Bodnar Magdolna, Hartmann John F, Borbely Janos
Department of Colloid and Environmental Chemistry, University of Debrecen, H-4010 Debrecen, Hungary.
Biomacromolecules. 2006 Nov;7(11):3030-6. doi: 10.1021/bm0605053.
The present investigation describes the synthesis and characterization of novel biodegradable nanoparticles based on chitosan. Poly(ethylene glycol) dicarboxylic acid was used for intramolecular cross-linking of the chitosan linear chains. The condensation reaction of carboxylic groups and pendant amino groups of chitosan was performed by using water-soluble carbodiimide. The prepared nanosystems were stable in aqueous media. The structure of the products was determined by nuclear magnetic resonance (NMR) spectroscopy, and the particle size was identified by dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. It was found that biodegradable cross-linked chitosan nanoparticles experienced considerable swelling because of the length and flexibility of the cross-linking agent. The aqueous solutions or dispersions of nanoparticles were stable and clear or mildly opalescent systems depending on the ratio of cross-linking and molecular weight of chitosan, findings consistent with values of transmittance above 75%. Particle size measured by TEM varied in the range of 4-24 nm. In the swollen state, the average size of the individual particles measured by DLS was in the range of 50-120 nm depending on the molecular weight of chitosan and the ratio of cross-linking.
本研究描述了基于壳聚糖的新型可生物降解纳米颗粒的合成与表征。聚（乙二醇）二羧酸用于壳聚糖线性链的分子内交联。壳聚糖的羧基与侧链氨基的缩合反应通过使用水溶性碳二亚胺进行。制备的纳米系统在水性介质中稳定。产物的结构通过核磁共振（NMR）光谱确定，粒径通过动态光散射（DLS）和透射电子显微镜（TEM）测量确定。发现可生物降解的交联壳聚糖纳米颗粒由于交联剂的长度和柔韧性而经历了相当大的溶胀。纳米颗粒的水溶液或分散体是稳定的，根据壳聚糖的交联比例和分子量，体系为澄清或轻度乳光，透光率高于75%的结果与之相符。通过TEM测量的粒径在4-24nm范围内变化。在溶胀状态下，通过DLS测量的单个颗粒的平均尺寸根据壳聚糖的分子量和交联比例在50-120nm范围内。
