The search for novel surfactants or drug delivery systems able to improve the performance of old-generation antibiotics is a topic of great interest. Self-assembling amphiphilic calix[4]arene derivatives provide well-defined nanostructured systems that exhibit promising features for antibiotics delivery. In this work, we investigated the capability of two micellar polycationic calix[4]arene derivatives to recognize and host ofloxacin, chloramphenicol, or tetracycline in neutral aqueous solution. The formation of the nanoaggregates and the host–guest equilibria were examined by nano-isothermal titration calorimetry, dynamic light scattering, and mono- and bi-dimensional NMR. The thermodynamic characterization revealed that the calix[4]arene-based micellar aggregates are able to effectively entrap the model antibiotics and enabled the determination of both the species and the driving forces for the molecular recognition process. Indeed, the formation of the chloramphenicol–micelle adduct was found to be enthalpy driven, whereas entropy drives the formation of the adducts with both ofloxacin and tetracycline. NMR spectra corroborated ITC data about the positioning of the antibiotics in the calixarene nanoaggregates.

寻找能够改善旧式抗生素性能的新型表面活性剂或药物递送系统是引起人们极大兴趣的主题。自组装的两亲杯[4]芳烃衍生物提供了定义明确的纳米结构系统，这些系统展现出了有希望的抗生素递送功能。在这项工作中，我们研究了两种胶束聚阳离子杯[4]芳烃衍生物在中性水溶液中识别并容纳氧氟沙星，氯霉素或四环素的能力。通过纳米等温滴定量热法，动态光散射以及一维和二维NMR检验了纳米聚集体的形成和主客体平衡。热力学特征表明，基于杯[4]芳烃的胶束聚集体能够有效地捕获模型抗生素，并能够确定分子识别过程的种类和驱动力。确实，氯霉素-胶束加合物的形成被发现是焓驱动的，而熵却与氧氟沙星和四环素一起驱动加合物的形成。NMR光谱证实了ITC数据有关杯形芳烃纳米聚集体中抗生素的位置。