本文選題：納米水凝膠　切入點(diǎn)：電場響應(yīng)　出處：《浙江大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：癲癇作為神經(jīng)系統(tǒng)常見的疾病之一,其藥物治療存在靶向性差,易引起毒副作用和耐藥等問題。癲癇的發(fā)作是腦內(nèi)神經(jīng)元陣發(fā)性異常超同步化電活動的結(jié)果,將癲癇灶點(diǎn)異常放電限制在局部并及時抑制,是阻止癲癇發(fā)作的關(guān)鍵。本文結(jié)合癲癇發(fā)作的電生理學(xué)機(jī)制和主動靶向技術(shù),構(gòu)建腦靶向電場響應(yīng)納米水凝膠。通過腦靶向肽介導(dǎo)納米載體靶向累積于腦部,并在癲癇發(fā)作之際,在消弱癲癇樣放電的同時快速釋放藥物,實(shí)現(xiàn)癲癇的高效治療。本文的主要研究內(nèi)容如下：1、電場響應(yīng)納米水凝膠的合成與評價。以甲基丙烯酸二甲胺基乙酯、苯乙烯和對苯乙烯磺酸鈉(Sodium 4-vinylbenzene sulfonate, NaSS)為單體,以N,N'-亞甲基雙丙烯酰胺為交聯(lián)劑,過硫酸鉀-焦亞硫酸鈉為氧化還原體系引發(fā)劑,通過無皂乳液共聚法合成具有電場響應(yīng)功能的納米水凝膠。所合成的納米水凝膠荷正電、粒徑在50-146 nm之間；納米水凝膠在水性介質(zhì)中可快速(1min)響應(yīng)電場變化,納米粒溶脹,粒徑變大,其變化程度與NaSS的含量有關(guān)；以苯妥英鈉(PHT)為模型藥物,干凝膠溶脹于藥物水溶液的方法制備負(fù)載PHT納米水凝膠；載藥納米水凝膠的體外釋放速率與其粒徑有關(guān),粒徑大于100 nm的載藥納米水凝藥物釋放速率相對較慢；同時藥物從納米水凝膠中的釋放具有電場響應(yīng)特性,100μA電場作用1 min后,其在0.5 h時的藥物釋放量最大可增加0.71倍,其增加倍數(shù)與納米水凝膠中的NaSS含量有關(guān)。通過調(diào)整納米水凝膠的組成篩選得到理想的電場響應(yīng)納米水凝膠用于后續(xù)研究。2、腦靶向電場響應(yīng)納米水凝膠的合成與評價。為了實(shí)現(xiàn)納米水凝膠的腦部傳遞,利用腦靶向多肽Angiopep-2對納米水凝膠進(jìn)行修飾。在納米水凝膠處方中添加兩端具有反應(yīng)活性的琥珀酰亞胺聚乙二醇丙烯酸酯,合成聚乙二醇修飾的納米水凝膠,再利用納米水凝膠表面聚乙二醇鏈段末端的琥珀酰亞胺與多肽Angiopep-2中氨基的化學(xué)反應(yīng),制備Angiopep-2修飾納米水凝膠(ANG-ERHNPs). ANG-ERHNPs保持了電場快速響應(yīng)功能；ANG-ERHNPs在bEnd.3細(xì)胞上表現(xiàn)為低毒性,IC50為449.0 μg/mL; ANG-ERHNPs有較好的跨體外BBB模型轉(zhuǎn)運(yùn)的能力,4h的累積透過百分率增加1倍,其機(jī)理可能與ANG-ERHNPs上的Angiopep-2與bEnd.3細(xì)胞表面蛋白的特異性結(jié)合,從而被bEnd.3細(xì)胞快速攝取有關(guān)；ANG-ERHNPs經(jīng)腹腔注射后,通過活體成像系統(tǒng)可觀察到其在大鼠腦組織和腦區(qū)累積；藥動學(xué)研究表明：大鼠腹腔注射給藥后,苯妥英鈉腦靶向電場響應(yīng)納米水凝膠(ANG-PHT-ERHNPs)的相對生物利用度為PHT溶液組的1.91倍,且明顯延長了PHT在體內(nèi)的循環(huán)時間；組織分布結(jié)果表明：ANG-PHT-ERHNPs具有腦部轉(zhuǎn)運(yùn)能力,其腦靶向指數(shù)為2.56；ANG-PHT-ERHNPs腹腔注射給藥后,在癲癇相關(guān)腦區(qū)(皮層、海馬、杏仁核、小腦和腦干)均能測到藥物,Cmax提高近1倍,提示ANG-PHT-ERHNPs可以降低給藥劑量。3、腦靶向電場響應(yīng)納米水凝膠的抗癲癇藥效研究。分別采用最大電休克、杏仁核電點(diǎn)燃和戊四氮(Pentylenetetrazol, PTZ)三種大鼠癲癇模型,評價腹腔注射給予不同劑量的PHT溶液、ANG-PHT-ERHNPs、苯妥英鈉腦靶向非電場響應(yīng)納米水凝膠(ANG-PHT-HNPs)的抗癲癇作用。相比ANG-PHT-HNPs和PHT溶液,ANG-PHT-ERHNPs在三種癲癇模型中均具有更好的抗癲癇作用,不僅能降低有效治療劑量而且可以延長藥物的抗癲癇治療時間窗；PTZ誘導(dǎo)的癲癇模型上測得的游離PHT結(jié)果進(jìn)一步證實(shí)了PHT從ANG-PHT-ERHNPs中快速釋放與發(fā)作腦電的嚴(yán)重程度呈正相關(guān)。
[Abstract]:One of the common diseases of nervous system as epilepsy, drug therapy has poor targeting, easy to cause the problem of side effects and drug resistance. The seizure is the brain neurons abnormal synchronization of paroxysmal electrical activity results, the abnormal discharge of epileptic foci in the local limit and prevent seizures, key this combination of seizures. The electrophysiological mechanism and active targeting technology, construct the target brain response to the electric field. The nano hydrogel brain targeting peptide mediated tumor targeting accumulation in the brain, and seizures on the occasion, rapid release of drugs in epilepsy weakened epileptiform discharge at the same time, realize the efficient treatment of epilepsy the main contents of this paper are as follows: 1. The electric field response synthesis and evaluation of nano hydrogels. The methacrylic acid two methylamino ethyl ester, styrene and sodium styrene sulfonate (Sodium 4-vinylbenzene sulfonate, NaSS) as monomer, N, N'- methylene bis acrylamide as crosslinking agent, potassium persulfate and sodium metabisulfite as redox initiator, the soap free emulsion copolymerization method to synthesis nano hydrogel electric field response function. The positively charged nano hydrogel synthesis, particle size between 50-146 nm nano hydrogels; fast in water medium (1min) in response to the electric field change, nanoparticles swelling, particle size, content of the degree of change and NaSS; with phenytoin (PHT) as a model drug, preparation method of dry gel swelling in drug solution preparation load nanostructured PHT hydrogel; drug loaded hydrogel in vitro release rate with the particle size, drug loaded hydrogel drug particle size greater than 100 nm release rate is relatively slow; at the same time from the drug with nano hydrogel release in electric field response characteristics of 100 A electric field after 1 min in 0.5 h The maximum amount of drug release can be increased by 0.71 times, the increase of NaSS content in multiple and nano hydrogel. Through screening adjustment nanohydrogels ideal electric field response nano hydrogel for further study of.2 targeting to the brain electric field response synthesis and evaluation of nano hydrogels. In order to achieve nanohydrogels brain transfer to polypeptide Angiopep-2 the nano hydrogel modified by brain target. At both ends of adding polyethylene glycol acrylate succinimide nano hydrogel prescription with reaction activity, synthesis of polyethylene glycol modified nano hydrogel, and then the chemical reaction of amino succinimide and peptide Angiopep-2 nano hydrogel surface of polyethylene glycol chain end in the preparation of Angiopep-2 modified nano hydrogel (ANG-ERHNPs). ANG-ERHNPs the electric field rapid response function ANG-ERHNPs in bEnd.3 cells on the table; 鐜頒負(fù)浣庢瘨鎬，

本文編號：1602001