The present study describes the facile preparation of acid/CO₂ stimuli-responsive sheddable nanoparticles based on carboxymethylated chitosan (CMCS). Commercially available CMCS was grafted with monomethoxy polyethylene glycol (mPEG) chains via an acid/CO₂ responsive linker, i.e., benzoic-imine, and then was used for the cross-linking with CaCl₂. With a high CMCS concentration up to 7 mg/mL, stable nanoparticles were successfully prepared. The particle size grew slightly with increasing the molecular weight of mPEG. When the concentration of CaCl₂ and the feed ratio of CMCS to mPEG increased, the particle size decreased at first and then increased after reaching a minimum size. When the particles were stimulated by CO₂ or acid, benzoicimine cleaved quickly, and mPEG fell off the nanoparticles simultaneously, and then flocculation and precipitation occurred. These sheddable nanoparticles might have potential application in the biomedical field including the intelligent drug delivery system.

本研究描述了基于羧甲基化壳聚糖（CMCS）的酸/ CO ₂刺激响应性可脱落的纳米粒子的简便制备。通过酸/ CO ₂响应性连接剂即苯甲亚胺将市售的CMCS接枝单甲氧基聚乙二醇（mPEG）链，然后用于与CaCl ₂交联。在高达7 mg / mL的高CMCS浓度下，成功制备了稳定的纳米颗粒。随着mPEG分子量的增加，粒径略有增加。当CaCl ₂的浓度和CMCS与mPEG的进料比增加时，粒度首先减小，然后在达到最小尺寸后增大。当颗粒被CO ₂刺激时在酸性或酸性条件下，苯甲酸杀菌剂迅速裂解，而mPEG同时从纳米颗粒上脱落，然后发生絮凝和沉淀。这些可脱落的纳米颗粒可能在包括智能药物输送系统在内的生物医学领域具有潜在的应用。