Study Of The Therapeutical Effects Of BCNU-PLGA Sustained Release Microspheres On Rats C6 Glioma

[Objective]To explore the treatment effect of sustained-release BCNU-PLGA microspheres on rat C6 glioma.[Method]1.For the preparation of testing solution,the BCNU-loaded PLGA wafer was put in cell culture medium and incubated in the CO₂ incubator for 4h,1d,2d,3d,7d,14d,21d.Rat C6 glioma cells were cultured in vitro.Then,the testing solutions prepared according to the time course schedule were added to the cultured C6 cells,and incubated for additional 24h.ELISA tested the impact of extracts on the MMP-9,b-FGF protein expression in vitro cultured rat C6 glioma cells.2.intracranial C6 rat glioma model was made by Stereotactic method,rat bearing glioma were divided into six groups under different treatment methods,the control group,the intracranial application of blank wafer group,the the intracranial application of BCNU raw drug group,the intravenous application of BCNU group,distant subcutaneous application of BCNU-PLGA group,the intracranial application of BCNU-PLGA group.Survival status of rats was observed in each group,then, survivals of rats in each group were compared,the survival curve was drawn. Rats were killed at different time points,specimens of brain were collected. Tumor morphological changes of different time points were compared in each group by HE staining.Rats tumor PCNA,Ki-67 expression and MVD in each group were measured by Immunohistochemical evaluation.[Result]1.testing solutions according to the time course schedule were added to the cultured C6 cells,during the effective release time(21 days),MMP-9,b-FGF protein level within the supernatant of the glioma cells can be lowered(P＜0.01,or P＜0.05), which showed a time-dependent effect.2.After Succeeded in establishing a brain glioma model of rats,rats were divided into six groups at random.Compared with the control group,intravenous injection group,the intracranial application of BCNU group,long-term micro-dose drug delivery group,the intracranial application of blank wafer group,respectively,did not show obvious extension of the survival(P＞0.05).The BCNU-PLGA wafer which was implanted next to the tumor could significantly prolong the survival span of rats(P＜0.01).3.In the HE staining slice,we found the tumor morphological changed after drug treatment. The density of cells decreased,karyopyknosis and apoptosis could easily been found.And in some region,we could find the necrosis,bleeding,also,Reduction in tumor blood vessels.4.Local administration of BCNU-PLGA wafer next to tumor demonstrated significant reduction of PNCA,Ki-67 expression of tumor cells,reducing MVD than intravenous injection group,local BCNU group,and long-term micro-dose drug delivery group.[Conclusion]1.During the whole effective release time(21 days),the extracts of wafer could reduce MMP-9, bFGF protein expression in the supematant of glioma cells.The effect was time-dependent,which showed the delayed release of the wafer and BCNU can reduce MMP-9,bFGF expression of C6 glioma cells.2.In the vivo experiment, intravenous injection group,the intracranial application of BCNU group, long-term micro-dose drug delivery group,the intracranial application of blank wafer group,respectively,did not show obvious extension of the survival,while the intracranial application of BCNU-PLGA wafer group did.The local delivery of BCNU-PLGA wafer significantly prolonged the survival of rat.3.Local administration of BCNU-PLGA wafer next to the tumor,compared with the intravenous injection group,local BCNU group,long-term micro-dose drug delivery group demonstrated significant anti-tumor cell proliferation and anti-angiogenesis effect,and the results of the experiment provided a theoretical basis on the interstitial chemotherapy.