Gas‐Generating, pH‐Responsive Calcium Carbonate Hybrid Particles with Biomimetic Coating for Contrast‐Enhanced Ultrasound Imaging

This work reports the fabrication of biocompatible and pH‐sensitive hybrid polydopamine/bovine serum albumin/calcium carbonate (PDA/BSA/CaCO3) particles via a rapid precipitation method. These hybrid particles generate hyperechogenic carbon dioxide bubbles upon exposure to low pH environments, making them ideal as a contrast agent and detector for tumor cells. This study also highlights the application of red blood cell membrane (RBC)‐derived membranes as a biomimetic coating for PDA/BSA/CaCO3 hybrid particles in order to modulate protein corona formation, a natural physiological response that alters tailored properties of most nanomaterials that are administered systemically. Results of this work demonstrate that the RBC membrane‐coated hybrid particles are ideal for a wide range of biomedical applications, such as noninvasive multimodal imaging, photothermal and photodynamic therapy, and “personalized” drug delivery systems. Polydopamine/bovine serum albumin/calcium carbonate hybrid particles are pH‐responsive materials that produce hyperechogenic carbon dioxide bubbles, which are suitable for contrast‐enhanced ultrasound imaging. The combination of these hybrid particles and red blood cell membrane coating technology makes a biocompatible material, ideal for noninvasive multimodal imaging for diagnosis and theranostic applications.