Development of Injectable Thermosensitive Nanocomposite Hydrogel for Ratiometric Drug Delivery to Treat Drug Resistant Chondrosarcoma In Vivo

Chondrosarcoma(CS), a prevalent primary malignant bone tumor, frequently exhibits chemotherapy resistance attributed to upregulated anti-apoptosis pathways such as the Bcl-2 family. In this manuscript, a new strategy is presented to augment chemosensitivity and mitigate systemic toxicity by harnessing a nano-enabled drug delivery hydrogel platform. The platform utilizes "PLGA-PEG-PLGA", an amphiphilic triblock copolymer combining hydrophilic polyethylene glycol (PEG) and hydrophobic polylactide glycolide (PLGA) blocks, renowned for its properties conducive to crafting a biodegradable, temperature-sensitive hydrogel. This platform is tailored to encapsulate a ratiometrically designed dual-loaded liposomes containing a first-line chemo option for CS, Doxorubicin (Dox), plus a calculated amount of small molecule inhibitor for anti-apoptotic Bcl-2 pathway, ABT-737. In vitro and in vivo evaluations demonstrate successful Bcl-2 suppression, resulting in the restoration of Dox sensitivity, evident through impeded tumor growth and amplified necrosis rates at the tumor site. This delivery system showcases remarkable thermal responsiveness, injectability, and biodegradability, all finely aligned with the clinical demands of CS treatment. Collectively, this study introduces a transformative avenue for tackling drug resistance in CS chemotherapy, offering significant clinical potential.