Hyaluronic Acid-based Supramolecular Nanomedicine with Optimized Ratio of Oxaliplatin/Chlorin e6 for Combined Chemotherapy and O2-Economized Photodynamic Therapy

Dual- or multi-modality combination therapy has become one of the most effective strategies to overcome drug resistance in cancer therapy, and the optimized ratio of the therapeutic agents working on the tumor greatly affects the therapeutic outcomes. However, the absence of a facile method to optimize the ratio of therapeutic agents in nanomedicine has, at least in part, impaired the clinical potential of combination therapy. Herein, a new cucurbit[7]uril (CB[7])-conjugated hyaluronic acid (HA) based nanomedicine was developed, in which both chlorin e6 (Ce6) and oxaliplatin (OX) were co-loaded non-covalently at an optimized ratio via facile host-guest complexation, for optimal, combined photodynamic therapy (PDT)/chemotherapy. To maximize the therapeutic efficacy, a mitochondrial respiration inhibitor, atovaquone (Ato), was also loaded into the nanomedicine to limit consumption of oxygen by the solid tumor, sparing oxygen for more efficient PDT. Additionally, HA on the surface of nanomedicine allowed targeted delivery to cancer cells with over-expressed CD44 receptors (such as CT26 cell lines). Thus, this supramolecular nanomedicine platform with an optimal ratio of photosensitizer and chemotherapeutic agent not only provides an important new tool for enhanced PDT/chemotherapy of solid tumors, but also offers a CB[7]-based host-guest complexation strategy to facilely optimize the ratio of therapeutic agents for multi-modality nanomedicine.