自组装法制备pH响应性马来酰化壳聚糖纳米粒子的研究

Preparation of Maleoyl Chitosan Nanoparticles by Self-Assembly and their pH Responsability

采用碳酸钠为催化剂,室温下制备了水溶性的马来酰化壳聚糖,研究了反应物投料比对酰化取代度以及产物水溶性的影响。红外光谱结果说明马来酸酐成功接枝到壳聚糖分子上;XRD结果说明马来酸酐酰化破坏了壳聚糖分子内和分子间的氢键作用,使水溶性大大提高。用Nano-ZS90Malvern仪器对不同pH值下的粒子粒径和Zeta电位进行测定,发现存在1个等电点:pH=3.01。文章首次采用自组装方法分别在醋酸、甲酸、乳酸溶液中制备得到三种不同的马来酰化壳聚糖纳米粒子并用SEM做了表征;DLS测试表明,当pH值增大后,三种纳米粒子粒径均由几十纳米溶胀到几百纳米,显示具有pH响应性。

The maleoyl chitosan(MCS)was prepared at room temperature by using sodium carbonate as catalyst.The effect of reactant feed ratio on the degree of substitution and water-solubility of acylated product was studied.FT-IR show that the maleic anhydride is successfully grafted onto chitosan molecule,X-ray diffractometry(XRD)results indicate that maleic anhydride acylating destructed the hydrogen bonds within and between molecules of chitosan,which greatly improved water-solubility.The particle size and zeta potential at different pH values were determined by using Nano-ZS90 Malvern Instruments.The isoelectric point is pH=3.01.Three different maleoyl Chitosan nanoparticles in acetic acid,formic acid,lactic acid solution were prepared by self-assembly approach for the first time,which were characterized by scanning electron microscopy(SEM).Dynamic light scattering(DLS)tests show that three kinds of nanoparticles swelled from tens of nanometers to hundreds of nanometers when the pH value increased,which displays the pH-responsive property.