The On-Off chiral mesoporous silica nanoparticles for delivering achiral drug in chiral environment

In the current stage, the On-Off mechanism of chiral mesoporous silica nanoparticles (CMSN) for delivering achiral drug in chiral environment has rarely been reported. Herein, On-Off chiral mesoporous silica nanoparticles (On-Off-D-CMSN and On-Off-L-CMSN) were successfully synthesized and its particular contribution in delivering achiral drug indometacin (IMC) in chiral environment was mainly studied. The as-synthesized On-Off-D-CMSN and On-Off-L-CMSN were verified by fourier transform infrared spectrometer and circular dichroism. The transmission electron microscope test and nitrogen adsorption/desorption analysis showed that On-Off-D-CMSN and On-Off-L-CMSN were regular spheres with concealed pore channels. The zeta potential analysis demonstrated that the grafting functional groups distributed on the inner and outer surfaces of On-Off-D-CMSN and On-Off-L-CMSN. Through dissolution experiment, the drug release of IMC loaded On-Off-D-CMSN (84%) and IMC loaded On-Off-L-CMSN (70%) were about 2.4 and 2.0 times higher than pure IMC (35%) in pH 6.8 phosphate buffer solution (PBS), respectively. IMC loaded On-Off-D-CMSN and IMC loaded On-Off-L-CMSN exerted different chiral recognition functions with On-Off mechanism in in-vitro chiral environment (pH 6.8 PBS-L and pH 6.8 PBS-D). The results of anti-inflammation pharmacodynamics further demonstrated that On-Off-D-CMSN and On-Off-L-CMSN can trigger chiral biological environment to achieve on or off chiral recognition functions. The unique advantages of On-Off chiral mesoporous silica nanoparticles in triggering chiral biological environment can provide valuable instruction for designing drug delivery system.