PH-sensitive antioxidant nano-carrier and preparation method and application thereof

Abstract

The invention relates to a preparation method of a pH-sensitive antioxidant nano-carrier. The preparation method comprises the following steps: (1) dissolving chitosan in distilled water to obtain a chitosan solution; (2) completely dissolving N-acetyl-L-histidine in dimethyl sulfoxide, and then adding N, N'-diimidazole; evaporating the solution to dryness after stirring, adding the chitosan solution and performing stirring, and performing freeze-drying after dialysis to obtain N-acetyl-L-histidine grafted chitosan; (3) taking coupling agents EDC and NHS, and adding N-acetylcysteine after uniform stirring to obtain carboxyl-activated N-acetylcysteine; and (4) mixing the N-acetyl-L-histidine grafted chitosan with the carboxyl-activated N-acetylcysteine, and then adding the mixture into a TEMED / HCI buffer solution; and reacting for 6-10h under magnetic stirring, performing dialysis by using a dialysis bag, and then carrying out freeze-drying treatment to obtain the pH-sensitive antioxidant nano-carrier. The antioxidant nano-carrier prepared by the invention can promote the survival of stem cells, and efficiently delivers and releases drugs in an acidic microenvironment in a targeted manner.

Description

technical field [0001] The present invention relates to the technical field, more particularly, it relates to a pH-sensitive antioxidant nanocarrier and its preparation method and application. Background technique [0002] The application of bone marrow mesenchymal stem cells in bone injury repair is of great value. However, bone defects caused by trauma, surgery and other reasons will destroy the blood supply to the bone defect area to varying degrees, resulting in a state of relative ischemia and hypoxia in the bone defect area. At the same time, due to the local inflammatory microenvironment, metabolites A variety of factors, such as accumulation, can lead to a decrease in the survival rate of transplanted stem cells, which severely limits the important role of bone marrow mesenchymal stem cells in the repair of bone damage. Therefore, in the repair of bone injury, how to promote the survival of transplanted stem cells in the scaffold, improve their anti-oxidative damage...

AI Technical Summary

Problems solved by technology

At present, bone tissue engineering still faces the low survival rate of transplanted stem cells due to local ischemia, hypoxia, acidic microenvironment, accumulation of metabolites and other factors, which seriously affects the efficiency of bone defect repair.

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