Host: The Japanese Society of Toxicology
Name : The 50th Annual Meeting of the Japanese Society of Toxicology
Date : June 19, 2023 - June 21, 2023
Surface charges of a nanomedicine is one of the multiple factors that would affect its therapeutic and toxicologic outcomes. Positively charged nanomaterials have been shown to have high tendency to interact with cells. Accordingly, positively charged nanoparticles are usually more toxic and have poor pharmacokinetic properties, compared with negatively or neutrally charged particles. Previously, we developed a method to prepare organosilica nanoparticles, which are positively charged at physiological pH and carry two functional groups (thiol and amine) for drug conjugation and delivery. This study aimed to control the cellular interaction and uptake of positively charged organosilica nanoparticles by modifying the particle surface with adsorbed serum proteins. Protein adsorption and binding of nanoparticles were fully explored by adjusting various factors, including pH, temperature, time, etc. Particle size and surface charges were measured by DLS, and TEM was used to confirm protein adsorption. The amount of protein adsorbed were further quantified by a protein assay. Cellular uptake were evaluated by fluorescence microscopy and cytotoxicity of nanoparticles were measured by MTT assays. The results demonstrated that, after protein adsorption, particle size increases from 91.87±0.88 nm to 149.57±1.82 nm. The surface charge will switch from positive to negative (from 53.13±3.35 mV to -17.07±0.65 mV), confirming successful protein adsorption on the surface of nanoparticles. Protein adsorption efficiency ranges from 0.01% to 1.98%, depending on preparation condition. The quantitative cellular uptake and cytotoxicity data will be presented in the meeting.
