【作者】 公瑞煜；

【导师】 乔学亮；

【作者基本信息】 华中科技大学 ， 材料学， 2008， 博士

【摘要】 胆石症是一种严重危害人类健康的常见病、多发病,其中80%以上为胆固醇结石。大多数胆固醇结石患者愿意接受保守治疗,其中,口服鹅去氧胆酸（CDCA）、熊去氧胆酸（UDCA）有一定疗效,但该法疗程较长、疗效不尽人意,副作用较大。为改善CDCA对胆固醇结石的溶解作用,合成水溶性聚羧酸型梳状共聚物和C₆₀-梳状共聚物,用该聚合物修饰CDCA,利用其梳状侧链的熵排斥效应来增强CDCA溶解胆固醇结石的能力,探讨其在磷酸盐缓冲液（PBS液）和模拟胆汁中,增强CDCA溶解胆固醇结石的能力,以及溶解动力学机制。利用高分子设计理论,以烯丙基聚氧乙烯基醚（PAO）、顺丁烯二酸酐（MAn）、C₆₀和CDCA为原料,以偶氮二异丁腈（AIBN）为引发剂,合成具有梳状侧链结构的梳状共聚物-CDCA结合物和C₆₀-梳状共聚物-CDCA结合物,以IR、TLC和TEM法表征共聚物的结构,并在pH7.4的PBS液和不同胆固醇饱和指数（CSI）的模拟胆汁中进行溶石效果的研究,探讨在PBS液和不同CSI的模拟胆汁中结合物溶解胆固醇结石的效果和溶解动力学机制。IR、TLC和TEM分析结果均表明有梳状共聚物-CDCA和C₆₀-梳状共聚物-CDCA结合物生成。载体CMP30、CMP20、CMP4、CMO10、CMO7、CMO4粒径大小分别为:180、110、120、210、190、190 nm。溶石实验表明,在PBS液和不同CSI的模拟胆汁中,梳状共聚物-CDCA和C₆₀-梳状共聚物-CDCA结合物的溶石能力均高于CDCA对照组。对于梳状共聚物-CDCA系列结合物,在pH7.4的PBS液中,CDCA、MP40-CDCA、MP30-CDCA、MP20-CDCA、MP10-CDCA、MP4-CDCA、MOP10-CDCA、MOP7-CDCA、MOP4-CDCA在7d时的溶石率分别为:32.33%、62.76%、55.01%、82.53%、48.36%、37.5%、73.86%、58.13%、45.1%。CDCA、MP40-CDCA、MP30-CDCA、MP20-CDCA、MP4-CDCA的溶解速率分别为:5.33、9.615、6.868、17.59、5.717×10-5mg.cm-2.s-1。在CSI=0.6、CSI=1.0和CSI=1.6的模拟胆汁中,CDCA、MP4-CDCA、MP20-CDCA、MOP4-CDCA和MOP10-CDCA在7d的溶石率分别为:（1）CSI=0.6:29.08%、46.63%、74.5%、53.6%、67.5%, （2）CSI=1.0:12.2%、15.77%、21.7%、16.9%、20.5%,（3）CSI=1.6:6.69%、8.17%、21.6%、11.7%、18.3%。CDCA、MP20-CDCA、MP4-CDCA的溶解速率在CSI=0.6的模拟胆汁中,分别为:5.34、21.0、8.53×10-8mg.cm-2.s-1,CSI=1.0时,分别为:4.63、7.18、6.17×10-8mg.cm-2.s-1,CSI=1.6时,分别为:1.57、4.13、3.10×10-8mg.cm-2.s-1。对于C₆₀-梳状共聚物-CDCA系列结合物,在pH7.4的PBS液中,CDCA、CMP30-CDCA、CMP20-CDCA、CMP4-CDCA、CMO10-CDCA、CMO7-CDCA、CMO4-CDCA在7d时的溶石率分别为:10.06%、24.88%、51.563%、15.76%、35.83%、27.33%、19.31%。CDCA、CMP4-CDCA、CMP10-CDCA、CMP20-CDCA、CMP30-CDCA、CMP40-CDCA的溶解速率分别为:2.27、2.51、2.66、3.48、2.92、3.28×10-5mg.cm-2.s-1。目标产物是CDCA和C₆₀的新的水溶性聚合物。合成梳状共聚物-CDCA结合物最佳反应条件为:以AIBN为引发剂,其用量为占单体总质量的0.1%～1.0%左右,共聚温度为80℃,共聚时间为4.5h,以甲苯为脱水剂,脱水时间为3.5h,CDCA与梳状共聚物的反应时间以1.5h为宜。合成C₆₀-梳状共聚物-CDCA结合物最佳反应条件为:以AIBN为引发剂,引发剂用量为占单体总质量的0.1%～1.0%左右,自由基共聚温度为80℃,C₆₀的用量为PAO总质量的1%左右为宜,共聚合的时间为4～7h,以甲苯为脱水剂,脱水时间为3.5h,CDCA与梳状共聚物的反应时间以1.5h为宜。在PBS液和模拟胆汁中,结合物均有良好的溶石效果,且溶石效果均强于CDCA （P <0.05）,侧链长度和亲水亲油性对溶石效果均有影响。溶解动力学研究结果表明,在PBS液和CSI=0.6、1.0和1.6的模拟胆汁中,界面障碍是胆固醇结石溶解过程中的速率决定步骤,对胆固醇结石的溶解效果可以通过增加梳状共聚物侧链长度提高空间位阻能和选择适宜的亲水亲油平衡而得到改善。在PBS液中,MP20-CDCA、MOP10-CDCA、CMP20-CDCA和CMO10-CDCA的溶石效果最佳。在不同CSI的模拟胆汁中,MP20-CDCA和MOP10-CDCA的溶石效果最佳。更多还原

【Abstract】 Gallstones （GS） are common in the general population, which remain a main cause of serious morbidity and mortality. Cholesterol gallstone is more than 80% in all GS. Most of the cholelithiasis patient would like to accept non-surgical therapy, which is an important option especially for gallstone patients unsuitable for surgery because of age or coexisting disease, and for some patients who prefer not to undergo surgical procedures. Chenodeoxycholic acid （CDCA） and ursodeoxycholic acid （UDCA） are effective agents in certain circumstances for the dissolution of cholesterol gallstones. Unfortunately, stone dissolution by oral agents requires months to years of therapy. Furthermore, CDCA often causes diarrhea and aminotransferas elevations, and UDCA may cause stone calcification. To improve the effect of CDCA on dissolving cholesterol gallstone, the water-soluble copolymers as polycarboxylic acid of comb-like copolymers （PCC） and C₆₀-PCC were synthesized, which being used for modification of CDCA and strengthening effects of CDCA on dissolving the cholesterol gallstones by their entropy-repelled properties of comb-shaped side chains in buffers of phosphate （PBS） and in model bile.The design theory of polymer was mainly employed to synthesis the conjugate of PCC-CDCA and C₆₀-PCC-CDCA by C₆₀, polyoxyalkylene allylalkyldiether（PAO） and maleic anhydride（MAn）, which were copolymerized with AIBN as initiator, and then PCC or C₆₀-PCC were reacted with CDCA. The structures of the copolymers and the conjugates of PCC-CDCA and C₆₀-PCC-CDCA were confirmed with IR, TLC and TEM. The dissolving effects and the dissolution kinetics mechanism of cholesterol gallstone was inverstigated in PBS and in model bile of different cholesterol saturated index （CSI） at pH7.4, including PCC-CDCA or C₆₀-PCC-CDCA.It was showed that the conjugates of PCC-CDCA and C₆₀-PCC-CDCA were synthesized by results of IR, TLC and TEM. The diameter of CMP30, CMP20, CMP4, CMO10, CMO7 and CMO4 as carriers was 180, 110, 120, 210, 190 and 190 nm, respectively. It was determined that conjugates of PCC-CDCA and C₆₀-PCC-CDCA were better than controlled group with the results of gallstone dissolution in PBS and in model bile. With the PCC-CDCAs, the ratio of dissolving gallstone of CDCA, MP40-CDCA, MP30-CDCA, MP20-CDCA, MP10-CDCA, MP4-CDCA, MOP10-CDCA, MOP7-CDCA, and MOP4-CDCA was 32.33%, 62.76%, 55.01%, 82.53%, 48.36%, 37.5%, 73.86%, 58.13%, and 45.1% at 7d in PBS at pH7.4, respectively. The dissolution rate of CDCA, MP40-CDCA, MP30-CDCA, MP20-CDCA, and MP10-CDCA was 5.33, 9.615, 6.868, 17.59, and 5.717×10-5mg.cm-2.s-1 in PBS at pH7.4, respectively. In model bile, the ratio of dissolving cholesterol gallstone of CDCA, MP4-CDCA, MP20-CDCA, MOP4-CDCA and MOP10-CDCA was （1） CSI=0.6: 29.08%, 46.63%, 74.5%, 53.6%, and 67.5%, （2） CSI=1.0: 12.2%, 15.77%, 21.7%, 16.9%, and 20.5%, （3） CSI=1.6: 6.69%, 8.17%, 21.6%, 11.7%, and 18.3% at 7d, respectively. The dissolution rate of CDCA, MP20-CDCA, and MP4-CDCA was （1） CSI=0.6: 5.34, 21.0, and 8.53×10-8mg.cm-2.s-1, （2） CSI=1.0: 4.63, 7.18, and 6.17×10-8mg.cm-2.s-1, （3） CSI=1.6: 1.57, 4.13, and 3.10×10-8 mg.cm-2.s-1 in model bile, respectively. With the C₆₀-PCC-CDCAs, the ratio of dissolving gallstone of CDCA, CMP30-CDCA, CMP20-CDCA, CMP4-CDCA, CMO10-CDCA, CMO7-CDCA, and CMO4-CDCA was 10.06%, 24.88%, 51.563%, 15.76%, 35.83%, 27.33%, and 19.31% at 7d in PBS at pH7.4, respectively. The dissolution rate of CDCA, CMP4-CDCA, CMP10-CDCA, CMP20-CDCA, CMP30-CDCA, and CMP40-CDCA was 2.27, 2.51, 2.66, 3.48, 2.92, and 3.28×10-5mg.cm-2.s-1 in PBS at pH7.4, respectively.These cojugates were novel water soluble copolymers of CDCA and C₆₀. With PCC-CDCAs, the optimal conditions were obtained as follows: the concentration of initiator, AIBN, 0.1% - 1.0%, the copolymerization temperature 80℃, the reaction time 4.5h, the dehydration time, the reagent of dehydration is toluene, 3.5h, the reaction time of CDCA and comb-like copolymers 1.5h. With C₆₀-PCC-CDCAs, the optimal conditions were obtained as follows: the concentration of initiator, AIBN, 0.1% - 1.0%, the copolymerization temperature 80℃, the concentration of C₆₀ 1%, the reaction time 4-7h, the dehydration time, the reagent of dehydration is toluene, 3.5h, the reaction time of CDCA and comb-like copolymers 1.5h.Cholesterol dissolving effects in all PCC-CDCAs and C₆₀-PCC-CDCAs were significantly larger than in CDCA （P<0.005） in PBS and in model bile. The abilities of dissolving cholesterol gallstones were affected by the length of side chain and the properties of hydrophilic-lipophilic of comb-like copolymers. The dissolution kinetics studies suggest that the interfacial resistance was the dominant rate-determining factor on dissolving cholesterol gallstones both in PBS and in model. The effects of dissolving cholesterol gallstones can be improved by increasing the steric interactive potential energy of side chains of PCC-CDCAs and C₆₀-PCC-CDCAs, and taking into account the properties of hydrophilic-lipophilic of them. The MP20-CDCA, MOP10-CDCA, CMP20-CDCA and CMO10-CDCA have the most excellent effect of dissolving and dispersing to the cholesterol gallstones in all products in PBS. The MP20-CDCA and MOP10-CDCA also have the most excellent effect of dissolving and dispersing to the cholesterol gallstones in all products in these three model bile.更多还原