Alginate-Based Cell Encapsulation Using Different Crosslinker Elements

Abstract

Alginate microcapsules are the most frequently used materials for cell transplantation. Different crosslinkers affect crosslinking affinity, which has a significant influence on microcapsule properties. The objective was to prepare in vitro microcapsules using calcium, barium, iron, manganese, nickel, and strontium as divalent cations to observe their potential for use in cell transplantation. Sodium alginate was added dropwise to the individually prepared crosslinkers to observe diffusion-based gelling. Alginate microcapsules were investigated regarding capsule stability, physiological properties, and cell viability. After 30 days of incubation, cell viability was greater than 90% for the cell-encapsulated microcapsules when crosslinked with CaCl2 and NiCl2. Viability decreased in the following order: CaCl2 > NiCl2 > BaCl2 > SrCl2 > MnCl2 > FeCl2. A compression test was performed to investigate the required force to deform 30% of microcapsules, and only MnCl2, FeCl2 (180 mM), and NiCl2 (50 mM) demonstrated higher resistance to the applied force than CaCl2. Except for the FeCl2 group, all cell-encapsulated microcapsules remained intact for 45 days. Potential sensitivities to CaCl2 during cell transplantation may compel alternative crosslinker usage, and our study revealed that NiCl2 and BaCl2 can be used as alternative crosslinkers to CaCl2 due to their high cell viability and consistent stability. © World Scientific Publishing Company.