Reducing responsive targeted polymeric micelle for mucus penetration and preparation method of polymeric micelle

The invention relates to a reducing responsive targeted polymeric micelle for mucus penetration and a preparation method of the polymeric micelle. An amphiphilic polymeric combination is formed by combining PLGA (poly (lactic-co-glycolic acid)) and PEG (polyethylene glycol) through a reducing responsive disulfide bond, and the reducing responsive polymeric micelle is formed by assembling the polymeric combination, so that excellent performances of mucus penetration, reducing responsive bond breaking and targeted cell-mediated endocytosis are achieved, and the effective grain size of the polymeric micelle is 70-110nm, so that the polymeric micelle is more uniform in grain size; the surface of the micelle which is covered in PEG is neutral, so that cytotoxicity is low; the polymeric micelle is capable of penetrating into a bottom cell layer in a mucus layer and a glutathione solution is injected as the polymeric micelle reaches the bottom cells, at which time the reducing responsive disulfide bond is broken, PEG protection is removed, covered targeted folic acid is exposed and is subjected to specific combination with a folic acid receptor which undergoes over-expression on the surface of a cell membrane of focus cells, and an endocytosis action is mediated by virtue of the folic acid receptor, so that cell-entering efficiency of nano carriers is improved and more carriers enter the cells to take a sustained/controlled-release effect on medicines; therefore, a therapeutic effect is enhanced.