Selective binding and controlled release of anticancer drugs by polyanionic cyclodextrins

Publication date: Available online 10 March 2018
Source:Bioorganic & Medicinal Chemistry
Author(s): Jian-Guang Cheng, Hua-Jiang Yu, Yong Chen, Yu Liu
The binding stoichiometry, binding constants, and inclusion mode of some water-soluble negatively charged cyclodextrin derivatives, i.e. heptakis-[6-deoxy-6-(3-sulfanylpropanoic acid)]-β-cyclodextrin(H1), heptakis-[6-deoxy-6-(2-sulfanylacetic acid)]-β-cyclodextrin(H2), mono-[6-deoxy-6-(2-sulfanylacetic acid)]-β-cyclodextrin (H3) and mono-[6-deoxy-6-(3-sulfanylpropanoic acid)]-β-cyclodextrin (H4), with three anticancer drugs, i.e. irinotecan hydrochloride; topotecan hydrochloride; doxorubicin hydrochloride, were investigated by means of ¹H NMR, UV-Vis spectroscopy, mass spectra and 2D NMR. Polyanionic cyclodextrins H1-H2 showed the significantly high binding abilities of up to 2.6 × 10⁴∼2.0 × 10⁵ M^-1 towards the selected anticancer drugs, which were nearly 50-1000 times higher than the corresponding Ks values of native β-cyclodextrin. In addition, these polyanionic cyclodextrins also showed the pH-controlled release behaviors. That is, the anticancer drugs could be efficiently encapsulated in the cyclodextrin cavity at a pH value similar to that of serum but sufficiently released at an endosomal pH value of a cancer cell, which would make these cyclodextrin derivatives the potential carriers for anticancer drugs.

Graphical abstract

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