OBJECTIVE:To establish a method for simultaneous determination of lysophosphatidyl choline(LPC)and lysophos-phatidyl ethanolamine(LPE)in Nimodipine fat emulsion. METHODS:HPLC was performed on the column of Lichrosher Diol with detector of evaporative light scattering detector with mobile phase A of heptane- isopropyl alcohol solution(43∶57,V/V),mobile phase B n-heptane-isopropyl alcohol-water(29.5∶59∶11.5,V/V/V)(gradient elution)at a flow rate of 1.5 ml/min,column tempera-ture was 40℃,and the injection volume was 20 μl. RESULTS:The linear range was 0.020 0-0.400 0 mg/ml for LPC(r=0.999 0)and 0.010 0-0.200 0 mg/ml for LPE(r=0.999 6),and the logarithm value of concentration and peak area showed good linear relationship;the limit of quantitation was 0.013 4 mg/ml for LPC and 0.013 0 mg/ml for LPE;the limit of detection was 0.007 8 mg/ml for LPC and 0.007 6 mg/ml for LPE;RSDs of precision,stability and reproducibility tests were lower than 2%;recoveries were 95.96%-100.63%(RSD=1.83%,n=9)and 99.22%-101.76%(RSD=0.80%,n=9). CONCLUSIONS:The method is simple,and can be used for the determination of related substance in Nimodipine fat emulsion.

To study the relation between drug release and the drug status within curcumin-loaded microsphere, SPG (shirasu porous glass) membrane emulsification was used to prepare the curcumin-PLGA (polylactic-co-glycolic acid) microspheres with three levels of drug loading respectively, and the in vitro release was studied with high-performance liquid chromatography (HPLC). The morphology of microspheres was observed with scanning electron microscopy (SEM), and the drug status was studied with X-ray diffraction (XRD), differential scanning calorimetry (DSC) and infrared analysis (IR). The drug loading of microspheres was (5.85 ± 0.21)%, (11.71 ± 0.39)%, (15.41 ± 0.40)%, respectively. No chemical connection was found between curcumin and PLGA. According to the results of XRD, curcumin dispersed in PLGA as amorphous form within the microspheres of the lowest drug loading, while (2.12 ± 0.64)% and (5.66 ± 0.07)% curcumin crystals was detected in the other two kinds of microspheres, respectively, indicating that the drug status was different within three kinds of microspheres. In the data analysis, we found that PLGA had a limited capacity of dissolving curcumin. When the drug loading exceeded the limit, the excess curcumin would exist in the form of crystals in microspheres independently. Meanwhile, this factor contributes to the difference in drug release behavior of the three groups of microspheres.

Objective:To investigate the effect of heat shock protein B8 (HspB8) downregulation on retinal ganglion cell (RGC) and retinal function in the mice model of optic nerve injury (ONC).Methods:Adeno-Associated Virus (AAV) 2 AAV2-shHspB8-GFP was constructed to knockdown HspB8. 66 adult male C57/BL6 mice were randomly divided into the control group, the ONC group, the AAV2-shHspB8 group, the ONC+AAV2-shHspB8 group, and the ONC+AAV2-GFP group. There were 10, 20, 16, 10 and 10 mice respectively, and both eyes were used as experimental eyes. Western blot was used to evaluate the expression of HspB8 on day 3 and 7 after ONC. By GFP immunofluorescence staining, the efficacy of AAV2-shHspB8-GFP transfer was accessed. Moreover, it was possible to identify functional and RGC survival differences between groups by optomotor response (OMR), dark adapted full-field flash electroretinogram (ff-ERG), oscillatory potentials (OPs), photopic negative response (PhNR) and retinal flat-mount RGC counting 5 days after ONC. Comparisons between two groups were made using Mann-Whitney U test, unpaired t-test, unpaired t-test with Welch’s correction, one-way ANOVA, and Bonferroni t test. Results:Compared with the control group, the expression of HSPB8 protein in the retina of mice in ONC3 group was significantly increased, and the difference was statistically significant ( F=43.63, P<0.01). Compared with the control group, the ONC group showed obviously lower visual acuity ( P<0.01), lower a-wave, b-wave, OPs, PhNR amplitude, longer b-wave latency ( P<0.05), and the survival rates of RGC in ONC3 group, ONC5 group and ONC7 group decreased in a time-dependent manner( F=384.90, P<0.01). Transfection of AAV2 efficiency was highest on 4 weeks after IVT. Besides, there was no significant differences between the control group and the AAV2-shHspB8 group on visual acuity, ff-ERG, OPs, PhNR and RGC survival ( P>0.05). In comparison of the control group, we found that RGC survival of the ONC5+AAV2-shHspB8 group was significantly elevated ( F=10.62, P<0.01). Conclusions:Expression of HspB8 on the retina can be induced by ONC. The investigation of RGC counting, visual acuity, and ff-ERG revealed that optic nerve injury destructed functionality of mice retina and resulted to RGC death ultimately. The Most crucial finding of this research is that HspB8 knockdown had a neuroprotective effect in RGC after ONC.