School of Materials Science & Engineering, University of Shanghai for Science and Technology, 516 Jungong Road, Yangpu District, Shanghai 200093, China.
Acta Biomater. 2013 Mar;9(3):5665-72. doi: 10.1016/j.actbio.2012.10.021. Epub 2012 Oct 23.
The capability of core/sheath nanofibers prepared using coaxial electrospinning to provide adjustable biphasic drug release was investigated. Using ketoprofen (KET) as the model drug, polyvinylpyrrolidone as the sheath polymer, and ethyl cellulose as the core matrix, the coaxial process could be conducted smoothly and continuously without spinneret clogging. Scanning electron microscopy and transmission electron microscopy revealed linear nanofibers with homogeneous and clear core/sheath structures. Differential scanning calorimetry and X-ray diffraction verified that the core/sheath nanofibers were nanocomposites, with the drug present in the polymer matrix in an amorphous state. Attenuated total reflectance-Fourier transform infrared spectra demonstrated that the sheath polymer and core matrix were compatible with KET owing to hydrogen bonding. In vitro dissolution tests showed that the core/sheath nanofibers could provide typical biphasic drug release profiles consisting of an immediate and sustained release. The amount of drug released in the first phase was tailored by adjusting the sheath flow rate, and the remaining drug released in the second phase was controlled by a typical diffusion mechanism. The present study shows a simple and useful approach for the systematic design and fabrication of novel biomaterials with structural characteristics for providing complicated and programmed drug release profiles using coaxial electrospinning.
采用同轴静电纺丝制备的芯/鞘纳米纤维具有提供可调节双相药物释放的能力，本文对此进行了研究。以酮洛芬（KET）为模型药物，以聚乙烯吡咯烷酮为鞘聚合物，以乙基纤维素为芯基质，可顺利且连续地进行同轴工艺，而不会出现喷丝头堵塞的情况。扫描电子显微镜和透射电子显微镜显示出具有均匀清晰的核/壳结构的线性纳米纤维。差示扫描量热法和 X 射线衍射证实了芯/鞘纳米纤维是纳米复合材料，药物以无定形状态存在于聚合物基质中。衰减全反射-傅里叶变换红外光谱表明，由于氢键的作用，鞘聚合物和芯基质与 KET 相容。体外溶解试验表明，芯/鞘纳米纤维可提供典型的双相药物释放曲线，包括即刻释放和持续释放。通过调整鞘流率可控制第一阶段释放的药物量，而第二阶段剩余药物的释放则通过典型的扩散机制进行控制。本研究展示了一种简单而有用的方法，可通过同轴静电纺丝系统地设计和制造具有结构特征的新型生物材料，以提供复杂和程控药物释放曲线。
