title: Preparation and characterization of biocompatible microcapsules of sodium cellulose sulfate/chitosan by means of layer-by-layer self-assembly.
abstract: A novel microcapsule system composed of sodium cellulose sulfate (NaCS) and chitosan was prepared by layer-by-layer (LbL) self-assembly technique. As a potential drug delivery system, it had several advantages in biocompatibility and biodegradation due to its use of natural polysaccharides. Some parameters in the preparation of the microcapsule, such as layers in the LbL process (up to 20 layers), chitosan viscosities (50, 100, and 200 mPas), outmost layer materials (NaCS or chitosan), and NaCl concentrations (0 M, 0.5 M, 1 M), were investigated to better understand their effects on the LbL process. A novel method for removing the core templates PLA and CaCO3 from the formed core-shell structure was proposed by addition of N-methyl pyrrolidone or EDTA-Na. This preparation process was well observed by a microscope-camera system. The hollow microcapsules were tested by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and scanning probe microscopy (SPM) to characterize their size, morphology, and surface. The results showed that the shell thickness of microcapsules was about 6 nm, and the average thickness of one layer of NaCS/chitosan polyelectrolyte complex was 1.5 nm. The molecular weight cutoff in sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed about 70 kDa by using of diffusion test with the cell lysate of Escherichia coli.
authors: Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, PR China.
authors: Yu-Liang
authors: YL
authors: Xie
authors: Ming-Jun
authors: MJ
authors: Wang
authors: Shan-Jing
authors: SJ
authors: Yao
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002214:Capsules / Q000737:chemistry*; D002482:Cellulose / Q000031:analogs & derivatives* / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry*; D004337:Drug Carriers; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D002214:Capsules; D004337:Drug Carriers; D014867:Water; D002482:Cellulose; D048271:Chitosan; C020254:cellulose sulfate