Enhanced anticancer activity of N,N-bis(5-ethyl-2-hydroxybenzyl)methylamine (EMD) hydrophobic drug encapsulated in β-cyclodextrin nanosponges

N, N-bis (5-ethyl-2-hydroxybenzyl) methylamine (EMD) is a synthetic benzoxazine dimer compound. EMD targets and degrades the pro-oncogenic transcription factor c-Myc, initiating apoptosis in cancer cells. However, its use is restricted because of poor aqueous solubility and in physiological media. Cyclodextrin nanosponges (CN), a type of supramolecular macrocyclic polymer nanoparticles with hydrophobic cavities but soluble in water, are utilized here to load EMD in order to enhance its solubility. CNs with three different molar ratios of β-cyclodextrin (βCD)-to-citric acid crosslinker are synthesized: CN1 (βCD/citric acid 1:3), CN2 (βCD/citric acid 1:5), and CN3 (βCD/citric acid 1:8), and then loaded with EMD. EMD-CN2 exhibits a significantly higher solubilization efficiency (579.1 μg/mL) compared to the free EMD (59.09 μg/mL). The increased aqueous solubility of CN encapsulated EMD enhanced its anti-cancer efficacy. In vitro cytotoxicity, colony formation inhibition, and c-Myc suppression of EMD in cancer cells (A549 and HCT116) are improved over free EMD administration.