Abstract
Microencapsulation is a commonly used technique for immunoprotection of engrafted therapeutic cells We investigated a library of capsule formulations to determine the most optimal formulation for pancreatic beta islet cell transplantation, using barium as the gelating ion and clinical-grade protamine sulfate (PS) as a new cationic capsule cross-linker Barium-gelated alginate/PS/alginate microcapsules (APSA, diameter = 444 ± 21 μm) proved to be mechanically stronger and supported a higher cell viability as compared to conventional alginate/poly- l-lysine/alginate (APLLA) capsules Human pancreatic islets encapsulated inside APSA capsules, gelated with 20 m m barium as optimal concentration, exhibited a sustained morphological integrity, viability, and functionality for at least 3-4 weeks in vitro, with secreted human C-peptide levels of 0.2-160 pg/ml/islet Unlike APLLA capsules that are gelled with calcium, barium-APSA capsules are intrinsically radiopaque and, when engrafted into mice, could be readily imaged in vivo with micro-computed tomography (CT) Without the need of adding contrast agents, these capsules offer a clinically applicable alternative for simultaneous immunoprotection and real-time, non-invasive X-ray/CT monitoring of engrafted cells during and after in vivo administration.
Original language | English (US) |
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Pages (from-to) | 4681-4689 |
Number of pages | 9 |
Journal | Biomaterials |
Volume | 33 |
Issue number | 18 |
DOIs | |
State | Published - Jun 2012 |
Keywords
- Barium
- CT imaging
- Diabetes
- Islet cell
- Microcapsule
ASJC Scopus subject areas
- Biophysics
- Bioengineering
- Ceramics and Composites
- Biomaterials
- Mechanics of Materials