Physicochemical model of alginate–poly-l-lysine microcapsules defined at the micrometric/nanometric scale using ATR-FTIR, XPS, and ToF-SIMS
| Autor: | Susan K. Tam, Martin Ménard, Jean-Pierre Hallé, Stefania Polizu, Julie Dusseault, L'Hocine Yahia |
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| Rok vydání: | 2005 |
| Předmět: |
Models
Molecular Materials science Biocompatibility Alginates Surface Properties Cell Culture Techniques Biophysics Analytical chemistry Biocompatible Materials Bioengineering engineering.material Biomaterials Glucuronic Acid X-ray photoelectron spectroscopy Coating Materials Testing Spectroscopy Fourier Transform Infrared Monolayer Nanotechnology Polylysine Fourier transform infrared spectroscopy Hexuronic Acids Microchemistry Spectrometry X-Ray Emission Microspheres Secondary ion mass spectrometry Membrane Models Chemical Chemical engineering Mechanics of Materials Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Attenuated total reflection Ceramics and Composites engineering |
| Zdroj: | Biomaterials. 26:6950-6961 |
| ISSN: | 0142-9612 |
| Popis: | Alginate–poly- l -lysine–alginate (APA) microcapsules are currently being investigated as a means to immuno-isolate transplanted cells, but their biocompatibility is limited. In this study, we verified the hypothesis that poly- l -lysine (PLL), which is immunogenic when unbound, is exposed at the APA microcapsule surface. To do so, we analysed the microcapsule membrane at the micrometric/nanometric scale using attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. The results indicate that PLL and alginate molecules interact within the membrane. PLL exists in considerable amounts near the surface, contributing to the majority of the carbon within the outermost 100 A of the membrane. PLL was also detected at the true surface (the outermost monolayer) of the microcapsules. The exposure of PLL does not appear to result from defects in the outer alginate coating. This physicochemical model of APA microcapsules could explain their immunogenicity and will play an important role in the optimization of the microcapsule design. |
| Databáze: | OpenAIRE |
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