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新型壳聚糖衍生物的合成及壳聚糖季铵盐用于钛片表面修饰的研究

Synthesis of Novel Chitosan Derivatives and Surface Functionalization of Titanium with HACC

【作者】 汪灵

【导师】 郭圣荣;

【作者基本信息】 上海交通大学 , 药剂学, 2010, 硕士

【摘要】 壳聚糖是一种天然来源的聚阳离子高分子材料,具有良好的生物可降解性、生物相容性和生物活性。首先,用壳聚糖和2, 3-环氧丙基三甲基氯化铵合成了5种不同取代度的壳聚糖季铵盐,并用红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)对其结构进行表征,测定了所合成壳聚糖季铵盐的溶解度、稀溶液pH稳定性、吸湿性等相关性质,同时对其成膜性、膜抑菌性作了初步研究。结果表明:壳聚糖季铵盐的溶解度、稀溶液pH稳定性和吸湿性随着壳聚糖季铵盐取代度的增加而增加;壳聚糖季铵盐具有良好的成膜性,所制得膜透明光滑,有一定的强度和韧性,对金黄色葡萄球菌和大肠杆菌的抑菌效果均明显优于壳聚糖膜。其次,依次通过piranha acid处理、硅烷化学反应、戊二醛处理,将壳聚糖季铵盐(DS:18%)化学键接到医用钛表面,从而制得壳聚糖季铵盐功能化钛片。并用x-射线光电子能谱(XPS)和全反射红外光谱(FT-IR/ATR)对每一步化学处理钛片进行表征。结果显示:随着每一步化学反应的进行,相对元素含量C/Ti、O/Ti逐渐增加。将壳聚糖季铵盐处理到戊二醛沉积的表面后,相对元素含量N/Ti从0.212增加到1.088;随着每一步化学处理,归属于TiO2的O 1s含量逐渐变小,从81%,72%,61%降到40%;归属于金属钛的Ti 2p 453.4 eV吸收峰逐渐变小。经过戊二醛和壳聚糖季铵盐处理的钛片表面,归属于金属钛的Ti 2p 453.4 eV吸收峰几乎消失;壳聚糖季铵盐功能化钛片表面出现了一系列特征吸收带,包括3365 cm-1 (-OH ),1664 cm-1 (Amide I),1165 cm-1 (νas, C-O-C桥)和958 cm-1–1155 cm-1(糖环的骨架振动和伯仲醇羟基的伸缩振动)。上述一系列结果说明壳聚糖季铵盐被成功键接到医用钛表面。最后,利用水相体系(chitosan-HOBt in the aqueous system)和有机相体系(SCC in the organic system)合成了两种新型低取代度的壳聚糖季磷盐(WSPCS DS:3.6%和WSPCS DS:4.2%)和两种新型高取代度的壳聚糖季磷盐(OSPCS DS:54.5%和OSPCS DS:81.7%)。FT-IR、1H-NMR、31P-NMR和XRD测定结果表明:WSPCS和OSPCS中均存在元素磷,且以磷盐的化学价态存在;WSPCS和OSPCS中原壳聚糖的结晶性均受到显著影响;与壳聚糖相比,WSPCS显著改善了其在水中的溶解性,OSPCS显著改善了其在有机溶剂如DMSO中的溶解性。

【Abstract】 Chitosan, a well-known abundant natural polycationic macromolecule with good biodegradability, biocompatibility and so on, gets much attention currently for biomedical application.Firstly, varies of 2-Hydroxypropyltrimethyl ammonium chloride chitosans (HACC) with different degree of substitution (DS: 6%, 18%, 37%, 54% and 81%) were synthesized by the reaction of chitosan with glycidyltrimethylammonium chloride (GTMAC), and characterized by FT-IR and 1H-NMR spectroscopy. Their properties such as water solubility, aqueous solution stability upon pH and moisture absorption ability were studied, following with the film-forming capability and the antibacterial property of films. Results indicated that the water solubility, aqueous solution stability upon pH and moisture absorption ability increased with increasing DS of HACC. Additionally, HACC films, prepared by tape casting with their dilute solutions, were presented as transparent films with favorable mechanical performance and better antibacterial property against Staphylococcus aureus and Escherichia coli than chitosan film.Secondly, HACC functionalized titanium was prepared by treating the pristine titanium with piranha acid oxidation, silanization procedure, glutaraldehyde reaction and HACC (DS: 18%) deposition successively. Each kind of chemical treated titanium was characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared attenuated total reflection (FT-IR/ATR). The results showed that with each reaction occurred, the atomic ratio of C/Ti and O/Ti gradually increased. Following the reaction of glutaraldehyde treated titanium with HACC, the atomic ratio of N/Ti rised from 0.212 to 1.088. With each reaction occurred, the content of O 1s attributed to TiO2 became smaller and smaller, from 81%, 72%, 61% to 40%. Also with each reaction carried out, the electron peak of Ti 2p at 453.4 eV due to Ti base gradually turned smaller and the peak almost diappearred after the titanium was treated with glutaraldehyde and HACC. Additionally, series infrared absorption bands were observed on the surface of HACC funtionalized titanium, including 3365cm-1 (-OH), 1664cm-1 (Amide I), 1165cm-1 (νas, C-O-C bridge) and the absorption bands between 958cm-1and 1155cm-1 (skeletal vibrations involving the C-O stretching of saccharide structure of HACC). All these results indicated that HACC was successfully covalently attached to medical titanium surfaces.Eventually, novel Water Soluble Phsophonium Chitosan Derivatives (WSPCS) were synthesized with differing degree of substitution (3.6% and 4.2%) of quaternary phosphonium by reacting chitosan with (2-Carboxyethyl) triphenylphosphonium chloride in a homogeneous system. At the same time, novel Organo Soluble Phosphnium Chitosan (OSPCS) were prepared with differing degree of substitution (54.5% and 81.7%) using chitosan-sodium dodecyl sulfate polyelectrolyte/surfactant complex in an organo system. All these compounds were characterized by FT-IR, 1H-NMR, 31P-NMR and x-ray diffraction (XRD). The results suggested that both WSPCS and OSPCS contained element of phsophonium. The crystallinity of not only WSPCS but also OSPCS was significantly influenced by the introduction of triphenylphosphonium group to chitosan backbone. WSPCS also showed improved water solubility, while the resulting OSPCS showed enhanced organo solubility compared to original chitosan.

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