Synthesis and inclusion study of a novel γ-cyclodextrin derivative as a potential thermo-sensitive carrier for doxorubicin

A novel γ-cyclodextrin (γ-CD) based carrier for molecular encapsulation of cancer chemotherapeutic agent doxorubicin (DOX) was synthesized and fully characterized by various analytical approaches. The γ-CD derivative, with a β-naphthyl alanine residue attached in its primary face, exhibits potent binding capacity with DOX. The encapsulation efficiency was assessed under various temperatures and pHs and it was demonstrated that the carrier-DOX inclusion complex is highly stable under a wide range of acidic conditions (pH 1.0-7.0); however, the encapsulated drug is slowly released under hyperthermic conditions (up to 50°C). Cell culture studies showed that the complexation of DOX with the carrier protected the drug from being uptaken by the cells and also greatly reduced its toxicity. Thermo-triggered DOX release was validated and the increase in cellular uptake was observed in in-vitro experiments. We concluded that this novel γ-CD derivative is able to effectively encapsulate DOX and the inclusion is responsive to temperature change, hence renders it a potential encapsulating agent for DOX delivery in combination with hyperthermia treatments.