摘 要

一直以来，如何有效的治疗甚至治愈骨髓炎是所有临床医生都要谨慎对待的一个问题。经过长期的临床研究，局部给药治疗骨髓炎的效果明显，故众多医学研究者都这研究一种能在病变部位长时间有效释放药物并且载体材料能自行降解的药物释放系统。随着美国FDA批准可以将聚丙交酯、聚丙交酯乙交酯等高分子聚合物用于临床试验，温敏水凝胶在目前研究较热的药物输送系统领域越来越受到研究者的重视。本文设计了具有缓释控释的温敏水凝胶给药系统，并让水凝胶负载上现阶段能够有效杀死金黄色葡萄球菌的万古霉素。

在本研究中，我们通过开环聚合反应得到PLGA-PEG-PLGA聚合物并对其进行了相关表征，同时通过调节疏水段的长度，我们得到了几种具有不同相转变温度的PLGA-PEG-PLGA水凝胶，并对该水凝胶的相转变机理进行深入研究。

在低温条件下，将万古霉素溶于聚合物溶液，即完成了对药物的包封过程。在37 ℃条件下形成水凝胶后对万古霉素具有缓释作用，且在酸性环境下药物释放较快。体外细胞毒性实验表明所制备的水凝胶具有良好的细胞相容性，即所形成的水凝胶可注射到骨髓炎部位。包载万古霉素后，水凝胶也可起到近乎与纯万古霉素相当的杀菌效果。综上所述，在本研究中通过合成PLGA-PEG-PLGA从而制备得到的温敏水凝胶可以以注射的方式作用于病发部位，故其在对金黄色葡萄球菌所引起的骨髓炎的局部治疗方面具有优良医学应用前景。

相信本研究中制备的负载万古霉素的温敏水凝胶在对于骨髓炎的局部抗生素治疗研究中具有重大的参考与应用价值，为以后载药输送系统用于骨髓炎的临床治疗提供了重要参考。

关键词：骨髓炎；控制释放；温敏性水凝胶；抗菌；万古霉素

Abstract

Osteomyelitis has always been problems for the clinical workers,local application of drugs can achieve good clinical outcome. So looking for an effectively drug delivery strategy has always been an objective for the researcher.In recent years, the FDA has approved polymers such as poly lactide (PLA), poly lactic-co-glycolic acid (PLGA) to use in clinical trials,hence PLGA-PEG-PLGA temperature-sensitive hydrogel have received considerable attention for the researchers. we designed a useful system based on the drug delivery strategy, which was temperature-sensitive hydrogel drug delivery system.In this system,we use the vancomycin which was used as the model drug which is able to kill SA effectively.

In this study,we synthesized PLGA-PEG-PLGA by ring-opening polymerization which has good biocompatibility and biodegradability. By altering the length of the hydrophobic block,we obtained hydrogels with different phase transition temperatures. The mechanism of the phase transition of the hydrogel was studied.

At low temperature, encapsulation process was completed by directly dissolving vancomycin in the polymer solution. Hydrogel was formed at 37 ℃. It has the property of sustained drug release, and the release rate was higher in acidic environment. MTT assay showed that the prepared material has good biocompatibility to BMSCs, thus the prepared hydrogel solution can be injected into the site of osteomyelitis. After encapsulation of vancomycin, hydrogel showed bactericidal effect as good as pure vancomycin. Based on the above points, the temperature-sensitive hydrogel prepared in this study can be injected into skeletal sites, and has great potential for the application in the topical treatment of osteomyelitis which is caused by SA.

In conclusion,PLEG-PEG-PLEG trinlock thermosensitive hydeogel is an excellent injectable bimomaterials with good biodegradability and biocompatibility, and hold potential for osteomyelitis treatment.

Therefore,the injectable thermo-sensitive hydrogel system prepared in this study are of great value and provide important reference for the future application of drug delivery system in the clinical treatment of osteomyelitis.

Key words: Osteomyelitis,；Controlled release；Temperature-sensitive hydrogel；The antibacterial；Vancomycin

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 骨髓炎的概念及其治疗方法 1

1.1.1 骨髓炎 1

1.1.2 骨髓炎的治疗现状 1

1.2 药物载体输送系统 3

1.2.1 载药凝胶控制释放系统 3

1.2.2 抗菌药物载体系统 3

第二章 温敏水凝胶的制备及其表征 5

2.1引言 5

2.2 实验内容 6

2.2.1 实验材料与仪器 6

2.2.2 PLGA-PEG-PLGA的制备 6

2.2.3 PLGA-PEG-PLGA聚合物的表征 7

2.2.4 三嵌段共聚物胶束的制备 7

2.2.5 PLGA-PEG-PLGA水凝胶的制备 7

2.2.6 PLGA-PEG-PLGA水溶液的凝胶相图 7

2.2.7 万古霉素对水凝胶温敏性的影响 8

2.2.8 水凝胶的流变性能研究 8

2.3 实验结果与讨论 8

2.3.1 PLGA-PEG-PLGA三嵌段共聚物的制备 8

2.3.2 PLGA-PEG-PLGA三嵌段共聚物的表征 9

2.3.3 聚合物水溶液的相变研究 10

2.3.5 聚合物水溶液的流变性质研究 11

3.4 小结 12

第三章 负载万古霉素的温敏水凝胶的抗菌性能研究 13

3.1 引言 13

3.2 实验内容 14

3.2.1 实验材料与仪器 14

3.2.2 药物在水凝胶中的释放实验 14

3.2.3 PLGA-PEG-PLGA水凝胶的体外毒性试验 15

3.2.4 PLGA-PEG-PLGA水凝胶的抗菌性能研究 15

3.3 实验结果与讨论 16

3.3.1 负载万古霉素的PLGA-PEG-PLGA水凝胶的缓释结果 16

3.3.2 PLGA-PEG-PLGA水凝胶的细胞毒性研究 16

3.3.3 负载万古霉素的PLGA-PEG-PLGA水凝胶抗菌性能研究 17

3.4 小结 18

第四章 结论 19

参考文献 20

致 谢 22

第一章 绪论

1.1 骨髓炎的概念及其治疗方法

1.1.1 骨髓炎

骨髓炎是指化脓性细菌感染骨髓等骨组织器官而引起的一类炎症性疾病，大多数由血源性引起，也可以由外伤或手术感染引起^[1]。在骨髓炎患者的感染部位，革兰阳性菌是最常见的病原体，不过在如吸毒患者，镰刀型贫血症患者和严重的糖尿病患者之中，感染部位也有革兰阴性菌的存在。而真菌和分枝杆菌通常会引发慢性感染，由于其病变部位一般只在骨内且没有疼痛，感染者很难及时的发现并进行有效治疗。根据大量文献的报道，骨髓炎的主要致病菌为金黄色葡萄球菌，也有少数铜绿假单胞菌、链球菌等病例^[2,3]。