Characterization of the chitosan core-shell of CSL-gel
Scanning Electron Microscopy (SEM), Zeta potential analysis, Fourier Transform infrared spectrometry (FTIR) and elemental analysis were performed by Beijing Zhongke Baitei Technical Service Co., LTD. Briefly, SEM (SU-8020, Hitachi, Japan) was used for the observation of the surface composition of the hydrogel according to manufactories instruction. Zetasizer Nano ZS90 (Malvern Panalytical, Almelo, Netherlands) was used to measure the surface charge of the hydrogel. FTIR spectrometer Nicolet 6700 (Thermo Scientific, USA) was used to collect infrared spectra in the range 4000–400 cm−1 by 32 scans following the manufacturer’s instructions. Elemental analyzer (Vario EL cube, Elementar Analysensysteme Madison, WI, U.S.A, Frankfurt, Germany) were used to analyze the elemental composition on the formation of the chitosan shell in the surface of the hydrogel.