Integrated photothermal microcarriers for precise exosome-secreted microRNA profiling in breast cancer diagnosis

Breast cancer constitutes a significant global health burden,while conventional diagnosis approaches may lack precision and can be discomforting for patients.Exosomes have emerged as promising biomarkers for breast cancer due to their participation in diverse pathological processes,and a convenient analysis platform is believed to greatly promote its application.In this study,we propose a novel digital PCR approach utilizing near-infrared(NIR)photo-responsive thermosensitive microcarriers integrated with black phosphorus for quantifying microRNA(miRNA)biomarkers within exosomes.Petal-like biomimetic nanomaterials were firstly assembled for nonspecific exosome capture based on the affinity effect of avidin and biotin.Photothermal-responsive microcarriers,fabricated using gelatin-based substrates blended with photothermal nanocomposite,exhibited NIRinduced heating and reversible phase transition properties.We optimized synthesis parameters on thermal response and established a programmable and controllable NIR light source module.The results indicated a significant elevation in the levels of biomarkers miRNA-1246 and miRNA-122,with fold increases ranging from 6.2 to 23.6 and 5.9 to 13.0,respectively,in breast cancer cell lines MCF-7 and MDA-MB-231 compared to healthy control cells HUVEC.This study offers broad prospects for utilizing exosomes to resolve predictive biomarkers.