本文選題：胰島素 + pH敏感��； 參考：《南方醫(yī)科大學(xué)》2017年碩士論文

【摘要】：研究背景和目的:胰島素(insulin,INS)作為治療糖尿病的常用、必備藥物,存在生物膜滲透性差、半衰期短、易被胃腸道強(qiáng)酸、堿、酶滅活等缺陷,經(jīng)口服或其他非注射途徑給藥的生物利用度低,故臨床仍采取注射給藥的方式。但長期頻繁注射易造成峰谷濃度波動大,患者順應(yīng)性差。因此,為了發(fā)揮INS理想的治療效果,研究合適的藥物載體,發(fā)展INS緩控釋給藥體系是極其有必要的。故本文設(shè)計(jì)了一種pH敏感兩親性三嵌段聚合物,研究了其作為INS載體的載藥、釋藥性能以及體內(nèi)降血糖活性,以期為INS的緩控釋制劑開發(fā)提供參考。方法:1.結(jié)合ROP和ATRP反應(yīng)合成不同分子量的三嵌段聚合物,并用FT-IR和1H-NMR表征結(jié)構(gòu),芘熒光探針法測定臨界聚集濃度(CAC);2.采用納米沉淀技術(shù)制備載INS納米粒,動態(tài)光散射法(DLS)測定粒徑,透射電鏡(TEM)觀察粒子形態(tài);3.BCA法考察載藥情況和體外釋放行為,并以7個藥物釋放模型進(jìn)行擬合、分析,初步探討載INS納米粒的體外釋放機(jī)制;4.MTT法考察聚合物納米粒對L929細(xì)胞的毒性;5.建立STZ誘導(dǎo)的糖尿病大鼠模型,考察載INS納米粒的體內(nèi)降血糖效果。結(jié)果:1.FT-IR和1H-NMR結(jié)果確證了聚合物的結(jié)構(gòu)為聚乙二醇-聚己內(nèi)酯-聚甲基丙烯酸-N,N-二乙氨基乙酯(mPEG-PCL-PDEAEMA),其分子組成與預(yù)期設(shè)計(jì)一致說明了合成方法穩(wěn)定可控。聚合物的CAC值比普通小分子表面活性劑低3～6個數(shù)量級,表明其形成的納米粒具有較強(qiáng)的結(jié)構(gòu)穩(wěn)定性。2.聚合物自組裝行為具有pH敏感,形成的納米粒粒徑和形態(tài)會隨pH變化而改變。負(fù)載INS后納米粒的粒徑明顯增大,呈球形核殼結(jié)構(gòu)且粒徑分布均一。3.載藥實(shí)驗(yàn)表明90%wt投料比組的包封率(EE%)和載藥率(DL%)顯著優(yōu)于 70%wt(P0.001)、50%wt(P0.001)、20%wt(P0.001),其最高 EE%和DL%可達(dá)81.99±1.77%和42.46±0.53%。體外釋放結(jié)果顯示載INS納米粒有良好的緩釋行為且呈現(xiàn)pH敏感性,在pH 6.0釋放介質(zhì)中的釋藥速率明顯高于pH 7.4。其中,pH 6.0中的釋藥過程為Fick's擴(kuò)散,pH 7.4中的釋藥過程為Fick's擴(kuò)散和骨架溶蝕。載INS納米粒在二者中的釋放行為均與Weibull模型擬合效果最好,提示制劑存在釋放延遲,并且增長聚合物的疏水鏈段能有效降低藥物突釋量,延緩釋放。4.濃度≤0.4mg/ml時,聚合物納米粒對L929細(xì)胞無毒性。5.與INS相比,載INS納米粒在體內(nèi)呈現(xiàn)一定的緩釋效果且降血糖時間明顯延長。其中,INS-mPEG114-PCL86-PDEAEMA53納米粒組和INS-mPEG114-PCL114-PDEAEMA53納米粒組的降血糖時間可持續(xù)12h和48h,而INS組只能維持4h。結(jié)論:本文制得的聚合物載INS納米粒的理化性質(zhì)好,包封率和載藥率均較高,體外有良好緩釋且體內(nèi)降血糖時間明顯延長。故pH敏感兩親性三嵌段聚合物mPEG-PCL-PDEAEMA有望成為理想的INS緩釋載體。
[Abstract]:Background and objective: as a commonly used and necessary drug for the treatment of diabetes mellitus, INS has some defects such as poor permeability of biofilm, short half-life, and easily inactivated by gastrointestinal acid, alkali and enzyme. The bioavailability of oral or other non-injection drugs is low, so injection is still used in clinic. However, frequent injection for a long time can cause large fluctuation of peak and valley concentration and poor compliance of patients. Therefore, in order to give full play to the ideal therapeutic effect of INS, it is extremely necessary to study the appropriate drug carrier and develop the drug delivery system of INS. In this paper, a pH sensitive amphiphilic triblock polymer was designed to study the drug delivery, drug release and hypoglycemic activity of INS carrier in order to provide a reference for the development of slow and controlled release preparation of INS. Method 1: 1. Triblock polymers with different molecular weights were synthesized by the reaction of ROP and ATRP. The structure was characterized by FT-IR and 1H-NMR. The critical concentration of CACX 2 was determined by pyrene fluorescence probe method. INS nanoparticles were prepared by nano-precipitation technique. The particle size was measured by dynamic light scattering (DLS). The morphology of particles was observed by TEM. 3. BCA method was used to investigate the drug loading and in vitro release behavior. Seven drug release models were fitted and analyzed. A preliminary study on the release mechanism of INS nanoparticles in vitro. 4. The toxicity of polymer nanoparticles to L929 cells was investigated by MTT assay. STZ induced diabetic rat model was established to investigate the hypoglycemic effect of INS loaded nanoparticles in vivo. Results 1. The structure of the polymer was confirmed by FT-IR and 1H-NMR. The molecular composition of the polymer was stable and controllable. The molecular composition of the polymer was consistent with that of the expected design and the molecular composition of the polymer was confirmed to be pegylglycol-poly (caprolactone) -polymethacrylic acid-N-diethylaminoethyl ester (mPEG-PCL-PDEAEMAA). The CAC value of the polymer is 3 ~ 6 orders of magnitude lower than that of the ordinary small molecular surfactants, which indicates that the nanoparticles formed by the polymer have strong structural stability. 2. The self-assembly behavior of polymer is pH sensitive, and the particle size and morphology will change with the change of pH. After INS loading, the particle size of nanoparticles increased obviously, with spherical core-shell structure and uniform particle size distribution. The results of drug loading test showed that the encapsulation rate and drug loading rate of 90%wt group were significantly better than that of 70 WTT P0.001 and 50 WTX P0.001 and 20 WTT P0.001C, and the highest EE% and DL% reached 81.99 鹵1.77% and 42.46 鹵0.53% respectively. The drug loading test showed that the drug loading rate was significantly higher than that in the control group (P 0.001), and the highest EE% and DL% were 81.99 鹵1.77% and 42.46 鹵0.53%, respectively. The results of in vitro release showed that INS nanoparticles had good sustained release behavior and showed pH sensitivity, and the release rate in pH 6.0 release medium was significantly higher than that in pH 7.4. The drug release process in pH 6.0 is Fick's diffusion and release process in pH 7.4 is Fick's diffusion and skeleton dissolution. The release behavior of the nanoparticles loaded with INS was best fitted to the Weibull model, indicating that there was a release delay in the preparation, and the hydrophobic segment of the increased polymer could effectively reduce the amount of drug release and delay the release of .4. When the concentration 鈮，

本文編號：1990703