Insights in Behavior of Variably Formulated Alginate-Based Microcapsules for Cell Transplantation

Abstract

Alginate-based microencapsulation of live cells may offer the opportunity to treat chronic and degenerative disorders. So far, a thorough assessment of physical-chemical behavior of alginate-based microbeads remains cloudy. A disputed issue is which divalent cation to choose for a high performing alginate gelling process. Having selected, in our system, high mannuronic (M) enriched alginates, we studied different gelling cations and their combinations to determine their eventual influence on physical-chemical properties of the final microcapsules preparation, in vitro and in vivo. We have shown that used of ultrapure alginate allows for high biocompatibility of the formed microcapsules, regardless of gelation agents, while use of different gelling cations is associated with corresponding variable effects on the capsules' basic architecture, as originally reported in this work. However, only the final application which the capsules are destined to will ultimately guide the selection of the ideal, specific gelling divalent cations, since in principle there are no capsules that are better than others.

Alginate/Pluronic F127-based encapsulation supports viability and functionality of human dental pulp stem cell-derived insulin-producing cells

“…The swelling behaviour can occur mainly due to the osmotic factors. In PBS, high concentration of Na + can cause bead swelling, but in some studies, alginate beads showed the elasticity without showing membrane breakage [31]. In this experiment, high purity of alginate was employed to avoid over-swelling.…”

“…Assessment of bead swelling was aimed to determine the stability of the beads. In some conditions, alginate beads can swell resulted in the increasing of porosity and bead damage [31]. The swelling behaviour can occur mainly due to the osmotic factors.…”

Technologies and Formulation Design of Polysaccharide-Based Hydrogels for Drug Delivery

“…Generally, most of divalent cations (Ca 2+ , Sr 2+ , Cd 2+ , Co 2+ , Cu 2+ , Mn 2+ , Ni 2+ , Pb 2+ and Zn 2+ ) and some trivalent cations (Fe 3+ , Cr 3+ , Al 3+ , Ga 3+ , Sc 3+ and La 3+ ) can interact with G-blocks regions of alginate in a highly cooperative manner, generating a 3D network according to the so-called "egg-box" model [122]. Alginate affinity towards such polyvalent cations is directly dependent on the amount of G-blocks present in the alginate structure [123,124]. As demonstrated in [125] by numerous competitive inhibition studies, the main involved gelation mechanism is the dimerization of G residues.…”

Review of Advanced Hydrogel-Based Cell Encapsulation Systems for Insulin Delivery in Type 1 Diabetes Mellitus

“…However, this reaction is still poorly understood. In fact, in addition to the use of polycations in the microcapsules formulation, many other factors can be involved in the immune response such as the alginate purity, the biocompatibility of the materials conforming the microcapsule, the alginate chemical composition (guluronic/mannuronic ratio) and the size of the microcapsules [24,73,74].…”