2.B.143.  The Carboxyl-modified Azocalix[6]Arene (CAC6A) Family

Medium-sized cargoes (e.g., drugs, probes, oligopeptides, and growth hormones) seem to be effective transport substrates of this carrier. Pmid  Hou et al. 2025 presented a negatively charged single molecular carrier, carboxyl-modified azocalix[6]arene (CAC6A), as a direct transmembrane tool that facilitates the transport of medium-sized cargoes. The cellular uptake pathway of CAC6A was identified using pharmacological inhibitors, and the direct transmembrane transport was confirmed. Further mechanistic transport investigations revealed that the modification group at the upper rim, the cavity size, and the appropriate amphiphilicity of CAC6A promoted direct membrane transport.