Mesoporous SiO2@pH-responsive polypeptide nanocomposites: noninterventional embolization and ultrasound imaging combination theranostic for solid tumors

Abstract

Tumors theranostics will be a single but effective treatment in the future, while transcatheter arterial embolization (TAE) of solid tumors is currently an important clinical method, but TAE has some insurmountable defects. In order to innovate embolization and achieve tumor theranostics, herein, a new theranostic of noncatheter target embolization therapy combined with ultrasound imaging for solid tumors was developed using a series of triblock poly[(L-glutamic acid-ran-L-tyrosine)-b-L-threonine-b-L-cysteine]s-coating perfluoropentane-loaded mesoporous-SiO₂ nanoparticles (PFP-m-SiO₂@PGTTCs), and the gelled pH value of these nanoparticles was controlled by adjusting the ratio of L-glutamic acid to L-tyrosine in the copolymers. After the injection of PFP-m-SiO₂@PGTTCs aqueous solution into H22 tumor-bearing mice tail veins and VX2 tumor-bearing rabbits ear veins, over 80% of the model species survived one month later, imaging results indicated that PFP-m-SiO₂@PGTTC-6.2 can be used as an excellent ultrasound contrast agent, having specific tumor accumulation and completely occluding all levels of blood vessels at 12 h post-injection, and the tumors were inhibited and disappeared at 4 weeks post-injection. This pH-responsive noncatheter embolization system not only simplifies the procedure and elevates the compliance of conventional embolization therapy, but also provides a potential multifunctional theranostic candidate for solid tumor therapy.