荷载rBMSC的新型可注射PEG水凝胶在骨修复中的应用研究

发布时间：2018-02-05 19:53

  本文关键词： 聚乙二醇 缩聚反应 巯-烯点击反应 可注射水凝胶 临界骨缺损 骨再生修复　出处：《浙江大学》2016年博士论文　论文类型：学位论文

【摘要】：当前人们对骨整形和口腔种植修复的需求越来越高,如何促进或加速骨再生修复,为骨整形或种植体植入创造良好的骨条件一直是众多学者研究的热点。本研究正是鉴于此设计并制备出一种新型的可注射原位成型PEG水凝胶,并进行了一系列全面的体内／外评价,主要研究结果和结论如下：1、先将寡聚乙二醇(OEG9)与硫代苹果酸(MSA)或马来酸酐(MA)在三氟甲磺酸钪(Sc(OTf)3)催化的温和条件下通过“一锅”法缩聚反应大量合成可降解的水溶性PEG衍生物POEGMS和POEGM;反应产率高达81%和87%,且产物中OEG和二酸的摩尔比非常接近初始投料比；核磁共振(1H NMR)谱图结果和凝胶渗透色谱(GPC)曲线等结果表明两种含有可点击基团(巯基和双键)的凝胶前体(POEGMS和POEGM)被成功合成,且无各自前体的残留。其次,通过巯-烯“点击”反应,所合成的水凝胶前体能在近似人体生理条件下(pH7.4和37℃)约30秒内迅速凝胶化形成三维网络骨架；其凝胶化时间可以通过pH值的微调以适应临床原位成型的实际操作需要；傅里叶变换红外谱图(FTIR)证明水凝胶前体中双键与巯基能全部高效地完成反应。2、一系列体外实验证明了10%固含量的水凝胶不但具有非常好的生物相容性和较好的机械强度(G’达69.2kPa),而且具有较低溶胀率(小于50%)和合适的降解速度(2W内几乎很少分解)；成骨前体细胞(MC3T3-E1)和大鼠骨髓间充质干细胞(rBMSC)能在水凝胶表面较好的粘附、铺展和增殖,在成骨诱导性培养条件下能成功地发生成骨向分化；二种细胞在水凝胶内部均能三维生长,其细胞团块能成功地侵入凝胶内部生长；水凝胶荷载rhBMP-2后在近似生理条件下的释放能维持达2周之久,并对在凝胶表面黏附生长和凝胶内部三维生长的rBMSC的增殖和成骨分化有明显促进作用。3、大鼠颅骨临界骨缺损(CSD)植入实验结果表明：单纯的水凝胶植入后,其本身就能促进大鼠颅骨CSD缺损骨修复再生；当荷载rBMSC的水凝胶体内植入8w后就能达到缺损的骨性封闭；当同时荷载rhBMP-2和rBMSC时,其骨修复再生能力有了大幅度提高,在4w时就几乎完成CSD缺损部位的大部分的骨质修复再生,无论在新骨体积分数和骨小梁结构形成上都明显优于其他组别。综上所述,本研究所制备的可注射原位成型PEG水凝胶是一种合成制备方法简单、使用方便具有很好临床应用前景的新型骨增量材料。
[Abstract]:At present, there is a growing demand for bone orthopedics and dental implants. How to promote or accelerate the repair of bone regeneration. To create a good bone condition for bone plastic or implant implantation has been the focus of many scholars. In this study, we designed and prepared a new injectable in-situ molding PEG hydrogel. A series of in vitro / in vivo evaluations were carried out. The main findings and conclusions are as follows: 1. OTf3) was prepared by using oligosyleneglycol (OEG9) or maleic anhydride (MSA) or maleic anhydride (MAA) in Scandium trifluoromeesulfonate (SC). A large number of degradable water-soluble PEG derivatives POEGMS and POEGM were synthesized by "one-pot" Polycondensation under mild conditions. The yield of the reaction is as high as 81% and 87, and the molar ratio of OEG and diacid in the product is very close to the initial feed ratio. The results of 1H NMR and GPC showed that two kinds of gel precursors containing clickable groups (mercapto and double bonds) were POEGMS and POEGM). Was successfully synthesized. And there was no residue of their precursors. Secondly, through the mercapto "click" reaction. The synthesized hydrogel precursor can rapidly gel to form a three-dimensional network skeleton within about 30 seconds under similar physiological conditions (pH 7.4 and 37 鈩，

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