Considering the significance of effective antigen presentation for boosting immune responses, it is essential to develop delivery systems for antigen presenting cells (APCs; dendritic cells and macrophages). As a simple and facile way for improving delivery efficiency of PLGA microspheres (MS) into APCs, we fabricated exosome-conjugated PLGA MS via polydopamine coating in this study. Spherical micro-sized particles were first prepared by conventional water-in oil-in water (W₁/O/W₂) double emulsion and solvent evaporation methods and were observed by scanning electron microscopy (SEM). With increasing model protein (ovalbumin)/MS weight ratios, higher amounts of ovalbumin (OVA) were immobilized onto MS. After exosome (EXO) conjugation to MS via polydopamine coating, the amount of nitrogen was significantly increased on the surface of MS, indicating that EXO were successfully conjugated onto MS. EXO-coated dopamine MS (EXO-Dopa MS) exhibited significantly improved delivery into DC2.4 cells and RAW264.7 cells, compared with bare MS and Dopa MS. Therefore, EXO-Dopa MS could be used as effective carriers of immune stimulating biomolecules into APCs for cancer immunotherapy.

考虑到有效抗原呈递对于增强免疫反应的重要性，开发抗原呈递细胞（APC；树突状细胞和巨噬细胞）的递送系统至关重要。作为提高PLGA微球（MS）向APC输送效率的简便方法，我们在本研究中通过聚多巴胺涂层制备了外泌体偶联的PLGA MS。首先通过常规的水包油型水（W ₁ / O / W ₂）双重乳液和溶剂蒸发方法，并通过扫描电子显微镜（SEM）进行观察。随着模型蛋白（卵清蛋白）/ MS重量比的增加，更高数量的卵清蛋白（OVA）被固定在MS上。通过聚多巴胺涂层将外泌体（EXO）与MS偶联后，MS表面的氮含量显着增加，表明EXO已成功偶联到MS上。与裸MS和Dopa MS相比，EXO包被的多巴胺MS（EXO-Dopa MS）表现出显着改善的对DC2.4细胞和RAW264.7细胞的递送。因此，EXO-Dopa MS可用作免疫刺激生物分子进入APC的有效载体，用于癌症免疫治疗。