RGD peptide modified platinum nanozyme Co-loaded glutathione-responsive prodrug nanoparticles for enhanced chemo-photodynamic bladder cancer therapy

Bladder cancer is one of the most common malignant tumors in the urinary system worldwide. The poor permeability and uncontrollable release of drug and hypoxia of tumor tissues were the main reasons leading to poor therapeutic effect of chemo-photodynamic therapy for bladder cancer. To solve the above problems, a tumor-targeting peptide Arg-Gly-Asp (RGD) modified platinum nanozyme (PtNP) co-loaded glutathione (GSH)-responsive prodrug nanoparticles (PTX-SS-HPPH/Pt@RGD-NP) was constructed. Firstly, a GSH-responsive prodrug (PTX-SS-HPPH) was prepared by introducing a disulfide bond between paclitaxel (PTX) and photosensitizer 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH), which could realize the GSH-responsive release of the drug at the tumor sites. Also, the distearoylphosphoethanolamine-poly (ethylene glycol)-RGD peptide (DSPE-PEG-RGD) modified the prodrug to enhance the targeting and permeability ability to bladder cancer cells. Besides, to alleviate the hypoxia of tumor tissues, PtNP was introduced to produce oxygen (O₂) and improve photodynamic therapy efficiency. The results showed that the PTX-SS-HPPH/Pt@RGD-NP could achieve GSH-responsive drug release in tumor microenvironment, enhance the drug accumulation time and permeability at tumor sites in T24 subcutaneous tumor model and T24 orthotopic bladder tumor model, and alleviate hypoxia in tumor tissues, thus realizing enhanced chemo-photodynamic therapy for bladder cancer, and providing new strategies and methods for clinical treatment of bladder cancer.

Engineering glutathione-responsive near-infrared polymeric prodrug system for fluorescence imaging in tumor therapy

The release and biodistribution of drugs in the body have an important impact on tumor diagnosis and treatment. Near-infrared (NIR) fluorescent active fluorophores with good photostability are used to detect drug release and perform in vivo imaging. Here, we developed a glutathione-responsive NIR prodrug POEGMA-b-P(CPT-CyOH) (PCC) for effective cancer diagnosis and treatment, whereby the camptothecin (CPT) and NIR fluorophore CyOH in PCC are connected by disulfide bonds. In vitro experiments confirmed that PCC was quickly taken up by cells. The high concentration of tumor intracellular glutathione caused the cleavage of the PCC disulfide bonds, leading to the release of the chemotherapeutic drug CPT, indicating that PCC can promote apoptosis. Moreover, owing to the fluorescent properties of CyOH, PCC was successfully used for in vivo imaging to observe the drug penetration and enrichment capabilities in tumors. Finally, PCC successfully inhibited tumor growth, indicating that the prodrug has a good anti-tumor effect. This work provides new strategies for chemical drug delivery and precise cancer treatment.