Effect of poly-L-lysine coating on macrophage activation by alginate-based microcapsules: Assessment using a new in vitro method
✍ Scribed by Sandy Juste; Mélanie Lessard; Nathalie Henley; Martin Ménard; Jean-Pierre Hallé
- Publisher
- John Wiley and Sons
- Year
- 2005
- Tongue
- English
- Weight
- 288 KB
- Volume
- 72A
- Category
- Article
- ISSN
- 1549-3296
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✦ Synopsis
Abstract
The characteristics of the microcapsule surface, which interacts directly with the host macrophages, may have a role in the biocompatibility of alginate‐poly‐L‐lysine (PLL)‐alginate (APA) microcapsule. The objectives of the study were: 1) to develop and validate a simple, rapid, and sensitive in vitro method for assessing microcapsule biocompatibility, based on microcapsule coincubation with macrophages and measurement, by reverse transcriptase‐polymerase chain reaction, of cytokine mRNA expression, and 2) to evaluate the effect of alginate purification and PLL coating on macrophage activation. The mRNA expression of tumor necrosis factor‐α and interleukin‐1β was significantly higher when macrophages were coincubated with beads made with nonpurified compared with purified alginate (p < 0.01, p < 0.05, respectively) and negative control (p < 0.001) or with APA microcapsules compared with non‐PLL‐coated alginate beads and negative control (p < 0.001). The mRNA expression of interleukin‐6 differed significantly only when APA microcapsules were compared with a negative control (p < 0.05). These results confirm that alginate purification improves microcapsule biocompatibility, and suggest that PLL is not completely covered and/or neutralized by the second alginate incubation and thus has a role in the host macrophage activation. The assay is sensitive to both alginate contaminants and microcapsule surface characteristics and may be a useful tool for the development of biocompatible microcapsules. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 389–398, 2005