Drug release kinetics of artemisinin sustained-release particles with two sizes for algal inhibition in different media

To avoid the disadvantage that millimeter level artemisinin particles coated with chitosan alginate (CS/AL/AT) are easy to settle and improve the dispersion of granules in water, improved chitosan covered alginate artemisinin particles by ultrasonic technology combined with ion crosslinking method (CS/AL/AT-US) were prepared in this study. The release kinetics of two kinds of particles under different media conditions (temperature, ionic strength, pH, algal liquid, and Taihu Lake water) were studied. The physicochemical characterization showed that the diameter and zeta potential of the CS/AL/AT-US were 1189.5 nm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$nm$$\end{document} and − 38.0 mV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$mV$$\end{document}, respectively. Here, the drug release of chitosan-coated artemisinin alginate particles is affected by the temperature, pH, and ionic strength of the release medium. Whether CS/AL/AT or CS/AL/AT-US, drug release increased with the increase of temperature and ionic strength, but decreased with the increase of pH. More importantly, the release kinetics study showed that the release mechanism of the CS/AL/AT-US in Taihu Lake water and algae liquid is matrix dissolution, while the release of CS/AL/AT in Taihu Lake water was controlled by diffusion and skeleton dissolution. The growth experiment of cyanobacteria showed that the CS/AL/AT-US have a long-term inhibitory effect on algae cells, and the inhibitory effect on cyanobacteria increased with the increase of dosing concentration. Our study clearly shows that the particles with reduced diameter have the characteristics of rapid dispersion and continuous release, and have the potential to be applied to the control of cyanobacteria bloom.