REDOX-RESPONSIVE SILICA NANOPARTICLES: EVOLUTION OF MORPHOLOGY, COLLOIDAL STABILITY, AND SURFACE INTERACTIONS

Nanoparticles (NPs) have been employed in the biomedical field; however, difficulties and biological barriers (e.g., bioaccumulation) hinder the transposition of nanomaterials developed on the bench to medical applications1. Biologically relevant media, such as the tumor microenvironment, has an overexpression of reducing agents (e.g., glutathione) that stimulates the cleavage of chemical bonds found in NPs' structure, preventing bioaccumulation2. Since chemical cleavage only occurs in these microenvironments, NPs exhibit high specificity and become biodegradable. In order to be most effective, they should also have colloidal stability and targeting effectiveness after biological barriers for posterior arrival at the tumor microenvironment. Here, we study how redox-responsive silica NPs evolved in morphology and colloidal stability under degradation conditions. Sulfide-based biodegradable silica nanoparticles (S-SiO2@NP) were synthesized, and their degradation in the presence of reducing agents was evaluated. Dynamic light scattering (DLS) reveals S-SiO2@NP's colloidal stability in relevant biological media, and transmission scanning electron microscopy (STEM) identified the evolution of S-SiO2@NP morphology. Thus, S-SiO2@NP are a promising bioresponsive platform and contribute to advancing the development of nanomaterials with biomedical interests.