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. STATEMENT OF SIGNIFICANCE: Chemotherapy remains the most common modality for cancer treatment in clinical practice. Combination therapy by co-delivery of two or more therapeutic agents has been recognized as one of the most effective strategies to improve therapeutic outcome of cancer treatment. However, the ratio of loaded drugs could not be facilely optimized, which may greatly affect the combination efficiency and overall therapeutic outcome. Herein, we developed a hyaluronic acid based supramolecular nanomedicine with facile method to optimize the ratio of two therapeutic agents for improved therapeutic outcome. This supramolecular nanomedicine not only provides an important new tool for enhanced photodynamic therapy/chemotherapy of solid tumors, but also offers insights in using macrocyclic molecule-based host-guest complexation to facilely optimize the ratio of therapeutic agents in multi-modality nanomedicine.