MRI-traceable multifunctional magnetic mesoporous silica nanoparticles (MMSN) capped with graphene quantum dots (GQD) as a theragnostic system in colorectal cancer treatment

Abstract

In the study, a multifunctional nanosystem composed of magnetic core-mesoporous silica nanoparticles (MMSN) capped with graphene quantum dots (GQD) was proposed as a theragnostic platform against colorectal cancer cells. The theragnostic carrier was well characterized and had an average particle size of 140 nm, with a specific surface of 475.82 m2 g−1. The superparamagnetic nanoparticles showed a hysteresis loop, with a maximum magnetization of 14.93 emu.g−1 and a remanence of 2.64 emu.g−1. The functionalization of MMSN was confirmed using the ninhydrin test. Regorafenib (REGO), an anticancer drug, was used with a loading capacity of 77.5 μg mg−1. The drug release profiles from the carrier and the sensitivity of the interaction between MMSN and GQD to pH were examined, revealing that more drug release was observed in acidic pH. The cytotoxicity of the MMSN-REGO/GQD system was evaluated on colorectal cancer cell line SW-480 using MTT assay, and the results indicated that no cytotoxicity was observed for the MMSN/GQD carrier. Furthermore, the IC50 of REGO was significantly reduced from 85 μg ml−1 to 6 μg ml−1 in the loaded form. The response of MMSN/GQD nanoparticles to the external magnetic field exhibited the capability of the theragnostic system as an MRI contrast agent. Generally, biocompatible, theragnostic, pH-responsive, multifunctional MMSN/GQD can be considered promising candidates for treatment, MRI imaging, and hyperthermia in colorectal cancer treatment.