irradiation group (5-ALA of 5, 10, 25, 50 and 100 mg/L), the cytotoxicity of 5-ALA combined with laser irradiation (wave length 635 nm, power density 87 mW/cm² and laser dose 10.4 J/cm²) was evaluated in SCC25 cells using the methyl thiazolyltetrazolium assay (incubation times of 4, 8 and 12 h in each group) and the induction effect of combination treatment on the cell apoptosis was assessed by the flow cytometry (incubation time of 12 h in each group). The intracellular production of reactive oxygen species (ROS) triggered by 5-ALA combined with laser irradiation was determined using a fluorescence probe method (incubation time of 12 h in each group). A mouse OSCC xenograft model bearing SCC25 tumor was built, and the mice were divided into control group (saline), 5-ALA group (5-ALA of 50 mg/kg) and 5-ALA combined with laser irradiation group (5-ALA of 10, 25 and 50 mg/kg). Antitumor effect of 5-ALA combined with laser irradiation (wave length 635 nm, power density 158 mW/cm² and laser dose 94.8 J/cm²) was further measured. Results: 5-ALA induced the production of PpⅨ in SCC25 cells in a drug concentration (0-150 mg/L)-and incubation time (0-24 h)-dependent manner. When the 5-ALA concentration was 100 mg/L, the intracellular PpⅨ production was in a relatively stable state. Cell viability and apoptosis rate of 5, 10, 25, 50, 100 mg/L 5-ALA combined with laser irradiation are, respectively, (82.3±5.2)%, (3.13±0.38)%; (74.6±9.3)%, (5.38±0.55)%; (38.3±9.7)%, (17.97±2.72)%; (9.2±3.8)%, (24.47±3.37)%; (7.2±0.8)%, (43.01±5.96)%, which indicated that 5-ALA combined with laser irradiation notably inhibited the growth of SCC25 cells and also induced significant cell apoptosis compared with the control group [(96.3±6.0)%, (0.35±0.13)%, P<0.05]. After combination treatment (5-ALA of 5, 10, 25, 50 and 100 mg/L combined with laser irradiation, the mean fluorescence intensity of dichlorofluorescein is (1.46±0.12)×10⁴, (2.16±0.30)×10⁴, (3.57±0.34)×10⁴, (81.70±13.05)×10⁴, (113.00±7.35)×10⁴, respectively, a large amount of ROS was produced in SCC25 cells compared with the control group [(0.96±0.15) ×10⁴, P<0.05], which was in positive correlation with the intracellular PpⅨ content. 5-ALA (concentration of 10, 25 and 50 mg/kg) combined with laser irradiation greatly suppressed the tumor growth in SCC25 tumor-bearing mice compared to the control group (P<0.05). Conclusions 5-ALA-mediated photodynamic therapy can trigger the generation of intracellular ROS that has significant cytotoxicity and apoptosis induction effect, and thus inhibit the tumor growth both in vitro and in vivo.