OBJECTIVE:To prepare the gene recombined human interferon-alpha poly(lactic acid-co-glycolic)microspheres and study its physicochemical properties.METHODS:Interferon-? microspheres were prepared by W/O/W solvent extraction technique;the in vitro release of microspheres were examined;the rudimental organic solvent was determined with GC-MS.RESULTS:The IFN-?-MS were regular in their morphology,and the particle size distribution was narrow.The average diameter was 45.54?m.The encapsulation rate and the loading efficiency were 83.49% and 8.03%,and the in vitro accumulative release rate was 80.32% in 30 days.The in vitro interferon-? release from the microspheres was best described using Higuchi diffusion model.The rudimental of dichloromethane was less than 0.05%.CONCLUSIONS:The prepared IFN-?-MS is very good in all aspects of its physicochemical properties.

ObjectiveTo investigate the effect of individual donation-nucleic acid amplification test (ID-NAT) and minipool of 16 donations-NAT (P16-NAT) on the results of NAT of blood donors.Methods From February 2009 to June 2009,samples randomly collected from voluntary blood donors in Beijing were tested individually or in pooling of 16 donations by the PROCLEIX ULTRIO assay.For ID-NAT reactive samples with HBsAg,anti-HCV,or anti-HIV serologically unqualified,ID-NAT repeat reactive samples with serologically qualified,and P16-NAT reactive and followed resolution ID-NAT reactive samples,were performed for further discriminatory assays for HIV-1,samples and followed resolution ID-NAT reactive samples,were performed for further discriminatory assays for HBV,HCV and HIV-1discriminatory reagents.Samples which were HBV NAT + alone with serologically qualified were further quantified and confirmed of HBV DNA by Roche HBV quantitative PCR,analyzed by HBV serology and were diluted to simulate if they could be detected in P16-NAT.Results ( 1 ) Among 7613 samples tested by ID-NAT,26 were NAT positive,i.e.the ID-NAT positive rate was 0.34％ ( 26/7613 ). ( 2 ) Among 1004 P16 samples from 16 064 blood donations,27 were NAT positive,i.e.the P16-NAT positive rate was 0.17％ (27/16 064).(3)In serological qualified donations,ID-NAT yield rate (1 in 826,9/7438 ) was much higher than P16-NAT ( 1 in 7875,2/15 750) (x2 =11.880,P ＜ 0.05 ).All these 9 ID-NAT positive and 2 P16-NAT positive donations were discriminated as HBV NAT positive.There were no HCV NAT yield or HIV NAT yield samples. (4) Dilution assay showed only 2 of the 9 (22.22％ ) ID-NAT HBV yields were detected by P16-NAT.(5)Eight ID-NAT and 2 P16-NAT positive samples were quantified for HBV DNA and confirmed as HBV NAT yield,although the virus loads were very low:2 samples had HBV viral loads of 15 IU/ml and 472 IU/ml,6 samples ＜ 12 IU/ml,and 2 could not be detected in the original samples while had ＜ 12 IU/ml and 14.3 IU/ml in the 10 times concentrated samples.(6)Among 11 HBV NAT yield cases,3 (27.3％ ) were possible HBV window-period donors with all HBV seromarkers negative,the other 8 (72.7％ ) had occult HBV infections with anti-HBc or anti-HBe positive,however anti-HBc IgM negative.(7) The rate of initial P16-NAT reactive pools needed to be further tested by ID-NAT was 2.49％(25/1004).Initial P16-NAT reactive pools which caused by serologically qualified donations was 0.20％(2/1004).ConclusionsHBV NAT yield cases are detected at a higher frequency with ID-NAT than P16-NAT.In order to avoid samples with low viral loads would be undetected,NAT assay with high sensitivity should be selected and tested in minimized minipool donations or even with individual donation.

Objective: To evaluate the effect of semaphorin 3A (Sema3A) pre-treated bone marrow mesenchymal stem cells (BMSC) sheets on new bone formation in type 2 diabetes mellitus rats. Methods: Type 2 diabetes mellitus (T2DM) were induced by injection of streptozotocin, and the BMSC were isolated, controlled, identified and induced into cell sheets. Fifteen T2DM rats were randomly divided into control, sheets and Sema3A-sheets group and the calvarial critical size defect (CSD) model of rats were established. The defect zone of rats from control group were implanted with bone powder. The defect zone of rats from sheets group were implanted with bone powder and BMSC sheets. The defect zone of rats from Sema3A-sheets group were implanted with bone powder and BMSC sheets pretreated with 1.0 mg/L Sema3A. After 8 weeks, the bone samples were harvested and analyzed by micro-CT scanning, HE staining for the evaluation of new bone formation, and the immunohistochemical analysis for the expression of osteogenesis-related proteins including type Ⅰ collagen (COL- Ⅰ ), bone morphogenetic protein-2 (BMP-2), and osteocalcin (OCN). Results: The BMSC were isolated and cultured, and oil red O and Alizarin red S staining proved the multi-potential differentiation. Eight weeks after the establishment of calvarial CSD model, Sema3A-sheet group showed the most abundant new bone formation (0.516±0.070), with increased bone volume fraction, namely bone volume/tissue volume (BV/TV) compared with sheets group (0.319±0.050) and control group (0.224±0.037) (P<0.05), and the sheets group showed increased BV/TV compared with control group (P<0.05). While trabecular thickness (Tb.Th) control group showed no difference in three groups (P>0.05). HE staining also confirmed that Sema3A-sheets group showed the most new bone formation. Sheet group (0.174±0.051) compared showed difference with control group (0.099±0.033) (P< 0.05), and Sema3A-sheet group (0.421±0.069) showed increased bone formation compared with sheet group and control group (P<0.05). Immunohistochemistry showed that BMSC sheet increased the expression of osteogenesis-related proteins including COL-Ⅰ, BMP-2 and OCN, while Sema3A pretreatment showed more obvious increase of the expression of COL-Ⅰ and OCN. Conclusions The combined implantation of bone powder and Sema3A stimulated BMSC sheets significantly increased bone regeneration in vivo. Therefore, Sema3A pre-treated BMSC sheets transplantation provides a new strategy for restoring bone defect in T2DM.