title: Assembly of multilayer microcapsules on CacO3 particles from biocompatible polysaccharides.
abstract: Multilayer microcapsules were fabricated by layer-by-layer (LbL) assembly of natural polysaccharides onto CaCO3 particles, following with core removal. The micron-sized CaCO3 particles were synthesized by reaction between Ca(NO3)2 and Na2CO3 solutions in the existence of carboxylmethyl cellulose (CMC). The incorporated amount of CMC in the CaCO3 particles was found to be 5.3 wt% by thermogravimetric analysis. Two biocompatible polysaccharides, chitosan and sodium alginate were alternately deposited onto the CaCO3(CMC) templates to obtain hollow microcapsules. Regular oscillation of surface charge as detected by zeta potential demonstrated that the assembly proceeded surely in a LbL manner. The stability of the microcapsules was effectively improved by cross-linking of chitosan with glutaraldehyde. The chemical reaction was verified by infrared spectroscopy. The microcapsules thus fabricated could be spontaneously filled with positively charged low molecular weight substances such as rhodamine 6G and showed good biocompatibility, as detected by in vitro cell culture.
authors.affiliation: Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
authors.forename: Qinghe
authors.initials: Q
authors.lastname: Zhao
authors.forename: Zhengwei
authors.initials: Z
authors.lastname: Mao
authors.forename: Changyou
authors.initials: C
authors.lastname: Gao
authors.forename: Jiacong
authors.initials: J
authors.lastname: Shen
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D002214:Capsules / Q000138:chemical synthesis* / Q000737:chemistry; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry*; D049109:Cell Proliferation / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry; D016503:Drug Delivery Systems; D005347:Fibroblasts; D006801:Humans; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry
chemical_list: D000464:Alginates; D001672:Biocompatible Materials; D002214:Capsules; D003432:Cross-Linking Reagents; D048271:Chitosan; D002119:Calcium Carbonate; D002266:Carboxymethylcellulose Sodium