Dong Ran, Gong Wenjian, Guo Qiuyun, Liu Hui, Yu Deng-Guang
School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, China.
Polymers (Basel). 2024 Sep 15;16(18):2614. doi: 10.3390/polym16182614.
Polymeric composites for manipulating the sustained release of an encapsulated active ingredient are highly sought after for many practical applications; particularly, water-insoluble polymers and core-shell structures are frequently explored to manipulate the release behaviors of drug molecules over an extended time period. In this study, electrospun core-shell nanostructures were utilized to develop a brand-new strategy to tailor the spatial distributions of both an insoluble polymer (ethylcellulose, EC) and soluble polymer (polyvinylpyrrolidone, PVP) within the nanofibers, thereby manipulating the extended-release behaviors of the loaded active ingredient, ferulic acid (FA). Scanning electron microscopy and transmission electron microscopy assessments revealed that all the prepared nanofibers had a linear morphology without beads or spindles, and those from the coaxial processes had an obvious core-shell structure. X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopic tests confirmed that FA had fine compatibility with EC and PVP, and presented in all the nanofibers in an amorphous state. In vitro dissolution tests indicated that the radical distributions of EC (decreasing from shell to core) and PVP (increasing from shell to core) were able to play their important role in manipulating the release behaviors of FA elaborately. On one hand, the core-shell nanofibers F3 had the advantages of homogeneous composite nanofibers F1 with a higher content of EC prepared from the shell solutions to inhibit the initial burst release and provide a longer time period of sustained release. On the other hand, F3 had the advantages of nanofibers F2 with a higher content of PVP prepared from the core solutions to inhibit the negative tailing-off release. The key element was the water permeation rates, controlled by the ratios of soluble and insoluble polymers. The new strategy based on core-shell structure paves a way for developing a wide variety of polymeric composites with heterogeneous distributions for realizing the desired functional performances.
用于控制封装活性成分持续释放的聚合物复合材料在许多实际应用中备受追捧；特别是，人们经常探索水不溶性聚合物和核壳结构，以在较长时间内控制药物分子的释放行为。在本研究中，利用静电纺丝核壳纳米结构开发了一种全新策略，以调整不溶性聚合物（乙基纤维素，EC）和可溶性聚合物（聚乙烯吡咯烷酮，PVP）在纳米纤维内的空间分布，从而控制负载的活性成分阿魏酸（FA）的缓释行为。扫描电子显微镜和透射电子显微镜评估表明，所有制备的纳米纤维均具有无珠或纺锤体的线性形态，而同轴工艺制备的纳米纤维具有明显的核壳结构。X射线衍射和衰减全反射傅里叶变换红外光谱测试证实，FA与EC和PVP具有良好的相容性，并以无定形状态存在于所有纳米纤维中。体外溶出试验表明，EC（从壳到核递减）和PVP（从壳到核递增）的径向分布能够在精细控制FA的释放行为中发挥重要作用。一方面，核壳纳米纤维F3具有由壳溶液制备的具有较高EC含量的均匀复合纳米纤维F1的优点，可抑制初始突释并提供更长的持续释放时间。另一方面，F3具有由核溶液制备的具有较高PVP含量的纳米纤维F2的优点，可抑制负拖尾释放。关键因素是由可溶性和不溶性聚合物比例控制的水渗透速率。基于核壳结构的新策略为开发具有异质分布的各种聚合物复合材料以实现所需的功能性能铺平了道路。
