4.4.1 Preparation of CMC-PEG hydrogel
PEG-DA was prepared in large quantities by the esterification reaction of PEG-4000 and propionic acid under the catalysis ofp -toluenesulfonic acid in toluene according to the literature.[30] After purification, PEG-DA and CMC of equal molar ratio of functional groups were dissolved in the PBS solution of ANVs or THB@ANVs with a weight percent of 4%, the solution was stored at 4 ℃ overnight to gelation.