Investigation of CT imaging-based Bi2S3 drug-loaded nanoparticles for the diagnosis and therapy of colorectal cancer.

Colorectal cancer ranks as the third most prevalent cancer globally, with its incidence increasing in many developed countries. While chemotherapy demonstrates efficacy for certain patients, it is associated with significant side effects, and prolonged treatment may result in drug resistance. Consequently, this study synthesized Bi2S3 nanosheets via the solution-based method and integrated them with mesoporous silica exhibiting excellent pore channel properties to develop the Bi2S3@mSiO2-PEG/5-FU nanomaterials. Photothermal testing revealed that Bi2S3@mSiO2-PEG/5-FU exhibited superior photothermal heating performance, remarkable photothermal stability, and a photothermal conversion efficiency of 28.3 %, enabling effective photothermal therapy. The drug loading capacity of Bi2S3@mSiO2-PEG/5-FU was determined to be 24.8 %, with enhanced drug release under acidic conditions and laser irradiation, thereby improving chemotherapeutic efficacy and achieving synergistic effects between chemotherapy and photothermal therapy. Furthermore, Bi2S3@mSiO2-PEG demonstrated robust CT imaging capabilities (14.95 HU mg/mL), establishing the Bi2S3@mSiO2-PEG/5-FU nanomaterials as a platform with integrated diagnostic and therapeutic functionalities.