Abstract：
Polysaccharide-based nanogels offer a wide range of chemical compositions and are of great interest due to their biodegradability, biocompatibility, non-toxicity, and their ability to display pH, temperature, or enzymatic response. In this work, we synthesized monodisperse and tunable pH-sensitive nanogels by crosslinking, through reductive amination, chitosan and partially oxidized maltodextrins, by keeping the concentration of chitosan close to its overlap concentration, i.e. in the dilute and semi-dilute regime. The chitosan/maltodextrin nanogels presented sizes ranging from 63 ± 9 to 279 ± 16 nm, showed quasi-spherical and cauliflower-like morphology, reached a ζ-potential of +36 ± 2 mV and maintained a colloidal stability for up to 7 weeks. It was found that the size and surface charge of nanogels depended both on the oxidation degree of maltodextrins and chitosan concentration, as well as on its degree of acetylation and protonation, the latter tuned by pH. The pH-responsiveness of the nanogels was evidenced by an increased size, owed to swelling, and ζ-potential when pH was lowered. Finally, maltodextrin-chitosan biocompatible nanogels were assessed by cell viability assay performed using the HEK293T cell line.
摘要：
基于多糖的纳米凝胶提供了广泛的化学组成，并且由于其生物降解性而引起了极大的兴趣，生物相容性，无毒性，以及它们显示pH值的能力，温度,或酶反应。在这项工作中,我们通过交联合成了单分散和可调的pH敏感纳米凝胶，通过还原胺化，壳聚糖和部分氧化麦芽糊精，通过将壳聚糖的浓度保持在重叠浓度附近，即在稀释和半稀释制度中。壳聚糖/麦芽糖糊精纳米凝胶的尺寸范围为63±9至279±16nm，呈准球形和花椰菜状形态，达到+36±2mV的ζ电位，并保持胶体稳定性长达7周。研究发现，纳米凝胶的尺寸和表面电荷取决于麦芽糊精的氧化程度和壳聚糖的浓度，以及它的乙酰化和质子化程度，后者由pH调节。纳米凝胶的pH响应性通过增加的尺寸来证明，由于肿胀，pH降低时的ζ电位。最后,通过使用HEK293T细胞系进行的细胞活力测定来评估麦芽糖糊精-壳聚糖生物相容性纳米凝胶。
