【摘要】 目的:研究羧基功能化碳纳米管作为药物递送载体时,对抗肿瘤药物羟基喜树碱的装载与释放行为。方法:通过强酸氧化处理原始壁碳纳米管(MWCNTs)制得羧基功能化碳纳米管(f-CNTs),利用拉曼光谱表征MWCNTs羧基化前后的性质、元素分析和酸碱滴定法测定羧基的接枝量、扫描电子显微镜(SEM)和高分辨透射电子显微镜(HR-TEM)观察f-CNTs的微观形貌;采用湿化学法在f-CNTs中装载羟基喜树碱,利用高分辨透射电子显微镜(HR-TEM)观察羟基喜树碱在f-CNTs中的装载位置;最后考察该载药系统中羟基喜树碱的体外释放行为。结果:MWCNTs通过强酸处理后水溶性大大改善,长度由2μm左右减小至约200~300 nm,两端开口;且成功接枝上了羧基,元素分析和酸碱滴定测定羧基接枝量约为2~2.3 mmol/g;HR-TEM观察表明,羟基喜树碱装载在fCNTs的管腔中,其包载量约为120 mg/g;体外释放结果表明,96 h内,在p H=5.0时,HCPT从f-CNTs的管腔中累积释放量约为35%,当p H=7.4时,HCPT从f-CNTs的管腔中累积释放量不超过5%。结论:功能化的碳纳米管是溶解性能受介质酸碱性影响药物的良好控制释放递送载体,该递送系统在酸性微环境中释放药物,而在生理条件下较少释放药物。更多还原

【Abstract】 Objective To investigate the loading and release behavior of 10-hydroxycamptothecin( HCPT) within carboxylic multi-wall carbon nanotubes( f- CNTs). Methods Carboxylic multi- wall carbon nanotubes were prepared by strong acid treatment and characterized by elemental analysis,acid- base titration,Raman spectra,and scanning electron microscopy.HCPT was loaded within c-MWCNTs cavity by employing a wet-chemical method.The location of the HCPT within the fCNTs was confirmed by high-resolution transmission electron microscopy.The release action in vitro was studied at p H 5.0buffer solutions and p H 7.4 buffer solutions.Results The solution of f-CNTS was improved greatly than the primitive MWCNTs’ solution.The carboxyl groups grafting quantity of f-CNTs was approximately 2.0 ~ 2.3 mmol / g. HCPT was loaded into the inner hollow cavity of f-CNTs by capillary action with loading amount approximately 120 mg / g.Results of in vitro release revealed that cumulative release percentage of HCPT could amount to over 35% at p H 5.0 buffer solutions from HCPT-loaded f-CNTs compared with less than 5% at p H 7. 4 buffer solutions over a monitoring period of 96 h. Conclusion f- CNTs provide an alternative way as an acid responsive drug carrier for HCPT which could release loaded drugs in tumor acid micro-environment.Our results revealed f-CNTs can be employed as a potential acid labile anti-tumor drug carrier.更多还原