摘要
目的研究壳聚糖(chitosan,CH)脱乙酰度(degree of deacetylation,DDA)对CH-甘油磷酸盐温控体系凝胶化行为的影响,同时比较其在凝胶形成前后的流变学行为差异。方法将DDA为70%、85%、90%和97%的CH粉末分别溶解于0.1mol/L的盐酸溶液,制备各DDA浓度为2%(w/v)的CH溶液样品,每种DDA制备5个样品,于10℃下与五水甘油磷酸钠(β-glycerol phosphate disodium salt pentahydrate,GP)溶液混匀后,得到不同DDA的CH-GP温敏溶液。用AR2000ex流变仪在pH7.02条件下分别对CH-GP溶液和凝胶进行流变学以及物理性质表征测定。结果pH7.02条件下,DDA分别为85%、90%及97%的CH-GP温敏溶液,其初始凝胶化温度分别为(59.90±0.08)、(48.10±0.08)、(37.10±0.11)℃,凝胶化时间分别为(12.4±0.6)、(8.2±0.5)、(4.9±0.1)min;DDA为70%的CH-GP溶液凝胶化温度超过70℃,凝胶化时间超过15min。各DDA的CH样品凝胶化温度和凝胶化时间比较差异均有统计学意义(P<0.05)。CH-GP体系形成凝胶前,储能模量(G')和耗能模量(G'')最初均随频率升高而上升,至凝胶化温度点时2条曲线交汇,之后G'显著升高,G''则缓慢下降。形成凝胶后,随着频率升高,G'和G''均无明显改变。结论流变学表征可客观测定CH-GP体系的凝胶化温度以及凝胶的力学性能,因而这种方法在组织工程设计用于不同目的的支架时,有助于针对不同靶向组织选择合适DDA的CH原料。
Objective To evaluate the effect of deacetylation degree （DDA） on the gelation behavior of thermosensitive chitosan-β glycerol phosphate disodium salt pentahydrate （CH-GP） system and to compare their rheological behaviors before and after gelation. Methods A series ofthermosensitive CH-GP samples with different DDAs （70%, 85%, 90%, 97%） were prepared by dissolving CH with 0.1 mol/L HC1 solution, 5 samples for every single DDA, and then all these CH-GP solution samples processed the frequency sweep test and temperature sweep test （10-70℃ , 1 ℃/min） on AR 2000ex rheometer, with pH value of 7.02. Also, all the results of hydrogel samples were processed a frequency sweep test. Results With CH concentration of 2% （w/v） and pH value of 7.02, the gelating temperature of CH-GP systems with different DDAs （85%, 90%, 97%） were （59.90 ± 0.08）, （48.10 ± 0.08）, （37.10 ± 0.11） ℃ , respectively. While the gelating temperature of CH-GP system with 70% DDA was over 70℃. There were statistically significant differences in temperature and time of gelation among groups with different DDAs （P 〈 0.05）. Furthermore, storage modulus of such system raised from dozens Pa to a magnitude of several kPa during gelation, while loss modulus kept almost steady. Conclusion Gelating temperature and mechanical property of the system could be measured objectively by rheological characterization. Thus during designing tissue engineered scaffolds for various purposes, it is helpful applying selected CH with optimal DDA to different target tissues.
出处
《中国修复重建外科杂志》
CAS
CSCD
北大核心
2008年第7期861-863,共3页
Chinese Journal of Reparative and Reconstructive Surgery
关键词
壳聚糖
甘油磷酸盐
温敏凝胶
流变学表征
Chitosan Glycerolphosphate Thermosensitive hydrogel Rheological characterization
