Zinc imidazolate framework-8 as a promising nitric oxide carrier

Abstract

Uncontrollable release and unexpected release limit the use of nitric oxide (NO). To overcome this problem, we introduce ZIF-8 as a pH-responsive NO carrier. The flexible framework of ZIF-8 under the high-pressure condition causes the physically NO adsorption inside the SOD cage. ZIF-8 maintain the excellent gas storage ability under the physiological environment. The results show good pH-responsive ability. The gas could not be released out until the particle is in an acid condition. At low pH conditions, half of the gas is released in 1% of the total release duration. Interestingly, the half-release (t(1/2)) increases to 10% when the phosphate species exist in the acid surrounding. The gradual release can occur under neutral conditions with the existence of phosphate (t(1/2) 33%). From these results, we expect this ZIF-8 loading NO nanoparticles is lead to the design of innovative gas therapeutic delivery platforms using the advantage of the flexible framework for loading and releasing the gas molecule. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.