Effect of poly‐L‐lysine coating on macrophage activation by alginate‐based microcapsules: Assessment using a new in vitro method
- 24 January 2005
- journal article
- research article
- Published by Wiley in Journal of Biomedical Materials Research Part A
- Vol. 72A (4), 389-398
- https://doi.org/10.1002/jbm.a.30254
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, 2005Keywords
Funding Information
- The Canadian Diabetes Association
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