title: Preparation and microscopy examination of alginate-poly-L-lysine-alginate microcapsules.
abstract: Ca-alginate-poly-l-lysine-alginate (APA-Ca) and Ba-alginate-poly-l-lysine-alginate (APA-Ba) microcapsules were prepared and their thickness and surface were examined by light microscopy and scanning electron microscopy. Specifically, light microscopy with frozen section was used to visualize and quantify the thickness of APA membrane, and monitor temporal changes in the thickness of microcapsules during a month long culture in vitro. The section graph of APA microcapsule represents the accurate measurement of layer thickness of APA-Ca with diameter 900 ± 100 and 500 ± 100 μm at 6.01 ± 1.02 and 9.54 ± 2.42 μm (p < 0.05), and layer thickness of APA-Ba with diameter 900 ± 100 and 500 ± 100 μm at 5.47 ± 0.90 and 8.21 ± 1.97 μm (p < 0.05), regardless of the alginate composition used to generate the microcapsules. The microcapsule was stable during the culture for 30 days in vitro. Field emission scanning electron microscopy with freeze drying method was used to detect the surface and thickness of dried microcapsules. From the results, the outer surface of APA-Ca and APA-Ba membrane were smooth and dense, the film thickness of the APA-Ca was about 450-690 nm, while the APA-Ba was approximately 335 nm. In vivo experiment, little significant difference was seen in the change of film thickness of microcapsules in intrapertioneal site for 30 days after transplantation (p > 0.05), except that the recovery of APA-Ba was higher than the APA-Ca microcapsules. The paper showed an easy method to prepare APA-Ca and APA-Ba, and examine their thickness and surface, which could be utilized to study other types of microcapsules.
authors.affiliation: School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing , China .
authors.forename: Hong-Xing
authors.initials: HX
authors.lastname: Fu
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Lan-Lan
authors.initials: LL
authors.lastname: Wu
authors.forename: Ying-Zheng
authors.initials: YZ
authors.lastname: Zhao
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Xu
authors.forename: Yan-Lin
authors.initials: YL
authors.lastname: Zhu
authors.forename: Shen-Liu
authors.initials: SL
authors.lastname: Xue
authors.forename: Da-Wang
authors.initials: DW
authors.lastname: Wang
authors.forename: Cheng-Yang
authors.initials: CY
authors.lastname: Liu
authors.forename: Shu-Lin
authors.initials: SL
authors.lastname: Yang
authors.forename: Xiao-Kun
authors.initials: XK
authors.lastname: Li
mesh_terms: D000464:Alginates / Q000737:chemistry*; D001464:Barium / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D002214:Capsules / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D004355:Drug Stability; D008853:Microscopy; D011107:Polylysine / Q000031:analogs & derivatives* / Q000737:chemistry; D013499:Surface Properties
chemical_list: D000464:Alginates; D002214:Capsules; C051546:alginate-polylysine-alginate; D001464:Barium; D011107:Polylysine; D002118:Calcium
keywords: Alginate; frozen section; microcapsules; poly-l-lysine; scanning electron microscopy