To develop an efficient vector for mitochondria-targeted drug delivery, we synthesized triphenylphosphonium (TPP)-modified glycol chitosan polymeric microspheres that had a unique chemical structure with both lipophilic phenyl groups and cationic phosphonium. Notably, TPP can easily pass through the phospholipid bilayer of mitochondria, thereby resulting in specific accumulation of a combined drug molecule in the mitochondria due to the membrane potential between TPP and its membrane. Therefore, TPP has been widely used as a mitochondria-targeting moiety. Triphenylphosphonium-glycol chitosan derivatives (GC-TPP and GME-TPP) with two different degrees of substitution (11% and 36%) were prepared by amidation and Michael addition. The chemical structures of GC-TPP and GME-TPP were characterized by ¹H nuclear magnetic resonance and Fourier-transform infrared spectroscopy, and their sizes were measured via field emission scanning electron microscopy and dynamic light scattering. Cellular uptake through flow cytometric analysis and confocal microscopy confirmed that both GC-TPP and GME-TPP were well introduced into cells, targeting the mitochondria. In addition, cytotoxicity testing of the most common cell lines, such as HEK293, HeLa, NIH3T3, and HepG2, indicated the absence of polymer toxicity. To evaluate the carrier effectiveness of TPP for drug delivery, doxorubicin (Dox) was used as an anticancer drug. Confocal microscopy images showed that Dox-loaded GME-TPP accumulated inside cells more than Dox-loaded GC-TPP. The anticancer effects of Dox were also determined by MTT assay, apoptosis/necrosis assay, and three-dimensional spheroids. In summary, the results indicate that GC-TPP and GME-TPP microspheres possess great potential as effective drug delivery carriers.

为了开发针对线粒体靶向药物递送的有效载体，我们合成了三苯基phosph（TPP）修饰的乙二醇壳聚糖聚合物微球，该微球具有独特的化学结构，具有亲脂性苯基和阳离子phospho。值得注意的是，由于TPP与其膜之间的膜电位，TPP可以容易地穿过线粒体的磷脂双层，从而导致组合药物分子在线粒体中的特异性积累。因此，TPP已被广泛用作线粒体靶向部分。通过酰胺化和迈克尔加成制备具有两种不同取代度（11％和36％）的三苯基phosph-乙二醇壳聚糖衍生物（GC-TPP和GME-TPP）。GC-TPP和GME-TPP的化学结构特征为¹H核磁共振和傅立叶变换红外光谱，并通过场发射扫描电子显微镜和动态光散射测量它们的大小。通过流式细胞术分析和共聚焦显微镜对细胞的吸收证实，GC-TPP和GME-TPP均已很好地引入细胞，靶向线粒体。另外，对最常见的细胞系（例如HEK293，HeLa，NIH3T3和HepG2）的细胞毒性测试表明没有聚合物毒性。为了评估TPP对药物输送的载体效力，阿霉素（Dox）被用作抗癌药物。共聚焦显微镜图像显示，载有Dox的GME-TPP积累的细胞多于载有Dox的GC-TPP。还通过MTT测定，凋亡/坏死测定和三维球体测定Dox的抗癌作用。