Patil-Sen Yogita, Sadeghpour Amin, Rappolt Michael, Kulkarni Chandrashekhar V
Centre for Materials Science, School of Physical Sciences and Computing, University of Central Lancashire.
School of Food Science & Nutrition, University of Leeds.
J Vis Exp. 2016 Feb 19(108):53489. doi: 10.3791/53489.
We present a facile method to prepare nanostructured lipid particles stabilized by carbon nanotubes (CNTs). Single-walled (pristine) and multi-walled (functionalized) CNTs are used as stabilizers to produce Pickering type oil-in-water (O/W) emulsions. Lipids namely, Dimodan U and Phytantriol are used as emulsifiers, which in excess water self-assemble into the bicontinuous cubic Pn3m phase. This highly viscous phase is fragmented into smaller particles using a probe ultrasonicator in presence of conventional surfactant stabilizers or CNTs as done here. Initially, the CNTs (powder form) are dispersed in water followed by further ultrasonication with the molten lipid to form the final emulsion. During this process the CNTs get coated with lipid molecules, which in turn are presumed to surround the lipid droplets to form a particulate emulsion that is stable for months. The average size of CNT-stabilized nanostructured lipid particles is in the submicron range, which compares well with the particles stabilized using conventional surfactants. Small angle X-ray scattering data confirms the retention of the original Pn3m cubic phase in the CNT-stabilized lipid dispersions as compared to the pure lipid phase (bulk state). Blue shift and lowering of the intensities in characteristic G and G' bands of CNTs observed in Raman spectroscopy characterize the interaction between CNT surface and lipid molecules. These results suggest that the interactions between the CNTs and lipids are responsible for their mutual stabilization in aqueous solutions. As the concentrations of CNTs employed for stabilization are very low and lipid molecules are able to functionalize the CNTs, the toxicity of CNTs is expected to be insignificant while their biocompatibility is greatly enhanced. Hence the present approach finds a great potential in various biomedical applications, for instance, for developing hybrid nanocarrier systems for the delivery of multiple functional molecules as in combination therapy or polytherapy.
我们提出了一种制备由碳纳米管（CNT）稳定的纳米结构脂质颗粒的简便方法。单壁（原始）和多壁（功能化）碳纳米管用作稳定剂，以制备皮克林型水包油（O/W）乳液。脂质即迪莫丹U和植烷三醇用作乳化剂，它们在过量水中自组装成双连续立方Pn3m相。使用探针超声仪在传统表面活性剂稳定剂或此处所用的碳纳米管存在下，将这种高粘性相破碎成较小的颗粒。最初，将碳纳米管（粉末形式）分散在水中，然后与熔融脂质进一步超声处理以形成最终乳液。在此过程中，碳纳米管被脂质分子包覆，进而推测这些脂质分子围绕脂质液滴形成颗粒乳液，该乳液可稳定数月。碳纳米管稳定的纳米结构脂质颗粒的平均尺寸在亚微米范围内，与使用传统表面活性剂稳定的颗粒相当。小角X射线散射数据证实，与纯脂质相（本体状态）相比，碳纳米管稳定的脂质分散体中保留了原始的Pn3m立方相。拉曼光谱中观察到的碳纳米管特征G和G'带的蓝移和强度降低表征了碳纳米管表面与脂质分子之间的相互作用。这些结果表明，碳纳米管与脂质之间的相互作用是它们在水溶液中相互稳定的原因。由于用于稳定化的碳纳米管浓度非常低，且脂质分子能够使碳纳米管功能化，预计碳纳米管的毒性可忽略不计，而其生物相容性则大大增强。因此，本方法在各种生物医学应用中具有巨大潜力，例如，用于开发用于递送多种功能分子的混合纳米载体系统，如联合治疗或多疗法。
