Delivery Of A Chemotherapeutic Drug Using Novel Hollow Carbon Spheres For Esophageal Cancer Treatment

Esophageal cancer is one of the most common malignant tumors in China,among which squamous cell carcinoma accounts for more than 90%.The symptoms of early esophageal cancer were not obvious,and most patients have been diagnosed at the advanced stage.At present,surgery is the main treatment for resectable esophageal cancer,but surgical treatment alone was not satisfactory.Many patients cannot prevent tumor recurrence and distant metastasis by surgery alone,and need to be combined with chemotherapy or radiotherapy.There are adverse reactions in medical treatment,such as weak selective inhibition of tumor cells and high toxicity.How to overcome the toxic and side effects caused by non-targeted chemotherapy drugs as far as possible has always been a hot spot of clinical concern.It is a promising drug delivery method to construct a targeted drug delivery system with nanotechnology,which can improve the local drug concentration in the target tissue,reduce systemic toxic and side effects,and achieve efficient and safe drug delivery.Therefore,we developed a novel drug delivery system using hollow carbon sphere(HCS)using glucose,the basic energy substance of organisms.In addition to demonstrating their ease of synthesis for large-scale production,we also demonstrated in vitro that the HCS possessed high drug-loading capacity,lower cell toxicity,and optimal drug release profile at low pH,similar to the pH in the tumor microenvironment.The morphology,performance,in vivo and in vitro toxicity,biological distribution and anti-tumor activity of HCS were detected by scanning electron microscope,transmission electron microscope,spectrograph,flow cytometry,laser confocal,in vivo fluorescence imager and other techniques.The HCS also displayed excellent immunocompatibility and could rapidly distribute themselves in the cytoplasm to escape lysosomal clearance.More importantly,the HCS could efficiently deliver doxorubicin to tumor sites,which resulted in significant inhibition of tumor growth in an esophageal xenograft cancer model.This also prolonged the circulation time and altered the biodistribution of the drug.In conclusion,this study successfully constructed a new drug delivery system for tumor targeted therapy,providing a new treatment method for tumor patients,which has great application prospects in clinical treatment.