title: Preparation, complexation mechanism and properties of nano-complexes of Astragalus polysaccharide and amphiphilic chitosan derivatives.
abstract: To improve the small intestinal absorption efficacy of Astragalus polysaccharides (APS) through oral administration, amphiphilic chitosan derivatives conjugated with deoxycholic acid residues in the absence and presence of vitamin B12residues (DA-Chit and VB12-DA-Chit, respectively) were synthesized and characterized by FTIR and NMR spectroscopy. APS and the amphiphilic chitosan derivatives formed the nano-complexes with positive zeta potentials in the size of 100-150nm observed using scanning electron microscopy. To investigate the fluorescent properties of APS, a Congo red residue-conjugated APS derivative (CR-APS) was synthesized. Fluorescence spectroscopy and resonance light scattering spectroscopy confirmed the formation of the CR-APS/DA-Chit nano-complex as a result of electrostatic interaction. The APS/DA-Chit and APS/VB12-DA-Chit nano-complexes were not toxic against the human colon adenocarcinoma (Caco-2) cells. The APS/VB12-DA-Chit nano-complex exhibited high permeation through intestinal enterocytes using the Caco-2 cell model, which could be beneficial to small intestinal absorption of humans.
authors.affiliation: Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-Based Composites, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Minghua
authors.initials: M
authors.lastname: Lai
authors.affiliation: Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China.
authors.forename: Jingnan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-Based Composites, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Jiayun
authors.initials: J
authors.lastname: Tan
authors.affiliation: Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-Based Composites, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Jiahao
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-Based Composites, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Zhang
authors.affiliation: Research Center of Translational Medicine, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China. Electronic address: dengyub@mail.sysu.edu.cn.
authors.forename: David Y B
authors.initials: DY
authors.lastname: Deng
authors.affiliation: Department of Polymer and Material Science, School of Chemistry, Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Guangdong Provincial Key Laboratory for High Performance Polymer-Based Composites, Sun Yat-Sen University, Guangzhou 510275, China. Electronic address: yanglq@mail.sysu.edu.cn.
authors.forename: Liqun
authors.initials: L
authors.lastname: Yang
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry*; D018938:Caco-2 Cells; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D006801:Humans; D053761:Nanocomposites / Q000737:chemistry*; D011134:Polysaccharides / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity
chemical_list: D011134:Polysaccharides; D048271:Chitosan
keywords: Astragalus polysaccharide; Chitosan; Fluorescence spectroscopy; Interaction; Small intestinal absorption; Vitamin B(12)